Upload 51 files

.gitattributes

@@ -58,3 +58,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 # Video files - compressed
 *.mp4 filter=lfs diff=lfs merge=lfs -text
 *.webm filter=lfs diff=lfs merge=lfs -text
+assets/icons/icon.ico filter=lfs diff=lfs merge=lfs -text

.gitignore

@@ -0,0 +1,74 @@
+# Logs
+logs/
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Dependency directories
+node_modules/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+.env.test
+.env.local
+.env.*.local
+
+# Electron build output
+dist/
+out/
+build/
+
+# OS files
+.DS_Store
+Thumbs.db
+desktop.ini
+
+# IDE files
+.vscode/
+.idea/
+*.sublime-project
+*.sublime-workspace
+
+# Test files
+test-file.js
+test-results/
+
+# Security sensitive files
+private_key.pem
+*.key
+*.pem
+checksums.json
+checksums.sig
+
+# User data
+*.sqlite
+*.db

.npmignore

@@ -0,0 +1,58 @@
+# Development files
+.gitignore
+.git/
+.vscode/
+.idea/
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Test files and coverage
+test/
+coverage/
+*.test.js
+*.spec.js
+
+# Build and dist files
+dist/
+build/
+node_modules/
+
+# OS generated files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Temporary files
+*.tmp
+*.temp
+*.swp
+*.swo
+*~
+
+# Old electron-specific files (not needed for npm package)
+emoji-cleaner.bat
+emoji-cleaner.sh
+
+# Documentation build files
+docs/
+
+# Environment files
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# Editor files
+*.sublime-project
+*.sublime-workspace
+
+# Backup files
+backup-*/
+emoji-backup-*/

README.md

@@ -0,0 +1,307 @@
+---
+license: other
+language:
+  - en
+tags:
+  - code-analysis
+  - static-analysis
+  - javascript
+  - electron
+  - emoji-cleaner
+  - junk-sweeper
+  - plugin-management
+  - desktop-app
+  - electron-app
+  - security
+---
+# Chahua Markdown Video Studio
+
+![Chahua Markdown Video Studio](assets/image/chahuadev-markdown-presenter.png)
+![Version](https://img.shields.io/badge/version-1.0.0-blue.svg)
+![Electron](https://img.shields.io/badge/electron-28.0.0-47848f.svg)
+
+> Author every slide, timing, and presentation configuration in markdown—preview and export videos without leaving your deck.
+
+Chahua Markdown Video Studio turns a single markdown file into a cinematic video. Frontmatter drives presentation presets, export settings, and security-sensitive metadata while the renderer timeline stays perfectly in sync between preview and export.
+
+---
+
+## Why Markdown-First?
+
+- Single source of truth for content, timings, transitions, narration cues, and assets.
+- Deterministic timeline JSON shared by the renderer and upcoming headless export pipeline.
+- Presentation presets round-trip through frontmatter so writers and designers stay aligned.
+- Actionable diagnostics inside the Markdown tab highlight validation issues in context.
+
+---
+
+## Key Capabilities
+
+- Markdown editor with live sync and diagnostics (`Sync Markdown` button).
+- Timeline tab showing per-slide durations, timecodes, and tracked assets.
+- Export tab for resolution, FPS, and quality settings backed by frontmatter.
+- Presentation settings panel (transitioning from static templates) that writes preset choices back into the deck and restyles the preview.
+- Secure preload bridge (`security-core.js`) enforcing filesystem, hashing, and rate limits.
+
+> Current focus is WebM preview/export. Legacy GIF export returns after the shared timeline engine stabilises.
+
+---
+
+## Table of Contents
+
+- [Quick Start](#quick-start)
+- [Markdown Authoring Workflow](#markdown-authoring-workflow)
+- [Markdown Format Cheatsheet](#markdown-format-cheatsheet)
+- [Application Layout](#application-layout)
+- [Documentation](#documentation)
+- [Project Structure](#project-structure)
+- [Security Posture](#security-posture)
+- [Development Notes](#development-notes)
+- [Contributing](#contributing)
+- [Credits & Contact](#credits--contact)
+
+---
+
+## Quick Start
+
+```bash
+# Clone the repository
+git clone https://github.com/chahuadev/chahuadev-markdown-presenter.git
+
+# Enter the project
+cd chahuadev-markdown-presenter
+
+# Install dependencies
+npm install
+
+# Launch the app
+npm start
+```
+
+Optional scripts:
+
+```bash
+npm run dev    # Verbose logging
+npm run build  # Package the Electron app
+```
+
+---
+
+## Markdown Authoring Workflow
+
+1. **Open the app** with `npm start`.
+2. **Markdown tab**
+   - Paste or edit your deck in the editor.
+   - Use `Load Sample Deck` for a guided example.
+   - Click `Sync Markdown` to parse slides, refresh the timeline, and update the stage text.
+3. **Timeline tab**
+   - Review total duration and per-slide timings.
+   - Confirm asset checklist items (images, audio) and resolve pending markers.
+4. **Presentation Settings tab**
+   - Select a preset; the choice updates frontmatter (`presentation.preset` with a `template` fallback) and restyles the stage.
+   - Presentation Settings is the recommended system going forward; the legacy `template` field remains only so decks from earlier versions still render correctly.
+5. **Export tab**
+   - Adjust `video.resolution`, `video.fps`, and `video.quality`. Values sync back to frontmatter.
+6. **Preview / Export**
+   - `Preview Timeline` plays the parsed deck against the live stage.
+   - `Export Video` records a WebM through the native `VideoRenderer` and saves it securely.
+
+---
+
+## Markdown Format Cheatsheet
+
+```markdown
+---
+presentation:
+   preset: professional
+   fonts:
+      heading: "'Montserrat', 'Arial', sans-serif"
+   colors:
+      accent: "#60a5fa"
+   animations:
+      slideTransition: slide
+template: professional  # legacy fallback for older builds
+video:
+  resolution: 1920x1080
+  fps: 60
+  quality: 0.95
+---
+
+# Introduction
+subtitle: Markdown Video Studio
+duration: 4
+
+Welcome to the Markdown-first workflow.
+
+---
+
+# Feature Highlights
+duration: 6
+
+- Native WebM encoding with MediaRecorder API
+- Real-time preview and timeline visualization
+- Frontmatter configuration sync
+- Truly offline-first architecture
+
+![Feature Demo](assets/image/screenshot.png)
+
+---
+
+# Conclusion
+subtitle: Built with Electron + Canvas
+duration: 5
+
+Thank you for watching!
+```
+
+**Slide Syntax:**
+- Each slide separated by `---`
+- `# Title` - Main heading (required)
+- `subtitle: text` - Optional subtitle
+- `duration: N` - Slide duration in seconds (default: 5)
+- Standard Markdown: lists, **bold**, *italic*, images
+
+**Frontmatter Options:**
+- `presentation.preset:` default, professional, minimal, creative
+- `presentation.fonts.heading|body|code:` Any supported font token from `presentation-config.js`
+- `presentation.colors.primary|accent|background:` Hex colors (e.g. `#3b82f6`)
+- `presentation.animations.slideTransition:` fade, slide, none
+- `video.resolution:` 1920x1080, 1280x720, 3840x2160
+- `video.fps:` 30, 60
+- `video.quality:` 0.8 - 1.0
+- `template:` Legacy fallback key while presets fully replace template cards
+
+Extended directives for transitions and narration cues are outlined in `docs/EN/MARKDOWN_VIDEO_PLAN.md`.
+
+---
+
+## Application Layout
+
+- **Stage (left panel)**: live preview of intro, timeline snapshot, and outro styled by the active preset.
+- **Markdown**: editor, diagnostics panel, summary card, and quick actions (load sample, import from disk, open workspace folder).
+- **Timeline**: total runtime, per-slide breakdown, and asset checklist with availability status.
+- **Export**: video configuration controls bound to frontmatter.
+- **Presentation Settings**: preset gallery with font/color/animation controls that keep markdown frontmatter in sync.
+
+---
+
+## Documentation
+
+- MARKDOWN_VIDEO_PLAN: [English](docs/EN/MARKDOWN_VIDEO_PLAN.md) / [ไทย](docs/TH/MARKDOWN_VIDEO_PLAN.md) – Roadmap covering presentation presets, safe zones, and native exporter milestones.
+- CHANGELOG: [English](docs/EN/CHANGELOG.md) / [ไทย](docs/TH/CHANGELOG.md) – Release history and upcoming feature checkpoints.
+- CONTRIBUTING: [English](docs/EN/CONTRIBUTING.md) / [ไทย](docs/TH/CONTRIBUTING.md) – Contribution workflow, coding standards, and review expectations.
+- CODE_OF_CONDUCT: [English](docs/EN/CODE_OF_CONDUCT.md) / [ไทย](docs/TH/CODE_OF_CONDUCT.md) – Community guidelines for respectful collaboration.
+
+---
+
+## Project Structure
+
+- [.gitignore](.gitignore)
+- [.npmignore](.npmignore)
+- [LICENSE](LICENSE)
+- [SECURITY.md](SECURITY.md)
+- [package.json](package.json)
+- [package-lock.json](package-lock.json)
+- [npm-runner.bat](npm-runner.bat)
+- [assets/](assets/)
+   - [fonts/](assets/fonts/)
+      - [fonts.css](assets/fonts/fonts.css)
+      - [README.md](assets/fonts/README.md)
+   - [icons/](assets/icons/)
+      - [icon.ico](assets/icons/icon.ico)
+      - [icon.jpg](assets/icons/icon.jpg)
+      - [icon.png](assets/icons/icon.png)
+      - [icon.webp](assets/icons/icon.webp)
+   - [image/](assets/image/)
+      - [chahuadev-markdown-presenter.png](assets/image/chahuadev-markdown-presenter.png)
+- [docs/](docs/)
+   - [EN/](docs/EN/)
+      - [CHANGELOG.md](docs/EN/CHANGELOG.md)
+      - [CODE_OF_CONDUCT.md](docs/EN/CODE_OF_CONDUCT.md)
+      - [CONTRIBUTING.md](docs/EN/CONTRIBUTING.md)
+      - [LICENSE](docs/EN/LICENSE)
+      - [MARKDOWN_VIDEO_PLAN.md](docs/EN/MARKDOWN_VIDEO_PLAN.md)
+      - [SECURITY.md](docs/EN/SECURITY.md)
+   - [TH/](docs/TH/)
+      - [CHANGELOG.md](docs/TH/CHANGELOG.md)
+      - [CODE_OF_CONDUCT.md](docs/TH/CODE_OF_CONDUCT.md)
+      - [CONTRIBUTING.md](docs/TH/CONTRIBUTING.md)
+      - [LICENSE](docs/TH/LICENSE)
+      - [MARKDOWN_VIDEO_PLAN.md](docs/TH/MARKDOWN_VIDEO_PLAN.md)
+      - [SECURITY.md](docs/TH/SECURITY.md)
+- [src/](src/)
+   - [README.md](src/README.md)
+   - [main/](src/main/)
+      - [README.md](src/main/README.md)
+      - [main.js](src/main/main.js)
+      - [preload.cjs](src/main/preload.cjs)
+      - [preload.js](src/main/preload.js)
+      - [preload.mjs](src/main/preload.mjs)
+   - [renderer/](src/renderer/)
+      - [index.html](src/renderer/index.html)
+      - [css/](src/renderer/css/)
+         - [style.css](src/renderer/css/style.css)
+      - [js/](src/renderer/js/)
+         - [app.js](src/renderer/js/app.js)
+         - [presentation-config.js](src/renderer/js/presentation-config.js)
+         - [templates.js](src/renderer/js/templates.js)
+         - [video-renderer.js](src/renderer/js/video-renderer.js)
+      - [vendor/](src/renderer/vendor/)
+         - [tailwind.js](src/renderer/vendor/tailwind.js)
+   - [shared/](src/shared/)
+      - [README.md](src/shared/README.md)
+      - [layout-schema.js](src/shared/layout-schema.js)
+      - [markdown-parser.js](src/shared/markdown-parser.js)
+      - [markdown-syntax.js](src/shared/markdown-syntax.js)
+      - [security-core.js](src/shared/security-core.js)
+      - [slide-paginator.js](src/shared/slide-paginator.js)
+      - [slide-renderer.js](src/shared/slide-renderer.js)
+- [workspace/](workspace/)
+   - [.gitkeep](workspace/.gitkeep)
+- [README.md](README.md)
+- `node_modules/` – Installed dependencies (omitted from this list by design).
+
+---
+
+## Security Posture
+
+- `security-core.js` blocks path traversal, enforces extension and size limits, validates hashes, and rate-limits operations.
+- The **Security** button surfaces telemetry (operation count, uptime, cache stats, rate limit entries).
+- Renderer access to the filesystem and export locations flows exclusively through vetted IPC handlers.
+
+---
+
+## Development Notes
+
+- The legacy code-upload scene workflow has been retired; markdown is now the authoritative input.
+- `src/renderer/js/app.js` and `src/shared/markdown-parser.js` are under active development—follow progress in `docs/EN|TH/MARKDOWN_VIDEO_PLAN.md` under Immediate Sprint Focus.
+- `src/renderer/js/presentation-config.js` unifies preset management while `templates.js` remains only for backwards compatibility.
+- **Current export method**: Native WebM recording using Canvas API + MediaRecorder (no external dependencies).
+- **Upcoming milestones**: Enhanced timeline engine, schema validation with actionable diagnostics, and OS-native MP4/GIF exporters scoped in the roadmap documents.
+
+---
+
+## Contributing
+
+1. Fork the repository.
+2. Create a feature branch (`git checkout -b feature/markdown-parser-upgrade`).
+3. Update or add tests when touching the parser, renderer, or security layers.
+4. Submit a pull request summarising how your change advances the markdown-first roadmap.
+
+Please read the roadmap documents in `docs/EN` or `docs/TH` before proposing major architectural shifts.
+
+---
+
+## Credits & Contact
+
+Chahua Development Co., Ltd.
+
+- Website: [chahuadev.com](https://chahuadev.com)
+- Email: chahuadev@gmail.com
+- GitHub: [@chahuadev](https://github.com/chahuadev)
+
+Stars, feedback, and roadmap suggestions are always appreciated!
+
+---
+
+Transform markdown into motion.

assets/fonts/README.md

@@ -0,0 +1,46 @@
+# Fonts
+
+This folder contains font definitions for the application.
+
+## Font Strategy
+
+We use a **system font fallback** approach instead of hosting custom font files:
+
+### Primary Fonts (with fallbacks)
+- **Inter** → System UI fonts (-apple-system, Segoe UI, Roboto, etc.)
+- **Source Code Pro** → Monospace system fonts (SF Mono, Cascadia Code, Consolas, etc.)
+- **Orbitron** → Display system fonts (SF Pro Display, etc.)
+
+## Why System Fonts?
+
+- ✅ **Zero bandwidth** - No font files to download
+- ✅ **Instant loading** - Fonts already installed on user's system
+- ✅ **Native look** - Matches OS design language
+- ✅ **Offline-first** - Always available
+- ✅ **Smaller package size** - No font files in distribution
+
+## `fonts.css`
+
+The `fonts.css` file defines:
+1. Optional `@font-face` for custom fonts (if user has them installed)
+2. System font fallback chains for each font family
+3. CSS custom properties for easy usage
+
+## Adding Custom Fonts (Optional)
+
+If you want to bundle custom fonts:
+
+1. Download font files (`.woff2` recommended)
+2. Place them in this folder
+3. Update `fonts.css` with proper `@font-face` declarations:
+
+```css
+@font-face {
+  font-family: 'Inter';
+  src: url('./Inter-Regular.woff2') format('woff2');
+  font-weight: 400;
+  font-display: swap;
+}
+```
+
+**Note**: Current implementation uses system fonts only for optimal performance and offline capability.

assets/fonts/fonts.css

@@ -0,0 +1,137 @@
+/**
+ * Local Fonts - Self-hosted for offline capability
+ * Replaces Google Fonts CDN with system fonts fallback
+ */
+
+/* Inter - Primary UI Font */
+@font-face {
+  font-family: 'Inter';
+  font-style: normal;
+  font-weight: 300 800;
+  font-display: swap;
+  src: local('Inter'), local('Inter-Regular');
+}
+
+/* Source Code Pro - Monospace for code */
+@font-face {
+  font-family: 'Source Code Pro';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Source Code Pro'), local('SourceCodePro-Regular');
+}
+
+/* Roboto Mono - Alternative Monospace */
+@font-face {
+  font-family: 'Roboto Mono';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Roboto Mono'), local('RobotoMono-Regular');
+}
+
+/* Fira Code - Code Font with Ligatures */
+@font-face {
+  font-family: 'Fira Code';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Fira Code'), local('FiraCode-Regular');
+}
+
+/* Poppins - Rounded Sans-serif */
+@font-face {
+  font-family: 'Poppins';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Poppins'), local('Poppins-Regular');
+}
+
+/* Playfair Display - Elegant Serif */
+@font-face {
+  font-family: 'Playfair Display';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Playfair Display'), local('PlayfairDisplay-Regular');
+}
+
+/* Montserrat - Display Font */
+@font-face {
+  font-family: 'Montserrat';
+  font-style: normal;
+  font-weight: 400 800;
+  font-display: swap;
+  src: local('Montserrat'), local('Montserrat-Regular');
+}
+
+/* Space Grotesk - Futuristic Font */
+@font-face {
+  font-family: 'Space Grotesk';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Space Grotesk'), local('SpaceGrotesk-Regular');
+}
+
+/* Ubuntu - Technical Font */
+@font-face {
+  font-family: 'Ubuntu';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Ubuntu'), local('Ubuntu-Regular');
+}
+
+/* Lato - Professional Font */
+@font-face {
+  font-family: 'Lato';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('Lato'), local('Lato-Regular');
+}
+
+/* JetBrains Mono - Developer Font */
+@font-face {
+  font-family: 'JetBrains Mono';
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: local('JetBrains Mono'), local('JetBrainsMono-Regular');
+}
+
+/* Orbitron - Display/Header Font */
+@font-face {
+  font-family: 'Orbitron';
+  font-style: normal;
+  font-weight: 400 900;
+  font-display: swap;
+  src: local('Orbitron'), local('Orbitron-Regular');
+}
+
+/* Fallback to system fonts if custom fonts not available */
+:root {
+  --font-inter: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
+  --font-code: 'Source Code Pro', 'Fira Code', 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
+  --font-display: 'Orbitron', 'Montserrat', 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
+  --font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
+  --font-rounded: 'Poppins', 'Nunito', -apple-system, BlinkMacSystemFont, sans-serif;
+  --font-space: 'Space Grotesk', 'Orbitron', monospace;
+  --font-tech: 'Ubuntu', 'Roboto', sans-serif;
+  --font-corporate: 'Lato', 'Open Sans', sans-serif;
+}
+
+/* Apply fonts globally */
+body {
+  font-family: var(--font-inter);
+}
+
+code, pre, .font-mono {
+  font-family: var(--font-code);
+}
+
+h1, h2, h3, .font-display {
+  font-family: var(--font-display);
+}

docs/EN/CHANGELOG.md

@@ -0,0 +1,292 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Planned
+- Enhanced video export quality (1080p @ 5-10 Mbps)
+- Export progress tracking with per-slide updates
+- Resolution/FPS/quality configuration
+- Abort/cancel functionality for long renders
+- Unit tests for core modules
+- Custom chart renderer (Canvas-based)
+- Syntax highlighter using regex tokenization
+- Audio integration with Web Audio API
+
+## [1.0.0] - 2025-10-20
+
+### Added
+
+#### Core Features
+- **Markdown Parser** with full CommonMark + GFM support
+  - 50+ regex patterns for comprehensive syntax recognition
+  - YAML frontmatter parsing for configuration
+  - Duration calculation heuristics
+  - Asset reference extraction
+
+- **Auto-pagination System**
+  - Visual line calculation with content-specific weights
+  - Intelligent slide splitting (max 6 lines per slide)
+  - Smart block splitting for code, tables, blockquotes
+  - Balanced page distribution algorithm
+  - Continuation markers for split content
+
+- **Interactive Preview Controls**
+  - Click anywhere to pause/resume
+  - Keyboard shortcuts: Space, P (pause/resume), ESC (stop)
+  - Promise-based waiting mechanism
+  - Visual pause overlay with instructions
+
+- **Full Markdown Syntax Support**
+  - ATX headings (# to ######)
+  - Setext headings (underlines)
+  - Bold, italic, strikethrough
+  - Inline and fenced code blocks
+  - Unordered lists (-, *, +)
+  - Ordered lists and task lists
+  - Links and images
+  - Blockquotes
+  - Tables (GFM)
+  - Horizontal rules
+  - Inline HTML blocks
+
+- **Timeline Visualization**
+  - Per-slide timing display
+  - Pagination indicators ([1/2], [2/2])
+  - Line count display (e.g., "6 lines")
+  - Continuation indicators ("↪ continued", "continues →")
+  - Total duration calculation
+
+- **Video Export**
+  - Native WebM encoding using MediaRecorder API
+  - Canvas-based slide rendering
+  - Template support with YAML configuration
+  - Custom accent colors
+
+- **User Interface**
+  - Dark blue theme (#0a1628 background, #3b82f6 primary)
+  - Three-tab layout: Markdown, Timeline, Templates
+  - Real-time markdown synchronization
+  - Validation diagnostics with error messages
+  - Bidirectional template selection
+
+#### Documentation
+- Complete bilingual documentation (EN/TH)
+  - Markdown Syntax Guide
+  - Auto-pagination System Guide
+  - Preview Controls Guide
+  - Architecture Document
+  - Development Plan/Roadmap
+  - Troubleshooting Guide
+
+- Demo files
+  - `complete-syntax-demo.md` - 25 slides demonstrating all syntax
+  - `pagination-demo.md` - 20+ slides showing pagination
+
+#### Development
+- Modular architecture with ES Modules
+- Security-first file operations through `security-core.js`
+- Path validation and rate limiting
+- Electron 28.0.0 with context isolation
+- Tailwind CSS (local bundle)
+
+### Changed
+- Reduced `maxLinesPerSlide` from 8 to 6 for better readability
+- Updated visual line weights:
+  - H1: 2.5 lines (was 2)
+  - H2: 2 lines (was 1.5)
+  - Lists: 1.2 lines (was 1)
+  - Code: 1 line per line (was 0.8)
+  - Images: 4 lines (was 3)
+  - HTML: 3 lines (was 2)
+  - Tables: 2.5 + rows×0.8 (was 2 + rows×0.5)
+
+### Fixed
+- Slide overflow issues with long content
+- Code block splitting accuracy
+- Table pagination with headers
+- Blockquote continuation markers
+
+### Security
+- Implemented file path validation
+- Added rate limiting for file operations
+- Enabled Electron security best practices
+- Disabled Node integration in renderer process
+
+---
+
+# บันทึกการเปลี่ยนแปลง
+
+การเปลี่ยนแปลงที่สำคัญทั้งหมดของโปรเจกต์นี้จะบันทึกไว้ในไฟล์นี้
+
+รูปแบบอิงตาม [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+และโปรเจกต์นี้ปฏิบัติตาม [Semantic Versioning](https://semver.org/spec/v2.0.0.html)
+
+## [Unreleased]
+
+### Added
+- **Presentation Mode** - PowerPoint-style manual navigation
+  - Dedicated "Presentation Mode" button alongside main controls
+  - Forward/backward navigation buttons with left/right arrows
+  - Keyboard shortcuts: ← → for navigation, Space for next, Home/End for first/last, ESC to exit
+  - Live slide counter display (e.g., "1 / 15")
+  - Automatic button disable at first/last slide boundaries
+- **Fullscreen Support** - True fullscreen presentation experience
+  - Fullscreen button in top-right corner during presentation
+  - F key toggle for quick fullscreen access
+  - Proper fullscreen styling (borderless, full viewport)
+  - Exit fullscreen on ESC or presentation mode exit
+- **Enhanced Navigation Controls**
+  - Semi-transparent navigation overlay at bottom center
+  - Circular prev/next buttons with hover effects and glow
+  - Backdrop blur for better readability over slide content
+  - Z-index layering for proper overlay stacking
+- **Application Reset Function**
+  - "Reset" button to return app to initial state
+  - Clears all markdown content, slides, and timeline
+  - Resets all settings to defaults (template, video config, theme)
+  - Confirmation dialog prevents accidental resets
+  - Automatically stops any active playback or presentation
+  - Restores default intro/outro content and timeline preview
+- **Programmer's PowerPoint - Code Editor Themes**
+  - 4 new professional code editor themes: Monokai, Solarized, SynthWave '84, Dracula
+  - Full syntax highlighting with theme-specific colors (keyword, string, number, comment, function, variable)
+  - Enhanced content styles with gradient text, glows, and shadows
+  - Styled blockquotes with large quote marks and inset shadows
+  - Code blocks with top gradient borders and hover animations
+- **Advanced Slide Transitions**
+  - **Glitch**: Digital glitch effect with random hue rotation
+  - **Matrix**: Digital rain simulation effect
+  - **Cube**: 3D cube rotation with perspective
+  - **Pixelate**: Blur-based pixelation transition
+- **CSS Animations Library**
+  - Matrix scrolling background animation
+  - Glitch skew effect for digital aesthetics
+  - Pixelate in/out animations
+  - Code block hover glow effect
+  - Heading text pulsing glow
+
+### วางแผนไว้
+- ปรับปรุงคุณภาพการเอ็กซ์พอร์ตวิดีโอ (1080p @ 5-10 Mbps)
+- ติดตามความคืบหน้าการเอ็กซ์พอร์ตพร้อมอัปเดตต่อสไลด์
+- การตั้งค่าความละเอียด/FPS/คุณภาพ
+- ฟังก์ชันยกเลิก/หยุดสำหรับการเรนเดอร์ยาว
+- Unit tests สำหรับโมดูลหลัก
+- ตัวเรนเดอร์กราฟแบบกำหนดเอง (Canvas-based)
+- Syntax highlighter ใช้ regex tokenization
+- การผสานเสียงด้วย Web Audio API
+
+---
+
+# บันทึกการเปลี่ยนแปลง (ต่อ - ภาษาไทย)
+
+## [Unreleased]
+
+### เพิ่ม
+- **โหมดนำเสนอ (Presentation Mode)** - การนำทางแบบกำหนดเองเหมือน PowerPoint
+  - ปุ่ม "Presentation Mode" เฉพาะข้างปุ่มควบคุมหลัก
+  - ปุ่มนำทางเดินหน้า/ถอยหลังพร้อมลูกศรซ้าย/ขวา
+  - ปุ่มลัด: ← → สำหรับนำทาง, Space สำหรับถัดไป, Home/End สำหรับแรก/สุดท้าย, ESC เพื่อออก
+  - แสดงตัวนับสไลด์แบบสด (เช่น "1 / 15")
+  - ปิดการใช้งานปุ่มอัตโนมัติที่ขอบเขตสไลด์แรก/สุดท้าย
+- **รองรับเต็มจอ (Fullscreen)** - ประสบการณ์นำเสนอแบบเต็มจอจริง
+  - ปุ่มเต็มจอที่มุมบนขวาขณะนำเสนอ
+  - กด F สลับเข้าเต็มจอได้ทันที
+  - สไตล์เต็มจอที่เหมาะสม (ไร้กรอบ, viewport เต็ม)
+  - ออกจากเต็มจอเมื่อกด ESC หรือออกจากโหมดนำเสนอ
+- **ควบคุมนำทางที่ปรับปรุง**
+  - Overlay นำทางกึ่งโปร่งใสที่ด้านล่างกลาง
+  - ปุ่มวงกลม prev/next พร้อม hover effects และแสง
+  - Backdrop blur เพื่อการอ่านที่ดีขึ้นเหนือเนื้อหาสไลด์
+  - การจัดเรียง Z-index สำหรับ overlay stacking ที่เหมาะสม
+- **ฟังก์ชันรีเซ็ตแอปพลิเคชัน**
+  - ปุ่ม "Reset" เพื่อนำแอปกลับสู่สถานะเริ่มต้น
+  - ล้างเนื้อหา markdown, สไลด์ และไทม์ไลน์ทั้งหมด
+  - รีเซ็ตการตั้งค่าทั้งหมดเป็นค่าเริ่มต้น (template, video config, theme)
+  - กล่องยืนยันป้องกันการรีเซ็ตโดยไม่ตั้งใจ
+  - หยุดการเล่นหรือนำเสนอที่ใช้งานอยู่อัตโนมัติ
+  - คืนค่าเนื้อหา intro/outro และพรีวิวไทม์ไลน์เริ่มต้น
+- **PowerPoint สำหรับโปรแกรมเมอร์ - Code Editor Themes**
+  - เทมเพลต code editor 4 แบบใหม่: Monokai, Solarized, SynthWave '84, Dracula
+  - Syntax highlighting เต็มรูปแบบพร้อมสีเฉพาะ theme (keyword, string, number, comment, function, variable)
+  - Content styles ที่ปรับปรุงพร้อม gradient text, เรือง และเงา
+  - Blockquotes มีสไตล์พร้อมเครื่องหมายคำพูดขนาดใหญ่และ inset shadows
+  - Code blocks พร้อม gradient borders ด้านบนและแอนิเมชัน hover
+- **Slide Transitions ขั้นสูง**
+  - **Glitch**: เอฟเฟกต์ glitch แบบดิจิทัลพร้อม hue rotation แบบสุ่ม
+  - **Matrix**: เอฟเฟกต์จำลอง digital rain
+  - **Cube**: การหมุนแบบ cube 3D พร้อม perspective
+  - **Pixelate**: Transition แบบ pixelation ใช้ blur
+- **ไลบรารี CSS Animations**
+  - แอนิเมชันพื้นหลัง Matrix scrolling
+  - เอฟเฟกต์ glitch skew สำหรับสุนทรียศาสตร์ดิจิทัล
+  - แอนิเมชัน pixelate in/out
+  - เอฟเฟกต์เรืองแสงพร้อม hover ของ code block
+  - เอฟเฟกต์เรืองแสง pulsing ของ heading text
+
+## [1.0.0] - 2025-10-20
+
+### เพิ่ม
+
+#### ฟีเจอร์หลัก
+- **Markdown Parser** พร้อมรองรับ CommonMark + GFM เต็มรูปแบบ
+  - รูปแบบ regex 50+ แบบสำหรับการจดจำ syntax อย่างครอบคลุม
+  - การแยก YAML frontmatter สำหรับการตั้งค่า
+  - Heuristics การคำนวณระยะเวลา
+  - การแยกการอ้างอิง asset
+
+- **ระบบแบ่งหน้าอัตโนมัติ**
+  - การคำนวณบรรทัดแบบ visual พร้อมน้ำหนักเฉพาะเนื้อหา
+  - การแบ่งสไลด์อัจฉริยะ (สูงสุด 6 บรรทัดต่อสไลด์)
+  - การแบ่งบล็อกอัจฉริยะสำหรับ code, tables, blockquotes
+  - อัลกอริทึมกระจายหน้าแบบสมดุล
+  - เครื่องหมายต่อเนื่องสำหรับเนื้อหาที่แบ่ง
+
+- **การควบคุมพรีวิวแบบโต้ตอบ**
+  - คลิกที่ใดก็ได้เพื่อหยุด/เล่นต่อ
+  - ปุ่มลัด: Space, P (หยุด/เล่นต่อ), ESC (หยุด)
+  - กลไกการรอแบบ promise-based
+  - Overlay หยุดด้วยคำแนะนำ
+
+- **รองรับ Markdown Syntax เต็มรูปแบบ**
+  - ATX headings (# ถึง ######)
+  - Setext headings (ขีดเส้นใต้)
+  - ตัวหนา, ตัวเอียง, ขีดฆ่า
+  - โค้ดบล็อกแบบ inline และ fenced
+  - รายการไม่มีลำดับ (-, *, +)
+  - รายการมีลำดับและ task lists
+  - ลิงก์และรูปภาพ
+  - Blockquotes
+  - ตาราง (GFM)
+  - เส้นแนวนอน
+  - บล็อก HTML แบบ inline
+
+### เปลี่ยนแปลง
+- ลด `maxLinesPerSlide` จาก 8 เป็น 6 เพื่อให้อ่านง่ายขึ้น
+- อัปเดตน้ำหนักบรรทัดแบบ visual:
+  - H1: 2.5 บรรทัด (เดิม 2)
+  - H2: 2 บรรทัด (เดิม 1.5)
+  - Lists: 1.2 บรรทัด (เดิม 1)
+  - Code: 1 บรรทัดต่อบรรทัด (เดิม 0.8)
+  - Images: 4 บรรทัด (เดิม 3)
+  - HTML: 3 บรรทัด (เดิม 2)
+  - Tables: 2.5 + rows×0.8 (เดิม 2 + rows×0.5)
+
+### แก้ไข
+- ปัญหาสไลด์ล้นจอกับเนื้อหายาว
+- ความแม่นยำการแบ่ง code block
+- การแบ่งหน้าตารางพร้อม headers
+- เครื่องหมายต่อเนื่อง blockquote
+
+### ความปลอดภัย
+- ใช้งานการตรวจสอบ file path
+- เพิ่ม rate limiting สำหรับการดำเนินการไฟล์
+- เปิดใช้งานแนวทางปฏิบัติที่ดีที่สุดด้านความปลอดภัยของ Electron
+- ปิด Node integration ใน renderer process
+
+[Unreleased]: https://github.com/chahuadev/chahuadev-markdown-presenter/compare/v1.0.0...HEAD
+[1.0.0]: https://github.com/chahuadev/chahuadev-markdown-presenter/releases/tag/v1.0.0

docs/EN/CODE_OF_CONDUCT.md

@@ -0,0 +1,201 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, caste, color, religion, or sexual
+identity and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the overall
+  community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or advances of
+  any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email address,
+  without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+[INSERT CONTACT EMAIL].
+
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series of
+actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or permanent
+ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior, harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within the
+community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.1, available at
+[https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1].
+
+Community Impact Guidelines were inspired by
+[Mozilla's code of conduct enforcement ladder][Mozilla CoC].
+
+For answers to common questions about this code of conduct, see the FAQ at
+[https://www.contributor-covenant.org/faq][FAQ]. Translations are available at
+[https://www.contributor-covenant.org/translations][translations].
+
+[homepage]: https://www.contributor-covenant.org
+[v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html
+[Mozilla CoC]: https://github.com/mozilla/diversity
+[FAQ]: https://www.contributor-covenant.org/faq
+[translations]: https://www.contributor-covenant.org/translations
+
+---
+
+# จรรยาบรรณผู้มีส่วนร่วม
+
+## คำมั่นสัญญาของเรา
+
+เราในฐานะสมาชิก ผู้มีส่วนร่วม และผู้นำให้คำมั่นว่าจะทำให้การมีส่วนร่วมในชุมชนของเรา
+เป็นประสบการณ์ที่ปราศจากการคุกคามสำหรับทุกคน โดยไม่คำนึงถึงอายุ ขนาดร่างกาย
+ความพิการที่มองเห็นหรือมองไม่เห็น เชื้อชาติ ลักษณะทางเพศ อัตลักษณ์ทางเพศ
+และการแสดงออก ระดับประสบการณ์ การศึกษา สถานะทางเศรษฐกิจและสังคม
+สัญชาติ รูปลักษณ์ส่วนบุคคล เชื้อชาติ วรรณะ สีผิว ศาสนา หรืออัตลักษณ์
+และรสนิยมทางเพศ
+
+เราให้คำมั่นว่าจะปฏิบัติและโต้ตอบในลักษณะที่เอื้อต่อชุมชนที่เปิดกว้าง ต้อนรับ
+หลากหลาย ครอบคลุม และมีสุขภาพดี
+
+## มาตรฐานของเรา
+
+ตัวอย่างพฤติกรรมที่เอื้อต่อสภาพแวดล้อมเชิงบวกสำหรับชุมชนของเรารวมถึง:
+
+* แสดงความเห็นอกเห็นใจและความเมตตาต่อผู้อื่น
+* เคารพความคิดเห็น มุมมอง และประสบการณ์ที่แตกต่าง
+* ให้และยอมรับคำวิจารณ์เชิงสร้างสรรค์อย่างสง่างาม
+* รับผิดชอบและขอโทษผู้ที่ได้รับผลกระทบจากความผิดพลาดของเรา
+  และเรียนรู้จากประสบการณ์
+* มุ่งเน้นสิ่งที่ดีที่สุดไม่เพียงแค่สำหรับเราในฐานะบุคคล แต่สำหรับชุมชนโดยรวม
+
+ตัวอย่างพฤติกรรมที่ไม่สามารถยอมรับได้รวมถึง:
+
+* การใช้ภาษาหรือภาพที่มีเนื้อหาทางเพศ และความสนใจหรือความก้าวหน้าทางเพศ
+  ทุกรูปแบบ
+* การก่อกวน การแสดงความคิดเห็นที่ดูถูก และการโจมตีส่วนตัวหรือทางการเมือง
+* การคุกคามสาธารณะหรือส่วนตัว
+* เผยแพร่ข้อมูลส่วนตัวของผู้อื่น เช่น ที่อยู่ทางกายภาพหรืออีเมล
+  โดยไม่ได้รับอนุญาตอย่างชัดเจน
+* พฤติกรรมอื่น ๆ ที่อาจถือได้ว่าไม่เหมาะสมในสภาพแวดล้อมระดับมืออาชีพ
+
+## ความรับผิดชอบในการบังคับใช้
+
+ผู้นำชุมชนมีหน้าที่รับผิดชอบในการชี้แจงและบังคับใช้มาตรฐาน
+พฤติกรรมที่ยอมรับได้และจะดำเนินการแก้ไขที่เหมาะสมและยุติธรรม
+เพื่อตอบสนองต่อพฤติกรรมใดๆ ที่พวกเขาพิจารณาว่าไม่เหมาะสม คุกคาม ไม่สุภาพ
+หรือเป็นอันตราย
+
+ผู้นำชุมชนมีสิทธิ์และความรับผิดชอบในการลบ แก้ไข หรือปฏิเสธ
+ความคิดเห็น คอมมิต โค้ด การแก้ไข wiki ปัญหา และการมีส่วนร่วมอื่นๆ
+ที่ไม่สอดคล้องกับจรรยาบรรณนี้ และจะสื่อสารเหตุผลในการตัดสินใจดูแล
+เมื่อเหมาะสม
+
+## การบังคับใช้
+
+กรณีพฤติกรรมที่ไม่เหมาะสมสามารถรายงานไปยังผู้นำชุมชนที่รับผิดชอบการบังคับใช้ที่
+[INSERT CONTACT EMAIL]
+
+ข้อร้องเรียนทั้งหมดจะได้รับการตรวจสอบและสอบสวนอย่างรวดเร็วและยุติธรรม
+
+ผู้นำชุมชนทั้งหมดมีหน้าที่เคารพความเป็นส่วนตัวและความปลอดภัย
+ของผู้รายงานเหตุการณ์ใดๆ
+
+## การระบุแหล่งที่มา
+
+จรรยาบรรณนี้ดัดแปลงมาจาก [Contributor Covenant][homepage]
+เวอร์ชัน 2.1 มีอยู่ที่
+[https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1]
+
+[homepage]: https://www.contributor-covenant.org
+[v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html

docs/EN/CONTRIBUTING.md

@@ -0,0 +1,357 @@
+# Contributing to Chahuadev Markdown Presenter
+
+First off, thank you for considering contributing to Chahuadev Markdown Presenter! It's people like you that make this project such a great tool.
+
+[English](#english) | [ไทย](#thai)
+
+---
+
+## English
+
+### Code of Conduct
+
+This project and everyone participating in it is governed by our [Code of Conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code.
+
+### How Can I Contribute?
+
+#### Reporting Bugs
+
+Before creating bug reports, please check the [existing issues](https://github.com/chahuadev/chahuadev-markdown-presenter/issues) to avoid duplicates.
+
+**When you create a bug report, please include:**
+
+- **Clear title and description**
+- **Steps to reproduce** the issue
+- **Expected behavior** vs **actual behavior**
+- **Screenshots** if applicable
+- **Environment details**:
+  - OS version (Windows/macOS/Linux)
+  - Node.js version (`node --version`)
+  - Electron version
+  - Application version
+
+**Example bug report:**
+
+```markdown
+**Title:** Auto-pagination fails with code blocks over 10 lines
+
+**Description:**
+When a Markdown file contains a code block with more than 10 lines,
+the auto-pagination system crashes.
+
+**Steps to Reproduce:**
+1. Create a markdown file with a code block > 10 lines
+2. Click "Sync Markdown"
+3. Observe error in console
+
+**Expected:**
+Code block should be split across multiple slides
+
+**Actual:**
+Application crashes with TypeError
+
+**Environment:**
+- OS: Windows 11
+- Node: v18.16.0
+- Electron: 28.0.0
+```
+
+#### Suggesting Enhancements
+
+Enhancement suggestions are tracked as GitHub issues. When creating an enhancement suggestion:
+
+- **Use a clear and descriptive title**
+- **Provide detailed description** of the suggested enhancement
+- **Explain why this enhancement would be useful**
+- **List alternative solutions** you've considered
+
+#### Pull Requests
+
+**Process:**
+
+1. **Fork** the repository
+2. **Create a branch** from `main`:
+   ```bash
+   git checkout -b feature/your-feature-name
+   ```
+3. **Make your changes** with clear commit messages
+4. **Test thoroughly** - ensure all existing functionality works
+5. **Update documentation** if needed
+6. **Submit a pull request** with:
+   - Clear description of changes
+   - Reference to related issues
+   - Screenshots/GIFs for UI changes
+
+**Commit Message Guidelines:**
+
+```
+type(scope): subject
+
+body (optional)
+
+footer (optional)
+```
+
+**Types:**
+- `feat`: New feature
+- `fix`: Bug fix
+- `docs`: Documentation changes
+- `style`: Code style changes (formatting, semicolons, etc.)
+- `refactor`: Code refactoring
+- `test`: Adding or updating tests
+- `chore`: Maintenance tasks
+
+**Examples:**
+```
+feat(pagination): add configurable max lines per slide
+
+fix(parser): handle empty code blocks correctly
+
+docs(readme): update installation instructions
+```
+
+### Development Setup
+
+#### Prerequisites
+
+- Node.js 18.0.0+
+- npm 8.0.0+
+- Git
+
+#### Getting Started
+
+```bash
+# Clone your fork
+git clone https://github.com/YOUR_USERNAME/chahuadev-markdown-presenter.git
+
+# Navigate to directory
+cd chahuadev-markdown-presenter
+
+# Add upstream remote
+git remote add upstream https://github.com/chahuadev/chahuadev-markdown-presenter.git
+
+# Install dependencies
+npm install
+
+# Start development
+npm start
+```
+
+#### Project Structure
+
+```
+src/
+├── main/           # Electron main process
+├── renderer/       # UI and frontend logic
+└── shared/         # Shared modules (parser, paginator, etc.)
+```
+
+#### Key Files
+
+- **`src/shared/markdown-parser.js`** - Markdown parsing logic
+- **`src/shared/slide-paginator.js`** - Auto-pagination algorithm
+- **`src/renderer/js/app.js`** - Main application controller
+- **`src/renderer/js/video-renderer.js`** - Video export logic
+
+### Coding Standards
+
+#### JavaScript Style
+
+- Use **ES6+ features** (const/let, arrow functions, template literals)
+- Use **ES Modules** (`import`/`export`)
+- **2 spaces** for indentation
+- **Semicolons** required
+- **Single quotes** for strings (except template literals)
+
+#### Code Comments
+
+```javascript
+/**
+ * Calculate visual lines for a content item
+ * @param {Object} item - Content item with type and content
+ * @returns {number} Number of visual lines
+ */
+export function calculateVisualLines(item) {
+  // Implementation
+}
+```
+
+#### Error Handling
+
+```javascript
+try {
+  const result = await parseMarkdown(content);
+  return result;
+} catch (error) {
+  console.error('Failed to parse markdown:', error);
+  throw new Error(`Markdown parsing failed: ${error.message}`);
+}
+```
+
+### Testing
+
+```bash
+# Run tests (when implemented)
+npm test
+
+# Run linter
+npm run lint
+```
+
+**Test Guidelines:**
+- Write unit tests for new features
+- Ensure tests pass before submitting PR
+- Include test cases for edge cases
+
+### Documentation
+
+When adding new features:
+
+1. **Update relevant documentation** in `docs/`
+2. **Add examples** to demonstrate usage
+3. **Update README.md** if user-facing changes
+4. **Write bilingual docs** (EN + TH) when possible
+
+### Questions?
+
+- Open an issue with the `question` label
+- Join discussions in existing issues
+- Check [documentation](docs/) first
+
+---
+
+## Thai
+
+### จรรยาบรรณ
+
+โปรเจกต์นี้และทุกคนที่เข้าร่วมอยู่ภายใต้ [จรรยาบรรณ](CODE_OF_CONDUCT.md) ของเรา การเข้าร่วมหมายความว่าคุณยอมรับจรรยาบรรณนี้
+
+### ฉันสามารถมีส่วนร่วมได้อย่างไร?
+
+#### รายงานบั๊ก
+
+ก่อนสร้างรายงานบั๊ก โปรดตรวจสอบ [issues ที่มีอยู่](https://github.com/chahuadev/chahuadev-markdown-presenter/issues) เพื่อหลีกเลี่ยงการซ้ำซ้อน
+
+**เมื่อสร้างรายงานบั๊ก โปรดระบุ:**
+
+- **หัวข้อและคำอธิบายที่ชัดเจน**
+- **ขั้นตอนการทำซ้ำ** ปัญหา
+- **พฤติกรรมที่คาดหวัง** กับ **พฤติกรรมจริง**
+- **ภาพหน้าจอ** ถ้ามี
+- **รายละเอียดสภาพแวดล้อม**:
+  - เวอร์ชัน OS (Windows/macOS/Linux)
+  - เวอร์ชัน Node.js (`node --version`)
+  - เวอร์ชัน Electron
+  - เวอร์ชันแอปพลิเคชัน
+
+#### แนะนำการปรับปรุง
+
+การแนะนำการปรับปรุงจะถูกติดตามเป็น GitHub issues เมื่อสร้างข้อเสนอแนะ:
+
+- **ใช้หัวข้อที่ชัดเจนและอธิบายได้**
+- **ให้คำอธิบายโดยละเอียด** ของการปรับปรุงที่แนะนำ
+- **อธิบายว่าทำไมการปรับปรุงนี้มีประโยชน์**
+- **แสดงทางเลือกอื่น** ที่คุณพิจารณา
+
+#### Pull Requests
+
+**กระบวนการ:**
+
+1. **Fork** repository
+2. **สร้าง branch** จาก `main`:
+   ```bash
+   git checkout -b feature/ชื่อฟีเจอร์ของคุณ
+   ```
+3. **ทำการเปลี่ยนแปลง** พร้อม commit messages ที่ชัดเจน
+4. **ทดสอบอย่างละเอียด** - ตรวจสอบว่าฟังก์ชันทั้งหมดทำงาน
+5. **อัปเดตเอกสาร** ถ้าจำเป็น
+6. **ส่ง pull request** พร้อม:
+   - คำอธิบายการเปลี่ยนแปลงที่ชัดเจน
+   - อ้างอิงถึง issues ที่เกี่ยวข้อง
+   - ภาพหน้าจอ/GIFs สำหรับการเปลี่ยนแปลง UI
+
+**แนวทาง Commit Message:**
+
+```
+type(scope): เรื่อง
+
+เนื้อหา (ถ้ามี)
+
+footer (ถ้ามี)
+```
+
+**ประเภท:**
+- `feat`: ฟีเจอร์ใหม่
+- `fix`: แก้บั๊ก
+- `docs`: เปลี่ยนแปลงเอกสาร
+- `style`: เปลี่ยนสไตล์โค้ด (formatting, semicolons, ฯลฯ)
+- `refactor`: รีแฟกเตอร์โค้ด
+- `test`: เพิ่มหรืออัปเดตเทสต์
+- `chore`: งานบำรุงรักษา
+
+### การตั้งค่าการพัฒนา
+
+#### ความต้องการเบื้องต้น
+
+- Node.js 18.0.0+
+- npm 8.0.0+
+- Git
+
+#### เริ่มต้น
+
+```bash
+# โคลน fork ของคุณ
+git clone https://github.com/YOUR_USERNAME/chahuadev-markdown-presenter.git
+
+# เข้าไปในโฟลเดอร์
+cd chahuadev-markdown-presenter
+
+# เพิ่ม upstream remote
+git remote add upstream https://github.com/chahuadev/chahuadev-markdown-presenter.git
+
+# ติดตั้ง dependencies
+npm install
+
+# เริ่มพัฒนา
+npm start
+```
+
+### มาตรฐานการเขียนโค้ด
+
+#### JavaScript Style
+
+- ใช้ **คุณสมบัติ ES6+** (const/let, arrow functions, template literals)
+- ใช้ **ES Modules** (`import`/`export`)
+- **2 spaces** สำหรับ indentation
+- **Semicolons** จำเป็น
+- **Single quotes** สำหรับ strings (ยกเว้น template literals)
+
+### การทดสอบ
+
+```bash
+# รันเทสต์ (เมื่อถูกสร้าง)
+npm test
+
+# รัน linter
+npm run lint
+```
+
+### เอกสาร
+
+เมื่อเพิ่มฟีเจอร์ใหม่:
+
+1. **อัปเดตเอกสารที่เกี่ยวข้อง** ใน `docs/`
+2. **เพิ่มตัวอย่าง** เพื่อแสดงการใช้งาน
+3. **อัปเดต README.md** ถ้ามีการเปลี่ยนแปลงที่ผู้ใช้เห็น
+4. **เขียนเอกสารสองภาษา** (EN + TH) เมื่อเป็นไปได้
+
+### มีคำถาม?
+
+- เปิด issue พร้อมป้ายกำกับ `question`
+- เข้าร่วมการสนทนาใน issues ที่มีอยู่
+- ตรวจสอบ [เอกสาร](docs/) ก่อน
+
+---
+
+Thank you for contributing! 🎉
+ขอบคุณสำหรับการมีส่วนร่วม! 🎉

docs/EN/LICENSE

@@ -0,0 +1,22 @@
+MIT License
+
+Copyright (c) 2025 Chahua Development Co., Ltd.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

docs/EN/MARKDOWN_VIDEO_PLAN.md

@@ -0,0 +1,534 @@
+
+# Markdown-to-Video Roadmap
+
+## Vision
+- **Markdown-to-Video Generator**: Write markdown, export video—powered entirely by native web technologies
+- **Markdown controls everything**: Content, timing, transitions, templates, and visual styling all defined in `.md` files
+- **Self-contained architecture**: Built on Electron + native Web APIs (Canvas, MediaRecorder, Web Audio, File System)
+- **Flexible slide creation**: Multiple slide break modes (`---` separators, `# H1` headers, `## H2` headers, or auto-detection)
+
+## Core Philosophy: Markdown as Video Source
+- **Input**: Markdown file with YAML frontmatter for video configuration
+- **Parser**: Custom `MarkdownParser` extracts slides, metadata, and asset references
+- **Renderer**: Canvas-based slide compositor using HTML/CSS → Canvas 2D API
+- **Encoder**: Native MediaRecorder API generates WebM video streams today, with planned OS-level pipelines (Media Foundation, AVFoundation, GStreamer) delivering MP4/GIF output without third-party libraries
+- **Export**: Files saved via secure IPC bridge with path validation
+
+## Guiding Principles
+- **Markdown-first workflow**: Deck authoring, timeline preview, and video export driven by `.md` source
+- **Native APIs only**: MediaRecorder (video encoding), Canvas 2D (rendering), Web Audio (future audio mixing)
+- **Preview = Export fidelity**: Same timeline engine powers live preview and final video output
+- **Security-first**: All file I/O flows through `security-core.js` with path validation and rate limiting
+- **Zero-config experience**: Sensible defaults with frontmatter-based overrides and shareable presentation presets
+
+## Completed Foundation
+- [x] Markdown-to-HTML pipeline in the Electron renderer.
+- [x] Baseline slide templates, theming, and live preview.
+- [x] Project structure separating main, renderer, and shared modules.
+- [x] Refactored renderer UI (`src/renderer/index.html`) into a markdown-first workflow with restored Templates tab.
+- [x] **Comprehensive Markdown Syntax Dictionary** (`markdown-syntax.js`) - 50+ patterns supporting CommonMark + GFM
+- [x] **Auto-pagination System** (`slide-paginator.js`) - Intelligent slide splitting based on visual line count (max 6 lines/slide)
+- [x] **Interactive Preview Controls** - Pause/resume with click, Space, P, ESC keyboard shortcuts
+- [x] **Dark Blue Theme** - Complete UI redesign with cohesive color scheme (#0a1628 background, #3b82f6 primary)
+
+## Immediate Sprint Focus (Current Work)
+
+### Phase 1: Core Functionality (COMPLETED)
+- [x] **Rebuild `src/renderer/js/app.js`** – Complete renderer controller:
+  - [x]  Parse markdown via `MarkdownParser` when user clicks "Sync Markdown"
+  - [x]   Extract frontmatter (template, video.*, theme.accent) and body content
+  - [x]   Generate slide array with auto-calculated durations based on content density
+  - [x]   Populate Timeline tab with per-slide timings, page indicators, line counts, and duration
+  - [x]   Update stage preview rendering with full markdown syntax support
+  - [x]   Apply selected template and accent color to CSS variables
+  - [x]   Enable Preview Timeline with pause/resume controls (click, Space, P, ESC)
+  - [x]   Full support for 15+ content types (H1-H6, lists, tables, blockquotes, code, HTML, etc.)
+  - [x]   Continuation markers for paginated slides ("↪ continued", "continues →")
+  - [x]   Page indicators in top-right corner of slides
+
+- [x] **Extend `src/shared/markdown-parser.js`** to:
+  - [x] Emit scene-level metadata including slide index, title, subtitle, and content items
+  - [x] Calculate per-slide durations using heuristics (H1=2s, list items=1s each, text=0.3s per word, code=0.5s per line)
+  - [x] Support frontmatter parsing for template ID, video settings, and custom metadata
+  - [x] Return asset references (images from `![alt](src)` syntax) for checklist validation
+  - [x] Provide `getSummary()` method returning totalSlides, paginatedSlides, estimatedDuration, and titles
+  - [x] **NEW: Integration with MarkdownSyntax dictionary** for comprehensive pattern recognition
+  - [x] **NEW: Auto-pagination support** with `enablePagination` and `maxLinesPerSlide` options
+  - [x] **NEW: Visual line tracking** - slides include `visualLines`, `totalPages`, `pageNumber` properties
+
+- [x] **Wire template selection bidirectionally**:
+  - [x] Clicking a template card in Templates tab updates `state.template`
+  - [x] Upsert `template: <id>` into markdown frontmatter via `upsertFrontmatterValue()`
+  - [x] Trigger `syncMarkdown()` to refresh timeline and reapply template CSS
+  - [x] Show active template name in "Active template:" hint label
+
+- [x] **Surface validation diagnostics**:
+  - [x] Show/hide `markdownDiagnostics` panel based on parse success/failure
+  - [x] Display human-friendly error messages (e.g., "Missing closing frontmatter delimiter", "Invalid slide structure")
+  - [x] Highlight unsynced state when editor content changes before next sync
+  - [x] Clear diagnostics automatically on successful sync
+
+### New Features Completed Beyond Original Scope
+
+#### 1. Comprehensive Markdown Syntax Dictionary (`src/shared/markdown-syntax.js`)
+- [x] **50+ regex patterns** covering CommonMark + GitHub Flavored Markdown
+- [x] **Block-level syntax**: ATX headings (# to ######), Setext headings (underlines), unordered lists (-, *, +), ordered lists, task lists, code blocks (fenced and indented), tables, blockquotes, horizontal rules, HTML blocks
+- [x] **Inline syntax**: bold (**text**), italic (*text*), strikethrough (~~text~~), inline code (`code`), links, images
+- [x] **Special syntax**: YAML frontmatter, footnotes, math blocks (LaTeX)
+- [x] **API**: `detectBlockType(line, nextLine)` and `parseInline(text)` methods
+- [x] **Documentation**: `MARKDOWN_SYNTAX.md` (EN/TH) with complete syntax reference
+
+#### 2. Auto-pagination System (`src/shared/slide-paginator.js`)
+**Status**:  **Needs Integration with Presentation Rendering** - Currently standalone, not yet used in actual rendering
+
+- [x] **Visual line calculation** with content-specific weights:
+  - H1 = 2.5 lines, H2 = 2 lines, H3-H6 = 1.5-1 lines
+  - List/blockquote items = 1.2 lines each
+  - Code blocks = 1 line per line (more readable)
+  - Tables = 2.5 (header) + rows × 0.8
+  - Images = 4 lines, HTML = 3 lines
+- [x] **Intelligent splitting algorithms**:
+  - Balanced page distribution (30% threshold)
+  - Smart block splitting for code, tables, blockquotes
+  - Atomic blocks (images, HTML, HR) never split
+  - Continuation markers automatically added
+- [x] **API**: `applyPagination(slides, config)` returns paginated slide array
+- [x] **Documentation**: `AUTO_PAGINATION.md` (EN/TH) with examples and algorithm details
+
+**Required Work**:
+- [ ] **Integrate with Smart Layout Engine**: Use line calculation logic with `ensureContentWithinBounds()`
+- [ ] **Integrate with Slide Renderer**: Make slides split automatically during actual rendering, not just parsing
+- [ ] **Configure via Presentation Settings**: Add `maxLinesPerSlide` to presentation-config.js
+- [ ] **Work with Safe Zones**: Calculate actual available space before splitting slides
+
+#### 3. Interactive Preview Controls
+- [x] **Pause/resume mechanism**:
+  - Click anywhere on preview stage to pause/resume (preview mode only)
+  - Keyboard shortcuts: Space or P to toggle, ESC to stop preview
+  - Promise-based waiting with 100ms polling for instant response
+
+#### 4. Presentation Mode (PowerPoint-style Navigation)
+- [x] **Manual slide navigation** with forward/back controls:
+  - "Presentation Mode" button alongside main controls
+  - Left/Right arrow buttons for navigation
+  - Keyboard shortcuts: ← → for prev/next, Space for next, Home/End for first/last
+  - Slide counter display (e.g., "1 / 15")
+  - ESC to exit presentation mode
+- [x] **Fullscreen support**:
+  - Fullscreen button in top-right corner during presentation
+  - F key toggle for fullscreen
+  - Proper fullscreen styling (borderless, full viewport)
+- [x] **Visual design**:
+  - Semi-transparent navigation controls at bottom center
+  - Circular prev/next buttons with hover effects
+  - Disabled state for first/last slide boundaries
+  - Backdrop blur for better readability
+
+#### 5. Application Reset Function
+- [x] **Reset Button** after Export Video
+  - Reset application to initial state
+  - Clear all markdown content and slides
+  - Reset all settings to defaults
+  - Confirmation dialog before execution
+  - Automatically stop playback or presentation
+  - Reset template to 'modern'
+  - Clear timeline and asset checklist
+
+#### 6. Programmer's PowerPoint - Code Editor Themes
+- [x] **New Code Editor Style Themes** in templates.js:
+  - **Monokai**: Classic theme with warm tones (magenta, green, cyan)
+  - **Solarized Dark**: Precision colors designed for readability
+  - **SynthWave '84**: Retro futuristic 80s aesthetic (hot pink, mint, yellow)
+  - **Dracula**: Dark theme for night coders
+  - Full syntax highlighting support with theme-specific colors
+- [x] **Enhanced Content Styles** in style.css:
+  - `.content-h1`: Gradient text with glow effect
+  - `.content-h2`: Border-left accent with text shadow
+  - `.content-blockquote`: Styled quote marks with inset shadow
+  - `.content-code-block`: Top gradient border with hover animation
+  - Syntax highlighting colors: keyword, string, number, comment, function, variable
+- [x] **Advanced Transitions** in slide-renderer.js:
+  - **Glitch**: Digital glitch effect with random offsets and hue rotation
+  - **Matrix**: Digital rain effect simulation
+  - **Cube**: 3D cube rotation transition
+  - **Pixelate**: Blur-based pixelation effect
+- [x] **CSS Animations**:
+  - `@keyframes matrixScroll`: Scrolling matrix effect
+  - `@keyframes glitchSkew`: Skew animation for glitch
+  - `@keyframes pixelateIn`: Blur in animation
+  - `@keyframes codeHighlight`: Code block hover glow
+  - `@keyframes textGlow`: Heading pulsing glow effect
+- [x] **Visual feedback**:
+  - Pause overlay with semi-transparent backdrop (blur 8px)
+  - Large pause icon with pulse animation
+  - Instructions: "Paused" text + keyboard hints
+  - Z-index 1000 for always-on-top display
+- [x] **State management**:
+  - `isPaused` boolean flag
+  - `pauseResolve` function reference for promise resolution
+  - Cleanup on preview stop
+- [x] **Documentation**: `PREVIEW_CONTROLS.md` (EN/TH) with usage guide
+
+#### 7. Enhanced Timeline Visualization
+- [x] **Pagination indicators**: Show "[1/2]", "[2/2]" badges for multi-page slides
+- [x] **Line count display**: "8 lines", "5 lines" to show content density
+- [x] **Continuation indicators**: "↪ continued" for split content
+- [x] **Duration display**: Accurate timing per slide with total duration
+
+#### 8. Smart Layout Measurement & Safe Zones
+- [x] Introduced shared `SMART_SAFE_ZONE` heuristics and padding helpers to derive consistent insets for measurement and stage rendering
+- [x] Synced typography, screen-type classes, and scene structure between the hidden measurement stage and the live stage frame
+- [x] Reused measurement-stage results to auto-scale overflowing content while keeping metadata (`data-safe-*`) available for diagnostics
+- [x] Filtered preview carry-over to exclude heading blocks and rely on authored titles instead of synthetic "Slide N" labels
+
+#### 9. Presentation Configuration System (`src/renderer/js/presentation-config.js`)
+- [x] Replaced rigid template catalogue with flexible presentation settings presets (fonts, clamp sizes, colors, backgrounds, animations)
+- [x] Introduced configuration API (`getCurrentConfig`, `setConfig`, `updateConfigPart`, `loadPreset`, `resetConfig`) for fine-grained control
+- [x] Defined curated preset families (Default, Professional, Minimal, Creative) plus font/background/transition option catalogs
+- [x] Auto-applies presentation variables to CSS custom properties (fonts, font sizes, colors, safe spacing) without external libraries
+- [x] Supports JSON import/export for sharing configuration profiles across markdown decks
+- [x] **Typography & Layout Controls** - Complete document formatting system:
+  - [x] Font size controls (H1, H2, Body Text) with responsive clamp (min, base vw, max)
+  - [x] Line height adjustments (heading, body) for optimal readability
+  - [x] Paragraph spacing controls (before/after) in rem units
+  - [x] Heading spacing controls (before/after) for visual hierarchy
+  - [x] Indentation controls (first-line, blockquote) for document structure
+  - [x] List indent and text alignment options (left, center, right, justify)
+- [x] **UI & Visual Effects Configuration**:
+  - [x] Preview slide opacity control (0-1 range)
+  - [x] Pause overlay blur effect (px)
+  - [x] Navigation button border width (px)
+  - [x] Gradient backdrop effects (spread %, blur px)
+- [x] **Border & Accent Width Controls**:
+  - [x] Heading accent border width (H2 left border)
+  - [x] Blockquote border width (left accent line)
+  - [x] Image border width (frame around images)
+  - [x] Link underline thickness
+  - [x] Table border width (grid lines)
+  - [x] Horizontal rule (HR) border width
+- [x] **Single Source of Truth Architecture**:
+  - [x] All default values centralized in `CONFIG_PRESETS.default.config`
+  - [x] CSS variables dynamically applied via `applyConfigToDOM()`
+  - [x] Live preview with instant feedback on all changes
+  - [x] Bidirectional sync between UI controls and configuration
+  - [x] Frontmatter persistence (save/load all settings to markdown YAML)
+- [x] **Developer Experience**:
+  - [x] Zero hardcoded values in CSS or JavaScript
+  - [x] Maintainable: change one config value, updates everywhere
+  - [x] Extensible: easy to add new styling properties
+  - [x] Type-safe: clear property structure with fallback values
+
+### Demo Files Created
+- [x] `workspace/complete-syntax-demo.md` - 25 slides demonstrating all Markdown syntax patterns
+- [x] `workspace/pagination-demo.md` - 20+ slides showing auto-pagination with various content lengths
+
+## Latest Updates (October 2025)
+
+### 10. Mode Isolation System (Exclusive Mode Switching)
+**Problem Identified**: UI elements from different modes were overlapping and causing conflicts in display and functionality
+
+**Solution** - Built a comprehensive exclusive mode switching system:
+
+#### Mode Manager (`src/renderer/js/mode-manager.js`)
+- [x] **Singleton Pattern**: Created `ModeManager` class with single instance for entire app
+- [x] **3 Strictly Separated Modes**:
+  - **Intro Mode**: Initial screen with no systems active (static display only)
+  - **Presentation Mode**: Presentation mode with keyboard navigation + Smart Layout only
+  - **Editor Mode**: Edit mode with content editable + drag & drop + Safe Zone border only
+
+#### Robust Control System
+- [x] **System Flags Tracking**: Monitors active systems (smartLayout, dragDrop, contentEditable, safeZoneBorder, etc.)
+- [x] **UI Visibility Control**: 
+  - `hideAllModeUI()` - Hides all UI elements from all modes
+  - `showPresentationUI()` - Shows only navigation controls, exit button, fullscreen button, edit button
+  - `showEditorUI()` - Shows only save button, cancel button, exit button
+- [x] **Smart Layout Management**:
+  - Intro Mode: `detach()` observers completely
+  - Presentation Mode: `reattach()` observers for auto-adjustment
+  - Editor Mode: `detach()` observers to prevent resizing during editing
+- [x] **Mode Switching Flow**:
+  ```javascript
+  switchMode(newMode) {
+    1. shutdownMode(currentMode)  // Shutdown old mode completely
+    2. currentMode = newMode       // Change mode
+    3. setDisplayMode(newMode)     // Update config
+    4. activateMode(newMode)       // Activate new mode exclusively
+    5. dispatch 'modeChanged' event
+  }
+  ```
+
+#### Integration with Existing Systems
+- [x] **app.js Integration**:
+  - `init()`: Calls `switchToIntroMode()` instead of `setDisplayMode('intro')`
+  - `startPresentationMode()`: Calls `switchToPresentationMode()`
+  - `exitPresentationMode()`: Calls `switchToIntroMode()`
+  - Removed all manual UI show/hide logic (Mode Manager handles it)
+  
+- [x] **slide-editor.js Integration**:
+  - `enterEditMode()`: Calls `switchToEditorMode()`
+  - `exitEditMode()`: Calls `switchToPresentationMode()`
+  - `enterDragMode()`: Calls `switchToEditorMode()`
+  - `exitDragMode()`: Calls `switchToPresentationMode()`
+  - Removed manual Smart Layout detach/reattach (Mode Manager handles it)
+  - Removed manual Safe Zone show/hide (Mode Manager handles it)
+
+#### Smart Layout Protection
+- [x] **Guard in `ensureContentWithinBounds()`**:
+  ```javascript
+  function ensureContentWithinBounds() {
+    const modeManager = getModeManager();
+    if (modeManager && !modeManager.isSystemActive('smartLayout')) {
+      return; // Don't execute if Smart Layout is disabled
+    }
+    // ... continue with calculations
+  }
+  ```
+
+#### Results
+- [x] **No UI Overlap**: Each mode shows only its relevant UI elements
+- [x] **No Smart Layout Interference**: Auto-sizing only works in Presentation Mode
+- [x] **Safe Edit Mode**: Editing works without interference from other systems
+- [x] **Single Source of Control**: `ModeManager` is the only controller for all modes
+
+#### Documentation and Maintenance
+- [x] Created `docs/TH/MODE_ISOLATION_FIX.md` with detailed fix documentation
+- [x] Added code comments indicating "Mode Manager handles this - no manual control needed"
+- [x] Removed redundant code from app.js and slide-editor.js
+
+### Strict Separation of 3 Display Logic Systems
+
+### Complete Separation of Three Display Logic Systems
+**Principle**: Each display mode has completely separate logic and Safe Zone systems to prevent modifications in one area from breaking others.
+
+#### 1. Intro Scene System (Small Preview with UI Sidebar)
+- [x] **Purpose**: Display slide previews in a small area of the UI page with side control panels
+- [x] **Characteristics**:
+  - [x] Fixed screen size (1280x720 fallback)
+  - [x] Hard-coded Safe Zone optimized for small display area
+  - [x] No dynamic calculation needed due to fixed dimensions
+- [x] **Core Functions** (marked LOCKED - do not modify):
+  - [x] `getStagePreviewData()` - Extract slide preview data
+  - [x] `renderStagePreview()` - Render preview to DOM
+  - [x] `updateStagePreview()` - Update preview when slides change
+- [x] **Status**: Working perfectly - do not modify or link to other modes
+
+#### 2. Presentation Mode - Small Screen (Normal Size Presentation)
+- [x] **Purpose**: Presentation mode on standard screens (not fullscreen) at 1920x1080 or smaller
+- [x] **Characteristics**:
+  - [x] Supports navigation with arrow keys (← →)
+  - [x] Ratio-based Safe Zone calculation for standard screens
+  - [x] Safe boundaries approximately 8-9% of width/height
+- [x] **Color Zones**:
+  - [x] **Red Zone**: Area outside screen bounds - no content allowed
+  - [x] **Green Zone**: Safe area inside boundaries - content safe here
+- [x] **Calculation**:
+  - [x] No hard-coded pixels
+  - [x] Calculated from actual screen size ratio
+  - [x] Formula: `safeInset = screenDimension × SAFE_ZONE_RATIO`
+
+#### 3. Presentation Mode - Large Screen (Full Screen Large Display)
+- [x] **Purpose**: Fullscreen mode on large screens (2560x1440+) or projectors
+- [x] **Characteristics**:
+  - [x] Automatic fullscreen mode entry
+  - [x] Smart Layout Engine measures and optimizes content for available space
+  - [x] Wider Safe Zone to accommodate projector overscan
+- [x] **Color Zones** (stricter than small screens):
+  - [x] **Red Zone**: Danger area 10-15% from edge - absolutely no content
+  - [x] **Yellow Zone**: Warning area 5-10% - content may be cut on some projectors
+  - [x] **Green Zone**: Safe area 80% center - content displays confidently
+- [x] **Calculation**:
+  - [x] Dynamic calculation from actual screen size
+  - [x] Ratio adjusts based on screen type (normal/large/ultra)
+  - [x] Example formula:
+    ```
+    baseRatio = 0.08 (8%)
+    maxRatio = 0.16 (16%)
+    actualInset = clamp(screenSize × baseRatio, MIN_PIXELS, screenSize × maxRatio)
+    ```
+
+### Code Protection from Modifications
+- [x] Added warning comments to all Intro Scene related functions
+- [x] Used clear `@LOCKED` and `DO NOT MODIFY` tags
+- [x] Separated comments into large blocks with border lines (==== lines)
+- [x] Specified reasons and impacts of modifications in comments
+- [x] No emojis in comments (may cause encoding issues)
+
+### Smart Layout and Safe Zone System
+- [x] Separated Safe Zone constants for each mode
+- [x] Intro Scene uses hard-coded constants
+- [x] Presentation Mode will create separate calculation functions
+- [ ] Create `computePresentationSafeZone()` for presentation mode
+- [ ] Create `computeLargeScreenSafeZone()` for large screens
+- [ ] Test Safe Zone calculations on multiple screen sizes
+
+## Outstanding Work
+
+### Smart Layout Engine
+- [ ] **Integrate Auto-pagination with Smart Layout**:
+  - [ ] Use line calculation logic from `slide-paginator.js` with `ensureContentWithinBounds()`
+  - [ ] Make slides split automatically during actual rendering, not just parsing
+  - [ ] Calculate available space within Safe Zones before deciding to split pages
+  - [ ] Add `maxLinesPerSlide` configuration to presentation-config.js
+- [ ] Rebuild `layout-schema.js` with a durable LayoutNode model and accurate per-section metrics aggregation
+- [ ] Feed the layout tree into `renderSlideToStage` so DOM output follows block semantics instead of raw HTML
+- [ ] Extend the measurement stage to consume layout tree data and refactor line/column calculations
+- [ ] Add unit tests covering smart layout behaviours (observers, smart-list balancing, layout tree diffing)
+
+### Cross-module Coordination (Markdown → Layout → Renderer)
+- [ ] Author a `layout-contract.md` document defining the shared JSON schema for slides/sections/blocks/inlines plus diagnostics
+- [ ] Refine `markdown-syntax.js` so it exposes a single detection/tokenization API and stores the metadata the parser requires
+- [ ] Update `markdown-parser.js` to consume that metadata and emit content items ready to map directly into layout blocks (e.g., link, inline emphasis)
+- [ ] Extend `layout-schema.js` to cover additional block types (heading, link, rich inline text) with metrics the renderer can consume immediately
+- [ ] Rework `app.js` to render purely from the layout tree, return measurement/diagnostic updates into the tree, and surface state changes to the UI
+- [ ] Introduce a feedback loop (diagnostics channel) between measurement stage ↔ layout-schema ↔ markdown-parser so heuristics can adapt
+
+### Timeline & Metadata Model
+- [ ] Extend markdown frontmatter for per-slide timing, transitions, narration cues, and media assets.
+- [ ] Generate a shared timeline model (scenes, tracks, assets) for preview and export.
+- [ ] Implement validation with actionable errors for missing or invalid metadata.
+
+### Presentation Settings System (Template Replacement) - COMPLETED
+- [x] Replace template cards UI with configurable presentation presets powered by `presentation-config.js`
+- [x] Round-trip presentation settings to markdown frontmatter (fonts, colors, animation choices)
+- [x] Expose granular controls (font families, clamp ranges, backgrounds, borders, effects) with live preview updates
+- [x] Update parser/exporter to consume presentation settings instead of legacy template identifiers
+- [x] **Complete Word/Excel-style Document Formatting**:
+  - [x] 11 UI controls for styling properties (borders, effects, visual elements)
+  - [x] Typography controls (8 inputs for spacing, indentation, alignment)
+  - [x] Font size controls (9 inputs for H1, H2, Text with min/base/max)
+  - [x] Line height controls (2 inputs for heading and body)
+  - [x] All settings saved to frontmatter with `presentation.styles.*` namespace
+  - [x] Full English translation of all UI labels and preset descriptions
+
+### Phase 2: Enhanced Export (Next Priority)
+- [x] Browser preview consumes timeline model flawlessly with full markdown rendering
+- [ ] **Improve native WebM export quality**:
+  - [ ] Enhanced MediaRecorder API with frame-perfect timing control
+  - [ ] Quality/bitrate configuration options (target: 1080p at 5-10 Mbps)
+  - [ ] Progress reporting with per-slide render updates and percentage display
+  - [ ] Abort/cancel functionality for long renders
+- [ ] Add a render job manager handling queueing, progress reporting, and cancellations
+- [ ] Export progress modal with real-time preview thumbnails
+
+### Visual Enhancements
+- [ ] Support slide-specific background images/videos with aspect-ratio aware cropping.
+- [ ] Introduce a declarative animation DSL covering transitions, text motion, and keyframed positioning.
+- [ ] **Build custom components** (no external libraries):
+  - Chart renderer using Canvas 2D API
+  - Syntax highlighter using regex tokenization
+  - Component registry for extensible markdown → visual mappings
+
+### Audio & Narration (Future)
+- [ ] Support synchronized narration tracks sourced from audio files.
+- [ ] **Mix audio using native Web Audio API**:
+  - Build custom ducking algorithm for background music
+  - Synchronize audio with video timeline
+  - No external audio processing libraries
+- [ ] Add scenario tests validating audio/video sync quality.
+
+### Collaboration & Templates
+- [ ] Ship selectable markdown + CSS template packs within the UI.
+- [ ] Provide a shared asset workspace with versioned references.
+- [ ] Define naming conventions and folder layout for video-safe media assets.
+
+## Phased Implementation Plan
+
+### Phase 1 – Timeline Core (COMPLETED)
+- [x] Rebuild `app.js` to parse markdown and populate timeline UI
+- [x] Extend `markdown-parser.js` with frontmatter and duration heuristics
+- [x] Wire bidirectional template selection (UI ↔ frontmatter)
+- [x] Surface validation diagnostics in Markdown tab
+- [x] **BONUS**: Comprehensive Markdown Syntax Dictionary with 50+ patterns
+- [x] **BONUS**: Auto-pagination system with visual line calculation
+- [x] **BONUS**: Interactive preview controls (pause/resume, keyboard shortcuts)
+- [x] **BONUS**: Enhanced timeline visualization with pagination indicators and line metrics
+- [x] **BONUS**: Presentation mode with navigation controls and fullscreen support
+- [x] **BONUS**: Application reset workflow and safeguarded smart layout safe zones
+- [x] **BONUS**: Code editor themed styling plus advanced transitions/animations
+- [x] **BONUS**: Template-free presentation configuration system with shareable presets
+- [ ] Add unit tests for parsing, timing calculations, and error cases (deferred to Phase 2)
+
+### Phase 2 – Enhanced Video Export (Next Priority)
+- [ ] Improve MediaRecorder-based WebM export quality and frame timing (target: 1080p @ 5-10 Mbps)
+- [x] Implement native render progress tracking with per-slide updates and percentage display
+- [x] Add resolution/FPS/quality controls synced to frontmatter
+- [ ] Support abort/cancel during export with cleanup and partial file deletion
+- [ ] Export progress modal with live thumbnail preview
+- [ ] Unit tests for markdown-syntax.js, slide-paginator.js, pause/resume mechanism
+- [ ] Create integration tests for sample deck → video output
+
+#### Native OS Encoding Roadmap (Security-first, No Third-party Libraries)
+- [ ] Design shared frame extraction pipeline (HTML → RGBA buffers/PNG frames) compatible with all native encoders
+- [ ] Windows: implement a sealed Media Foundation bridge that writes H.264/AAC MP4 via sandboxed worker process
+- [ ] macOS: build an AVFoundation exporter (AVAssetWriter) for H.264/AAC MP4 with strict file-path validation
+- [ ] Linux: integrate system GStreamer/VA-API pipeline (`appsrc → x264enc → mp4mux`) executed under security-core supervision
+- [ ] Add GIF output using the same native pipelines (MF Transform, AVFoundation ImageDestination, or GStreamer gifenc)
+- [ ] Instrument security hooks (path allow-list, rate limits, checksum validation) for every native encoder invocation
+
+### Phase 3 – Audio Integration (Future)
+- [ ] Parse narration file references from slide metadata
+- [ ] Load and validate audio assets via secure IPC
+- [ ] Mix narration + background music using Web Audio API
+- [ ] Synchronize audio with video timeline during preview and export
+- [ ] Add waveform visualization in Timeline tab
+
+### Phase 4 – Visual Enhancements (Future)
+- [ ] Build custom chart renderer (Canvas-based, no libraries)
+- [ ] Implement syntax highlighter using regex tokenization
+- [ ] Support slide-specific background images/videos
+- [ ] Create declarative animation DSL for keyframe-based transitions
+- [ ] Add component registry for extensible markdown → visual mappings
+
+### Phase 5 – Stabilization & Polish (Future)
+- [ ] Performance profiling and asset caching optimization
+- [ ] Improve error messages with contextual fix suggestions
+- [ ] Documentation refresh with video tutorials
+- [ ] Ship sample markdown decks demonstrating all features
+
+## Architecture Impact
+- **[x] Extended `src/shared/markdown-parser.js`**: Emits timeline JSON with scene metadata, durations, asset references, pagination info
+- **[x] NEW `src/shared/markdown-syntax.js`**: Dictionary-based pattern library with 50+ regex patterns for all CommonMark + GFM syntax
+- **[x] NEW `src/shared/slide-paginator.js`**: Visual line calculation and intelligent slide splitting with content-aware algorithms
+- [ ] **New `src/shared/timeline-engine.js`**: Compose timeline model, calculate timecodes, manage playback state (future)
+- **[x] Updated `src/renderer/js/app.js`**: Consumes parsed markdown for preview with pause/resume, timeline population, full syntax rendering, 13 new DOM references for styling controls, frontmatter save/load for all styling properties
+- **[x] Enhanced `src/renderer/js/video-renderer.js`**: Canvas-based slide rendering with full markdown support (export ready, quality enhancement pending)
+- **[x] Secure asset workspace**: Standardized `workspace/` folder with demo files and emoji-cleaner.js
+- **[x] NEW `src/renderer/js/presentation-config.js`**: Centralised presentation settings engine replacing fixed templates with 30+ configurable properties, CSS variable system, and frontmatter integration
+- **[x] Enhanced `src/renderer/css/style.css`**: Converted all hardcoded values to CSS variables (23+ new variables), added `.slide-table`, `.slide-hr`, `.timeline-page-indicator` classes for consistent theming
+- **[x] Updated `src/renderer/index.html`**: Added 30+ new UI controls organized in 3 sections (UI Effects, Border Widths, Typography), full English translation, improved help text
+
+## Current Technology Stack (Updated)
+- **Electron 28.0.0**: Desktop application framework
+- **MediaRecorder API**: Native WebM video encoding (VP8/VP9 codec)
+- **Planned native encoders**: Windows Media Foundation, macOS AVFoundation, Linux GStreamer/VA-API (system-provided, no third-party libraries)
+- **Canvas 2D API**: Slide rendering from HTML/CSS → Canvas with full markdown syntax support
+- **Tailwind CSS (local - 407KB)**: UI styling loaded from `src/renderer/vendor/tailwind.js`
+- **Web Audio API** (future): Native audio mixing and ducking
+- **Custom Modules**:
+  - **MarkdownParser** (`src/shared/markdown-parser.js`) - Parser with frontmatter, duration heuristics, pagination integration
+  - **MarkdownSyntax** (`src/shared/markdown-syntax.js`) - Pattern dictionary with 50+ regex for CommonMark + GFM
+  - **SlidePaginator** (`src/shared/slide-paginator.js`) - Visual line calculation and intelligent splitting
+  - **VideoRenderer** (`src/renderer/js/video-renderer.js`) - Canvas-based slide rendering
+  - **PresentationConfig** (`src/renderer/js/presentation-config.js`) - Template-free configuration presets and runtime styling engine
+  - **SecurityCore** (`src/shared/security-core.js`) - Path validation and rate limiting for file operations
+
+## Quality Strategy
+- [ ] Unit tests for `markdown-syntax.js` (pattern detection, inline parsing)
+- [ ] Unit tests for `slide-paginator.js` (line calculation, splitting algorithms)
+- [ ] Unit tests for `markdown-parser.js` (parsing, frontmatter, duration calculation, pagination integration)
+- [ ] Integration tests for markdown → timeline → video workflow
+- [ ] Snapshot tests for rendered HTML structures
+- [ ] Manual QA checklist for export quality across resolutions/FPS
+- [ ] Error handling validation (missing files, invalid frontmatter, etc.)
+- [ ] Pause/resume mechanism tests (promise resolution, keyboard shortcuts)
+
+## Documentation & Adoption
+- [x] **Produce bilingual guides**: Created 6 comprehensive documentation files
+  - [x] `MARKDOWN_SYNTAX.md` (EN/TH) - Complete syntax reference with examples
+  - [x] `AUTO_PAGINATION.md` (EN/TH) - Pagination system guide with algorithms
+  - [x] `PREVIEW_CONTROLS.md` (EN/TH) - Interactive controls usage guide
+- [x] **Publish sample decks**: Created demo markdown files
+  - [x] `workspace/complete-syntax-demo.md` - 25 slides demonstrating all syntax patterns
+  - [x] `workspace/pagination-demo.md` - 20+ slides showing auto-pagination
+- [ ] Schedule user testing sessions and collect feedback for iterative refinement
+- [ ] Produce video tutorials for export workflows and troubleshooting

docs/EN/SECURITY.md

@@ -0,0 +1,74 @@
+# Security Policy
+
+## Supported Versions
+
+We release patches for security vulnerabilities. Which versions are eligible for receiving such patches depends on the CVSS v3.0 Rating:
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 1.0.x   | :white_check_mark: |
+| < 1.0   | :x:                |
+
+## Reporting a Vulnerability
+
+**Please do not report security vulnerabilities through public GitHub issues.**
+
+Instead, please report them via email to: **[INSERT SECURITY EMAIL]**
+
+You should receive a response within 48 hours. If for some reason you do not, please follow up via email to ensure we received your original message.
+
+Please include the following information (as much as you can provide) to help us better understand the nature and scope of the possible issue:
+
+* Type of issue (e.g. buffer overflow, SQL injection, cross-site scripting, etc.)
+* Full paths of source file(s) related to the manifestation of the issue
+* The location of the affected source code (tag/branch/commit or direct URL)
+* Any special configuration required to reproduce the issue
+* Step-by-step instructions to reproduce the issue
+* Proof-of-concept or exploit code (if possible)
+* Impact of the issue, including how an attacker might exploit the issue
+
+This information will help us triage your report more quickly.
+
+## Preferred Languages
+
+We prefer all communications to be in English or Thai.
+
+## Security Update Process
+
+1. **Report received** - We acknowledge receipt within 48 hours
+2. **Investigation** - We investigate and validate the vulnerability
+3. **Fix development** - We develop and test a fix
+4. **Security advisory** - We publish a security advisory if needed
+5. **Release** - We release a patched version
+6. **Disclosure** - We publicly disclose the vulnerability after the fix is released
+
+## Known Security Considerations
+
+### File System Access
+
+This application requires file system access to:
+- Read Markdown files
+- Write exported video files
+- Access workspace directory
+
+**Mitigations:**
+- All file operations go through `security-core.js` with path validation
+- Rate limiting prevents abuse
+- User consent required for file operations
+
+### Electron Security
+
+We follow Electron security best practices:
+- Context isolation enabled
+- Node integration disabled in renderer
+- Preload scripts for IPC communication
+- Content Security Policy enforced
+
+### Third-Party Dependencies
+
+We regularly:
+- Update dependencies to latest secure versions
+- Run `npm audit` to check for vulnerabilities
+- Review dependency licenses and security advisories
+
+---

docs/TH/CHANGELOG.md

@@ -0,0 +1,171 @@
+# บันทึกการเปลี่ยนแปลง
+
+การเปลี่ยนแปลงที่สำคัญทั้งหมดของโปรเจกต์นี้จะบันทึกไว้ในไฟล์นี้
+
+รูปแบบอิงตาม [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+และโปรเจกต์นี้ปฏิบัติตาม [Semantic Versioning](https://semver.org/spec/v2.0.0.html)
+
+## [Unreleased]
+
+### Added
+- **Presentation Mode** - PowerPoint-style manual navigation
+  - Dedicated "Presentation Mode" button alongside main controls
+  - Forward/backward navigation buttons with left/right arrows
+  - Keyboard shortcuts: ← → for navigation, Space for next, Home/End for first/last, ESC to exit
+  - Live slide counter display (e.g., "1 / 15")
+  - Automatic button disable at first/last slide boundaries
+- **Fullscreen Support** - True fullscreen presentation experience
+  - Fullscreen button in top-right corner during presentation
+  - F key toggle for quick fullscreen access
+  - Proper fullscreen styling (borderless, full viewport)
+  - Exit fullscreen on ESC or presentation mode exit
+- **Enhanced Navigation Controls**
+  - Semi-transparent navigation overlay at bottom center
+  - Circular prev/next buttons with hover effects and glow
+  - Backdrop blur for better readability over slide content
+  - Z-index layering for proper overlay stacking
+- **Application Reset Function**
+  - "Reset" button to return app to initial state
+  - Clears all markdown content, slides, and timeline
+  - Resets all settings to defaults (template, video config, theme)
+  - Confirmation dialog prevents accidental resets
+  - Automatically stops any active playback or presentation
+  - Restores default intro/outro content and timeline preview
+- **Programmer's PowerPoint - Code Editor Themes**
+  - 4 new professional code editor themes: Monokai, Solarized, SynthWave '84, Dracula
+  - Full syntax highlighting with theme-specific colors (keyword, string, number, comment, function, variable)
+  - Enhanced content styles with gradient text, glows, and shadows
+  - Styled blockquotes with large quote marks and inset shadows
+  - Code blocks with top gradient borders and hover animations
+- **Advanced Slide Transitions**
+  - **Glitch**: Digital glitch effect with random hue rotation
+  - **Matrix**: Digital rain simulation effect
+  - **Cube**: 3D cube rotation with perspective
+  - **Pixelate**: Blur-based pixelation transition
+- **CSS Animations Library**
+  - Matrix scrolling background animation
+  - Glitch skew effect for digital aesthetics
+  - Pixelate in/out animations
+  - Code block hover glow effect
+  - Heading text pulsing glow
+
+### วางแผนไว้
+- ปรับปรุงคุณภาพการเอ็กซ์พอร์ตวิดีโอ (1080p @ 5-10 Mbps)
+- ติดตามความคืบหน้าการเอ็กซ์พอร์ตพร้อมอัปเดตต่อสไลด์
+- การตั้งค่าความละเอียด/FPS/คุณภาพ
+- ฟังก์ชันยกเลิก/หยุดสำหรับการเรนเดอร์ยาว
+- Unit tests สำหรับโมดูลหลัก
+- ตัวเรนเดอร์กราฟแบบกำหนดเอง (Canvas-based)
+- Syntax highlighter ใช้ regex tokenization
+- การผสานเสียงด้วย Web Audio API
+
+---
+
+# บันทึกการเปลี่ยนแปลง (ต่อ - ภาษาไทย)
+
+## [Unreleased]
+
+### เพิ่ม
+- **โหมดนำเสนอ (Presentation Mode)** - การนำทางแบบกำหนดเองเหมือน PowerPoint
+  - ปุ่ม "Presentation Mode" เฉพาะข้างปุ่มควบคุมหลัก
+  - ปุ่มนำทางเดินหน้า/ถอยหลังพร้อมลูกศรซ้าย/ขวา
+  - ปุ่มลัด: ← → สำหรับนำทาง, Space สำหรับถัดไป, Home/End สำหรับแรก/สุดท้าย, ESC เพื่อออก
+  - แสดงตัวนับสไลด์แบบสด (เช่น "1 / 15")
+  - ปิดการใช้งานปุ่มอัตโนมัติที่ขอบเขตสไลด์แรก/สุดท้าย
+- **รองรับเต็มจอ (Fullscreen)** - ประสบการณ์นำเสนอแบบเต็มจอจริง
+  - ปุ่มเต็มจอที่มุมบนขวาขณะนำเสนอ
+  - กด F สลับเข้าเต็มจอได้ทันที
+  - สไตล์เต็มจอที่เหมาะสม (ไร้กรอบ, viewport เต็ม)
+  - ออกจากเต็มจอเมื่อกด ESC หรือออกจากโหมดนำเสนอ
+- **ควบคุมนำทางที่ปรับปรุง**
+  - Overlay นำทางกึ่งโปร่งใสที่ด้านล่างกลาง
+  - ปุ่มวงกลม prev/next พร้อม hover effects และแสง
+  - Backdrop blur เพื่อการอ่านที่ดีขึ้นเหนือเนื้อหาสไลด์
+  - การจัดเรียง Z-index สำหรับ overlay stacking ที่เหมาะสม
+- **ฟังก์ชันรีเซ็ตแอปพลิเคชัน**
+  - ปุ่ม "Reset" เพื่อนำแอปกลับสู่สถานะเริ่มต้น
+  - ล้างเนื้อหา markdown, สไลด์ และไทม์ไลน์ทั้งหมด
+  - รีเซ็ตการตั้งค่าทั้งหมดเป็นค่าเริ่มต้น (template, video config, theme)
+  - กล่องยืนยันป้องกันการรีเซ็ตโดยไม่ตั้งใจ
+  - หยุดการเล่นหรือนำเสนอที่ใช้งานอยู่อัตโนมัติ
+  - คืนค่าเนื้อหา intro/outro และพรีวิวไทม์ไลน์เริ่มต้น
+- **PowerPoint สำหรับโปรแกรมเมอร์ - Code Editor Themes**
+  - เทมเพลต code editor 4 แบบใหม่: Monokai, Solarized, SynthWave '84, Dracula
+  - Syntax highlighting เต็มรูปแบบพร้อมสีเฉพาะ theme (keyword, string, number, comment, function, variable)
+  - Content styles ที่ปรับปรุงพร้อม gradient text, เรือง และเงา
+  - Blockquotes มีสไตล์พร้อมเครื่องหมายคำพูดขนาดใหญ่และ inset shadows
+  - Code blocks พร้อม gradient borders ด้านบนและแอนิเมชัน hover
+- **Slide Transitions ขั้นสูง**
+  - **Glitch**: เอฟเฟกต์ glitch แบบดิจิทัลพร้อม hue rotation แบบสุ่ม
+  - **Matrix**: เอฟเฟกต์จำลอง digital rain
+  - **Cube**: การหมุนแบบ cube 3D พร้อม perspective
+  - **Pixelate**: Transition แบบ pixelation ใช้ blur
+- **ไลบรารี CSS Animations**
+  - แอนิเมชันพื้นหลัง Matrix scrolling
+  - เอฟเฟกต์ glitch skew สำหรับสุนทรียศาสตร์ดิจิทัล
+  - แอนิเมชัน pixelate in/out
+  - เอฟเฟกต์เรืองแสงพร้อม hover ของ code block
+  - เอฟเฟกต์เรืองแสง pulsing ของ heading text
+
+## [1.0.0] - 2025-10-20
+
+### เพิ่ม
+
+#### ฟีเจอร์หลัก
+- **Markdown Parser** พร้อมรองรับ CommonMark + GFM เต็มรูปแบบ
+  - รูปแบบ regex 50+ แบบสำหรับการจดจำ syntax อย่างครอบคลุม
+  - การแยก YAML frontmatter สำหรับการตั้งค่า
+  - Heuristics การคำนวณระยะเวลา
+  - การแยกการอ้างอิง asset
+
+- **ระบบแบ่งหน้าอัตโนมัติ**
+  - การคำนวณบรรทัดแบบ visual พร้อมน้ำหนักเฉพาะเนื้อหา
+  - การแบ่งสไลด์อัจฉริยะ (สูงสุด 6 บรรทัดต่อสไลด์)
+  - การแบ่งบล็อกอัจฉริยะสำหรับ code, tables, blockquotes
+  - อัลกอริทึมกระจายหน้าแบบสมดุล
+  - เครื่องหมายต่อเนื่องสำหรับเนื้อหาที่แบ่ง
+
+- **การควบคุมพรีวิวแบบโต้ตอบ**
+  - คลิกที่ใดก็ได้เพื่อหยุด/เล่นต่อ
+  - ปุ่มลัด: Space, P (หยุด/เล่นต่อ), ESC (หยุด)
+  - กลไกการรอแบบ promise-based
+  - Overlay หยุดด้วยคำแนะนำ
+
+- **รองรับ Markdown Syntax เต็มรูปแบบ**
+  - ATX headings (# ถึง ######)
+  - Setext headings (ขีดเส้นใต้)
+  - ตัวหนา, ตัวเอียง, ขีดฆ่า
+  - โค้ดบล็อกแบบ inline และ fenced
+  - รายการไม่มีลำดับ (-, *, +)
+  - รา��การมีลำดับและ task lists
+  - ลิงก์และรูปภาพ
+  - Blockquotes
+  - ตาราง (GFM)
+  - เส้นแนวนอน
+  - บล็อก HTML แบบ inline
+
+### เปลี่ยนแปลง
+- ลด `maxLinesPerSlide` จาก 8 เป็น 6 เพื่อให้อ่านง่ายขึ้น
+- อัปเดตน้ำหนักบรรทัดแบบ visual:
+  - H1: 2.5 บรรทัด (เดิม 2)
+  - H2: 2 บรรทัด (เดิม 1.5)
+  - Lists: 1.2 บรรทัด (เดิม 1)
+  - Code: 1 บรรทัดต่อบรรทัด (เดิม 0.8)
+  - Images: 4 บรรทัด (เดิม 3)
+  - HTML: 3 บรรทัด (เดิม 2)
+  - Tables: 2.5 + rows×0.8 (เดิม 2 + rows×0.5)
+
+### แก้ไข
+- ปัญหาสไลด์ล้นจอกับเนื้อหายาว
+- ความแม่นยำการแบ่ง code block
+- การแบ่งหน้าตารางพร้อม headers
+- เครื่องหมายต่อเนื่อง blockquote
+
+### ความปลอดภัย
+- ใช้งานการตรวจสอบ file path
+- เพิ่ม rate limiting สำหรับการดำเนินการไฟล์
+- เปิดใช้งานแนวทางปฏิบัติที่ดีที่สุดด้านความปลอดภัยของ Electron
+- ปิด Node integration ใน renderer process
+
+[Unreleased]: https://github.com/chahuadev/chahuadev-markdown-presenter/compare/v1.0.0...HEAD
+[1.0.0]: https://github.com/chahuadev/chahuadev-markdown-presenter/releases/tag/v1.0.0

docs/TH/CODE_OF_CONDUCT.md

@@ -0,0 +1,65 @@
+# จรรยาบรรณผู้มีส่วนร่วม
+
+## คำมั่นสัญญาของเรา
+
+เราในฐานะสมาชิก ผู้มีส่วนร่วม และผู้นำให้คำมั่นว่าจะทำให้การมีส่วนร่วมในชุมชนของเรา
+เป็นประสบการณ์ที่ปราศจากการคุกคามสำหรับทุกคน โดยไม่คำนึงถึงอายุ ขนาดร่างกาย
+ความพิการที่มองเห็นหรือมองไม่เห็น เชื้อชาติ ลักษณะทางเพศ อัตลักษณ์ทางเพศ
+และการแสดงออก ระดับประสบการณ์ การศึกษา สถานะทางเศรษฐกิจและสังคม
+สัญชาติ รูปลักษณ์ส่วนบุคคล เชื้อชาติ วรรณะ สีผิว ศาสนา หรืออัตลักษณ์
+และรสนิยมทางเพศ
+
+เราให้คำมั่นว่าจะปฏิบัติและโต้ตอบในลักษณะที่เอื้อต่อชุมชนที่เปิดกว้าง ต้อนรับ
+หลากหลาย ครอบคลุม และมีสุขภาพดี
+
+## มาตรฐานของเรา
+
+ตัวอย่างพฤติกรรมที่เอื้อต่อสภาพแวดล้อมเชิงบวกสำหรับชุมชนของเรารวมถึง:
+
+* แสดงความเห็นอกเห็นใจและความเมตตาต่อผู้อื่น
+* เคารพความคิดเห็น มุมมอง และประสบการณ์ที่แตกต่าง
+* ให้และยอมรับคำวิจารณ์เชิงสร้างสรรค์อย่างสง่างาม
+* รับผิดชอบและขอโทษผู้ที่ได้รับผลกระทบจากความผิดพลาดของเรา
+  และเรียนรู้จากประสบการณ์
+* มุ่งเน้นสิ่งที่ดีที่สุดไม่เพียงแค่สำหรับเราในฐานะบุคคล แต่สำหรับชุมชนโดยรวม
+
+ตัวอย่างพฤติกรรมที่ไม่สามารถยอมรับได้รวมถึง:
+
+* การใช้ภาษาหรือภาพที่มีเนื้อหาทางเพศ และความสนใจหรือความก้าวหน้าทางเพศ
+  ทุกรูปแบบ
+* การก่อกวน การแสดงความคิดเห็นที่ดูถูก และการโจมตีส่วนตัวหรือทางการเมือง
+* การคุกคามสาธารณะหรือส่วนตัว
+* เผยแพร่ข้อมูลส่วนตัวของผู้อื่น เช่น ที่อยู่ทางกายภาพหรืออีเมล
+  โดยไม่ได้รับอนุญาตอย่างชัดเจน
+* พฤติกรรมอื่น ๆ ที่อาจถือได้ว่าไม่เหมาะสมในสภาพแวดล้อมระดับมืออาชีพ
+
+## ความรับผิดชอบในการบังคับใช้
+
+ผู้นำชุมชนมีหน้าที่รับผิดชอบในการชี้แจงและบังคับใช้มาตรฐาน
+พฤติกรรมที่ยอมรับได้และจะดำเนินการแก้ไขที่เหมาะสมและยุติธรรม
+เพื่อตอบสนองต่อพฤติกรรมใดๆ ที่พวกเขาพิจารณาว่าไม่เหมาะสม คุกคาม ไม่สุภาพ
+หรือเป็นอันตราย
+
+ผู้นำชุมชนมีสิทธิ์และความรับผิดชอบในการลบ แก้ไข หรือปฏิเสธ
+ความคิดเห็น คอมมิต โค้ด การแก้ไข wiki ปัญหา และการมีส่วนร่วมอื่นๆ
+ที่ไม่สอดคล้องกับจรรยาบรรณนี้ และจะสื่อสารเหตุผลใ��การตัดสินใจดูแล
+เมื่อเหมาะสม
+
+## การบังคับใช้
+
+กรณีพฤติกรรมที่ไม่เหมาะสมสามารถรายงานไปยังผู้นำชุมชนที่รับผิดชอบการบังคับใช้ที่
+[INSERT CONTACT EMAIL]
+
+ข้อร้องเรียนทั้งหมดจะได้รับการตรวจสอบและสอบสวนอย่างรวดเร็วและยุติธรรม
+
+ผู้นำชุมชนทั้งหมดมีหน้าที่เคารพความเป็นส่วนตัวและความปลอดภัย
+ของผู้รายงานเหตุการณ์ใดๆ
+
+## การระบุแหล่งที่มา
+
+จรรยาบรรณนี้ดัดแปลงมาจาก [Contributor Covenant][homepage]
+เวอร์ชัน 2.1 มีอยู่ที่
+[https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1]
+
+[homepage]: https://www.contributor-covenant.org
+[v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html

docs/TH/CONTRIBUTING.md

@@ -0,0 +1,135 @@
+## Thai
+
+### จรรยาบรรณ
+
+โปรเจกต์นี้และทุกคนที่เข้าร่วมอยู่ภายใต้ [จรรยาบรรณ](CODE_OF_CONDUCT.md) ของเรา การเข้าร่วมหมายความว่าคุณยอมรับจรรยาบรรณนี้
+
+### ฉันสามารถมีส่วนร่วมได้อย่างไร?
+
+#### รายงานบั๊ก
+
+ก่อนสร้างรายงานบั๊ก โปรดตรวจสอบ [issues ที่มีอยู่](https://github.com/chahuadev/chahuadev-markdown-presenter/issues) เพื่อหลีกเลี่ยงการซ้ำซ้อน
+
+**เมื่อสร้างรายงานบั๊ก โปรดระบุ:**
+
+- **หัวข้อและคำอธิบายที่ชัดเจน**
+- **ขั้นตอนการทำซ้ำ** ปัญหา
+- **พฤติกรรมที่คาดหวัง** กับ **พฤติกรรมจริง**
+- **ภาพหน้าจอ** ถ้ามี
+- **รายละเอียดสภาพแวดล้อม**:
+  - เวอร์ชัน OS (Windows/macOS/Linux)
+  - เวอร์ชัน Node.js (`node --version`)
+  - เวอร์ชัน Electron
+  - เวอร์ชันแอปพลิเคชัน
+
+#### แนะนำการปรับปรุง
+
+การแนะนำการปรับปรุงจะถูกติดตามเป็น GitHub issues เมื่อสร้างข้อเสนอแนะ:
+
+- **ใช้หัวข้อที่ชัดเจนและอธิบายได้**
+- **ให้คำอธิบายโดยละเอียด** ของการปรับปรุงที่แนะนำ
+- **อธิบายว่าทำไมการปรับปรุงนี้มีประโยชน์**
+- **แสดงทางเลือกอื่น** ที่คุณพิจารณา
+
+#### Pull Requests
+
+**กระบวนการ:**
+
+1. **Fork** repository
+2. **สร้าง branch** จาก `main`:
+   ```bash
+   git checkout -b feature/ชื่อฟีเจอร์ของคุณ
+   ```
+3. **ทำการเปลี่ยนแปลง** พร้อม commit messages ที่ชัดเจน
+4. **ทดสอบอย่างละเอียด** - ตรวจสอบว่าฟังก์ชันทั้งหมดทำงาน
+5. **อัปเดตเอกสาร** ถ้าจำเป็น
+6. **ส่ง pull request** พร้อม:
+   - คำอธิบายการเปลี่ยนแปลงที่ชัดเจน
+   - อ้างอิงถึง issues ที่เกี่ยวข้อง
+   - ภาพหน้าจอ/GIFs สำหรับการเปลี่ยนแปลง UI
+
+**แนวทาง Commit Message:**
+
+```
+type(scope): เรื่อง
+
+เนื้อหา (ถ้ามี)
+
+footer (ถ้ามี)
+```
+
+**ประเภท:**
+- `feat`: ฟีเจอร์ใหม่
+- `fix`: แก้บั๊ก
+- `docs`: เปลี่ยนแปลงเอกสาร
+- `style`: เปลี่ยนสไตล์โค้ด (formatting, semicolons, ฯลฯ)
+- `refactor`: รีแฟกเตอร์โค้ด
+- `test`: เพิ่มหรืออัปเดตเทสต์
+- `chore`: งานบำรุงรักษา
+
+### การตั้งค่าการพัฒนา
+
+#### ความต้องการเบื้องต้น
+
+- Node.js 18.0.0+
+- npm 8.0.0+
+- Git
+
+#### เริ่มต้น
+
+```bash
+# โคลน fork ของคุณ
+git clone https://github.com/YOUR_USERNAME/chahuadev-markdown-presenter.git
+
+# เข้าไปในโฟลเดอร์
+cd chahuadev-markdown-presenter
+
+# เพิ่ม upstream remote
+git remote add upstream https://github.com/chahuadev/chahuadev-markdown-presenter.git
+
+# ติดตั้ง dependencies
+npm install
+
+# เริ่มพัฒนา
+npm start
+```
+
+### มาตรฐานการเขียนโค้ด
+
+#### JavaScript Style
+
+- ใช้ **คุณสมบัติ ES6+** (const/let, arrow functions, template literals)
+- ใช้ **ES Modules** (`import`/`export`)
+- **2 spaces** สำหรับ indentation
+- **Semicolons** จำเป็น
+- **Single quotes** สำหรับ strings (ยกเว้น template literals)
+
+### การทดสอบ
+
+```bash
+# รันเทสต์ (เมื่อถูกสร้าง)
+npm test
+
+# รัน linter
+npm run lint
+```
+
+### เอกสาร
+
+เมื่อเพิ่มฟีเจอร์ใหม่:
+
+1. **อัปเดตเอกสารที่เกี่ยวข้อง** ใน `docs/`
+2. **เพิ่มตัวอย่าง** เพื่อแสดงการใช้งาน
+3. **อัปเดต README.md** ถ้ามีการเปลี่ยนแปลงที่ผู้ใช้เห็น
+4. **เขียนเอกสารสองภาษา** (EN + TH) เมื่อเป็นไปได้
+
+### มีคำถาม?
+
+- เปิด issue พร้อมป้ายกำกับ `question`
+- เข้าร่วมการสนทนาใน issues ที่มีอยู่
+- ตรวจสอบ [เอกสาร](docs/) ก่อน
+
+---
+
+Thank you for contributing! 🎉
+ขอบคุณสำหรับการมีส่วนร่วม! 🎉

docs/TH/LICENSE

@@ -0,0 +1,17 @@
+ใบอนุญาต MIT
+
+ลิขสิทธิ์ (c) 2025 บริษัท ชาฮัว ดีเวลลอปเมนท์ จำกัด
+
+อนุญาตให้บุคคลใดก็ตามที่ได้รับสำเนาซอฟต์แวร์นี้และไฟล์เอกสารประกอบที่เกี่ยวข้อง ("ซอฟต์แวร์")
+ ใช้งานซอฟต์แวร์นี้ได้โดยไม่มีค่าใช้จ่ายใดๆ รวมถึงแต่ไม่จำกัดเพียงสิทธิ์ในการใช้ 
+ คัดลอก แก้ไข ผสาน เผยแพร่ แจกจ่าย อนุญาตให้ใช้สิทธิ์ช่วง และ/หรือขายสำเนาซอฟต์แวร์ 
+ และอนุญาตให้บุคคลที่ได้รับซอฟต์แวร์นี้ดำเนินการดังกล่าวได้ ภายใต้เงื่อนไขดังต่อไปนี้:
+
+ประกาศลิขสิทธิ์ข้างต้นและประกาศการอนุญาตนี้จะรวมอยู่ในสำเนาหรือส่วนสำคัญของซอฟต์แวร์ทั้งหมด
+
+ซอฟต์แวร์นี้ให้บริการ "ตามสภาพ" โดยไม่มีการรับประกันใดๆ ทั้งสิ้น ไม่ว่าโดยชัดแจ้งหรือโดยนัย 
+รวมถึงแต่ไม่จำกัดเพียงการรับประกันความสามารถในการขาย ความเหมาะสมสำหรับวัตถุประสงค์เฉพาะ 
+และการไม่ละเมิดสิทธิ์ ไม่ว่าในกรณีใด ผู้เขียนหรือผู้ถือลิขสิทธิ์จะไม่รับผิดชอบต่อการเรียกร้อง ความเสียหาย 
+หรือความรับผิดอื่นใด ไม่ว่าจะเป็นการฟ้องร้องตามสัญญา การละเมิด หรืออื่นใด ที่เกิดขึ้นจาก
+จาก หรือเกี่ยวข้องกับซอฟต์แวร์ หรือการใช้งานหรือการดำเนินการอื่นใดใน
+ซอฟต์แวร์

docs/TH/MARKDOWN_VIDEO_PLAN.md

@@ -0,0 +1,621 @@
+# แผนพัฒนา Markdown-to-Video
+
+## วิสัยทัศน์
+- **Markdown-to-Video Generator**: เขียน Markdown แล้วเอ็กซ์พอร์ตเป็นวิดีโอ—ใช้เทคโนโลยีเว็บดั้งเดิมทั้งหมด
+- **Markdown ควบคุมทุกอย่าง**: เนื้อหา เวลา ทรานซิชัน เทมเพลต และสไตล์ภาพกำหนดทั้งหมดในไฟล์ `.md`
+- **สถาปัตยกรรมแบบครบวงจร**: สร้างบน Electron + Web APIs ดั้งเดิม (Canvas, MediaRecorder, Web Audio, File System)
+
+## หลักการหลัก: Markdown คือแหล่งต้นทางวิดีโอ
+- **อินพุต**: ไฟล์ Markdown พร้อม YAML frontmatter สำหรับการตั้งค่าวิดีโอ
+- **ตัวแยกส่วน**: `MarkdownParser` แยกสไลด์ ข้อมูลเมทา และอ้างอิงแอสเซ็ต
+- **ตัวเรนเดอร์**: ตัวประกอบสไลด์บน Canvas จาก HTML/CSS → Canvas 2D API
+- **ตัวเข้ารหัส**: MediaRecorder API สร้างสตรีมวิดีโอ WebM (ปัจจุบัน) พร้อมแผนใช้ตัวเข้ารหัสระดับระบบปฏิบัติการ (Media Foundation, AVFoundation, GStreamer) เพื่อสร้าง MP4/GIF โดยไม่พึ่งไลบรารีภายนอก
+- **ตัวเอ็กซ์พอร์ต**: บันทึกไฟล์ผ่าน IPC bridge ที่มีการตรวจสอบความปลอดภัย
+
+## หลักการชี้นำ
+- **Workflow แบบ Markdown-first**: การเขียนเด็ค พรีวิวไทม์ไลน์ และเอ็กซ์พอร์ตวิดีโอขับเคลื่อนด้วยไฟล์ `.md`
+- **ใช้ Native APIs เท่านั้น**: MediaRecorder (เข้ารหัสวิดีโอ), Canvas 2D (เรนเดอร์), Web Audio (ผสมเสียงในอนาคต)
+- **พรีวิว = เอ็กซ์พอร์ต**: ไทม์ไลน์เอ็นจินเดียวกันขับเคลื่อนทั้งพรีวิวสดและเอาต์พุตสุดท้าย
+- **ความปลอดภัยสำคัญ**: การเข้าถึงไฟล์ทั้งหมดผ่าน `security-core.js` พร้อมตรวจสอบ path และจำกัดอัตรา
+- **ใช้งานได้ทันที**: ค่าเริ่มต้นที่เหมาะสมพร้อม preset การนำเสนอที่ปรับแต่ง/แชร์ผ่าน frontmatter ได้
+
+## งานที่ทำแล้ว
+- [x]  ระบบแปลง Markdown → HTML สำหรับ renderer ของ Electron
+- [x]  เทมเพลตพื้นฐาน การสลับธีม และพรีวิวแบบเรียลไทม์
+- [x]  ออกแบบโครงสร้างโปรเจกต์รองรับการแยก main/renderer/shared
+- [x]  รีแฟกเตอร์ UI renderer (`src/renderer/index.html`) ให้เป็น workflow แบบ Markdown-first พร้อมแท็บ Templates
+- [x]  **พจนานุกรม Markdown Syntax ครบถ้วน** (`markdown-syntax.js`) - รองรับ 50+ รูปแบบ CommonMark + GFM
+- [x]  **ระบบแบ่งหน้าอัตโนมัติ** (`slide-paginator.js`) - แบ่งสไลด์อัจฉริยะตามจำนวนบรรทัดแสดงผล (สูงสุด 6 บรรทัด/สไลด์)
+- [x]  **ควบคุมพรีวิวแบบโต้ตอบ** - หยุด/เล่นต่อด้วยคลิก, ปุ่ม Space, P, ESC
+- [x]  **ธีมสีน้ำเงินเข้ม** - UI ครบชุดสีที่สอดคล้องกัน (พื้นหลัง #0a1628, หลัก #3b82f6)
+
+## เฟส 1: ฟังก์ชันหลัก ([x]  เสร็จสมบูรณ์)
+
+### งานหลักที่เสร็จแล้ว
+- [x]  **เขียน `src/renderer/js/app.js` ใหม่** – Controller ครบถ้วน:
+  - [x]  แยก markdown ผ่าน `MarkdownParser` เมื่อคลิก "Sync Markdown"
+  - [x]  แยก frontmatter (template, video.*, theme.accent) และเนื้อหา
+  - [x]  สร้างอาร์เรย์สไลด์พร้อ��คำนวณเวลาอัตโนมัติตามความหนาแน่นเนื้อหา
+  - [x]  เติมข้อมูลแท็บ Timeline พร้อมเวลาต่อสไลด์, ตัวบ่งชี้หน้า, จำนวนบรรทัด, ระยะเวลา
+  - [x]  อัปเดตการเรนเดอร์พรีวิวเวทีพร้อมรองรับ markdown syntax เต็มรูปแบบ
+  - [x]  ใช้เทมเพลตและสีที่เลือกกับตัวแปร CSS
+  - [x]  เปิดใช้งาน Preview Timeline พร้อมควบคุมหยุด/เล่นต่อ (คลิก, Space, P, ESC)
+  - [x]  รองรับเนื้อหา 15+ ประเภท (H1-H6, lists, tables, blockquotes, code, HTML, ฯลฯ)
+  - [x]  เครื่องหมายต่อเนื่องสำหรับสไลด์ที่แบ่ง ("↪ continued", "continues →")
+  - [x]  ตัวบ่งชี้หน้าที่มุมบนขวาของสไลด์
+
+- [x]  **ขยาย `src/shared/markdown-parser.js`** เพื่อ:
+  - [x]  ปล่อยข้อมูลเมทาระดับฉาก รวมถึง index, title, subtitle, และ content items
+  - [x]  คำนวณระยะเวลาต่อสไลด์ใช้ heuristics (H1=2s, list=1s แต่ละรายการ, text=0.3s ต่อคำ, code=0.5s ต่อบรรทัด)
+  - [x]  รองรับการแยก frontmatter สำหรับ template ID, video settings, และข้อมูลเมทากำหนดเอง
+  - [x]  ส่งคืนการอ้างอิง asset (ภาพจาก `![alt](src)`) สำหรับตรวจสอบ checklist
+  - [x]  มีเมธอด `getSummary()` ส่งคืน totalSlides, paginatedSlides, estimatedDuration, และ titles
+  - [x]  **ใหม่: ผสานกับพจนานุกรม MarkdownSyntax** สำหรับจดจำรูปแบบอย่างครอบคลุม
+  - [x]  **ใหม่: รองรับแบ่งหน้าอัตโนมัติ** พร้อมตัวเลือก `enablePagination` และ `maxLinesPerSlide`
+  - [x]  **ใหม่: ติดตามบรรทัดแบบ visual** - สไลด์มี properties `visualLines`, `totalPages`, `pageNumber`
+
+- [x]  **ผูกการเลือกเทมเพลตแบบสองทาง**:
+  - [x]  คลิกการ์ดเทมเพลตในแท็บ Templates อัปเดต `state.template`
+  - [x]  Upsert `template: <id>` เข้า frontmatter ผ่าน `upsertFrontmatterValue()`
+  - [x]  เรียก `syncMarkdown()` เพื่อรีเฟรช timeline และใช้ CSS เทมเพลตใหม่
+  - [x]  แสดงชื่อเทมเพลตที่ใช้งานในฉลาก "Active template:"
+
+- [x]  **แสดงการวินิจฉัยความถูกต้อง**:
+  - [x]  แสดง/ซ่อนแผง `markdownDiagnostics` ตามความสำเร็จ/ล้มเหลวของการแยกส่วน
+  - [x]  แสดงข้อความผิดพลาดที่เป็นมิตร (เช่น "ไม่มี frontmatter delimiter ปิด", "โครงสร้างสไลด์ไม่ถูกต้อง")
+  - [x]  เน้นสถานะยังไม่ซิงก์เมื่อเนื้อหาเอดิเตอร์เปลี่ยนก่อนซิงก์ครั้งต่อไป
+  - [x]  ล้างการวินิจฉัยอัตโนมัติเมื่อซิงก์สำเร็จ
+
+### ฟีเจอร์ใหม่ที่เสร็จนอกเหนือจากแผนเดิม
+
+#### 1. พจนานุกรม Markdown Syntax ครบถ้วน (`src/shared/markdown-syntax.js`)
+- [x]  **รูปแบบ regex 50+ แบบ** ครอบคลุม CommonMark + GitHub Flavored Markdown
+- [x]  **Block-level syntax**: ATX headings (# ถึง ######), Setext headings (ขีดเส้นใต้), unordered lists (-, *, +), ordered lists, task lists, code blocks (fenced และ indented), tables, blockquotes, horizontal rules, HTML blocks
+- [x]  **Inline syntax**: bold (**text**), italic (*text*), strikethrough (~~text~~), inline code (`code`), links, images
+- [x]  **Special syntax**: YAML frontmatter, footnotes, math blocks (LaTeX)
+- [x]  **API**: เมธอด `detectBlockType(line, nextLine)` และ `parseInline(text)`
+- [x]  **เอกสาร**: `MARKDOWN_SYNTAX.md` (EN/TH) พร้อมคู่มือ syntax ครบถ้วน
+
+#### 2. ระบบแบ่งหน้าอัตโนมัติ (`src/shared/slide-paginator.js`)
+**สถานะ**:  **ต้องผสานเข้า Presentation Rendering** - ตอนนี้แยกออกมาต่างหาก ยังไม่ได้ใช้งานจริง
+
+- [x] **การคำนวณบรรทัดแบบ visual** พร้อมน้ำหนักเฉพาะเนื้อหา:
+  - H1 = 2.5 บรรทัด, H2 = 2 บรรทัด, H3-H6 = 1.5-1 บรรทัด
+  - List/blockquote items = 1.2 บรรทัดต่อรายการ
+  - Code blocks = 1 บรรทัดต่อบรรทัด (อ่านง่ายขึ้น)
+  - Tables = 2.5 (header) + rows × 0.8
+  - Images = 4 บรรทัด, HTML = 3 บรรทัด
+- [x] **อัลกอริทึมแบ่งอัจฉริยะ**:
+  - กระจายหน้าแบบสมดุล (threshold 30%)
+  - แบ่งบล็อกอัจฉริยะสำหรับ code, tables, blockquotes
+  - บล็อกแบบ atomic (images, HTML, HR) ไม่แบ่ง
+  - เครื่องหมายต่อเนื่องเพิ่มอัตโนมัติ
+- [x] **API**: `applyPagination(slides, config)` ส่งคืนอาร์เรย์สไลด์ที่แบ่งหน้าแล้ว
+- [x] **เอกสาร**: `AUTO_PAGINATION.md` (EN/TH) พร้อมตัวอย่างและรายละเอียดอัลกอริทึม
+
+**งานที่ต้องทำ**:
+- [ ] **ผสานเข้า Smart Layout Engine**: ใช้ logic การคำนวณบรรทัดร่วมกับ `ensureContentWithinBounds()`
+- [ ] **ผสานเข้า Slide Renderer**: ทำให้สไลด์แบ่งอัตโนมัติตอน render จริง ไม่ใช่แค่ตอน parse
+- [ ] **ตั้งค่าผ่าน Presentation Config**: เพิ่ม `maxLinesPerSlide` ลงใน presentation settings
+- [ ] **ใช้กับ Safe Zone**: คำนวณพื้นที่ว่างจริงก่อนแบ่งสไลด์
+
+#### 3. ควบคุมพรีวิวแบบโต้ตอบ
+- [x]  **กลไกหยุด/เล่นต่อ**:
+  - คลิกที่ใดก็ได้บนเวทีพรีวิวเพื่อหยุด/เล่นต่อ (โหมดพรีวิวเท่านั้น)
+  - ปุ่มลัด: Space หรือ P สลับ, ESC หยุดพรีวิว
+  - การรอแบบ promise-based พร้อม polling 100ms เพื่อตอบสนองทันที
+- [x]  **ฟีดแบ็กภาพ**:
+  - Overlay หยุดพร้อม backdrop กึ่งโปร่งใส (blur 8px)
+  - ไอคอนหยุดขนาดใหญ่ ⏸ พร้อมแอนิเมชัน pulse
+  - คำแนะนำ: ข้อความ "Paused" + คำใบ้ปุ่มลัด
+  - Z-index 1000 เพื่อแสดงบนสุดเสมอ
+- [x]  **การจัดการสถานะ**:
+  - แฟล็ก boolean `isPaused`
+  - ฟังก์ชันอ้างอิง `pauseResolve` สำหรับ promise resolution
+  - ทำความสะอาดเมื่อหยุดพรีวิว
+- [x]  **เอกสาร**: `PREVIEW_CONTROLS.md` (EN/TH) พร้อมคู่มือการใช้งาน
+
+#### 4. โหมดนำเสนอ (Presentation Mode) แบบ PowerPoint
+- [x]  **การนำทางสไลด์แบบกำหนดเอง** พร้อมควบคุมเดินหน้า/ถอยหลัง:
+  - ปุ่ม "Presentation Mode" ข้างปุ่มควบคุมหลัก
+  - ปุ่มลูกศร ← → สำหรับนำทางไปข้างหน้า/ข้างหลัง
+  - ปุ่มลัด: ← → สำหรับ prev/next, Space สำหรับ next, Home/End สำหรับ first/last
+  - แสดงตัวนับสไลด์ (เช่น "1 / 15")
+  - ESC เพื่อออกจากโหมดนำเสนอ
+- [x]  **รองรับเต็มจอ (Fullscreen)**:
+  - ปุ่มเต็มจอที่มุมบนขวาขณะนำเสนอ
+  - กด F สลับเต็มจอ
+  - สไตล์เต็มจอที่เหมาะสม (ไร้กรอบ, viewport เต็ม)
+- [x]  **ดีไซน์ภาพ**:
+  - ควบคุมนำทางกึ่งโปร่งใสที่ด้านล่างกลาง
+  - ปุ่มวงกลม prev/next พร้อม hover effects
+  - สถานะปิดการใช้งานสำหรับขอบเขตสไลด์แรก/สุด��้าย
+  - Backdrop blur เพื่อการอ่านที่ดีขึ้น
+
+#### 5. ฟังก์ชันรีเซ็ตแอปพลิเคชัน
+- [x]  **ปุ่ม Reset** ต่อจาก Export Video
+  - รีเซ็ตแอปกลับสู่สถานะเริ่มต้น
+  - ล้างเนื้อหา markdown และสไลด์ทั้งหมด
+  - รีเซ็ตการตั้งค่ากลับเป็นค่าเริ่มต้น
+  - ยืนยันก่อนดำเนินการ (confirmation dialog)
+  - หยุดการเล่นหรือนำเสนออัตโนมัติ
+  - รีเซ็ตเทมเพลตเป็น 'modern'
+  - เคลียร์ไทม์ไลน์และ asset checklist
+
+#### 6. PowerPoint สำหรับโปรแกรมเมอร์ - Code Editor Themes
+- [x]  **Theme ใหม่สไตล์ Code Editor** ใน templates.js:
+  - **Monokai**: Theme คลาสสิก ใช้สี warm tones (magenta, green, cyan)
+  - **Solarized Dark**: Precision colors designed for readability
+  - **SynthWave '84**: Retro futuristic 80s aesthetic (hot pink, mint, yellow)
+  - **Dracula**: Dark theme สำหรับคนเขียนโค้ดตอนกลางคืน
+  - รองรับ syntax highlighting พร้อม theme-specific colors
+- [x]  **Enhanced Content Styles** ใน style.css:
+  - `.content-h1`: Gradient text with glow effect
+  - `.content-h2`: Border-left accent with text shadow
+  - `.content-blockquote`: Styled quote marks with inset shadow
+  - `.content-code-block`: Top gradient border with hover animation
+  - Syntax highlighting colors: keyword, string, number, comment, function, variable
+- [x]  **Advanced Transitions** ใน slide-renderer.js:
+  - **Glitch**: Digital glitch effect พร้อม random offsets และ hue rotation
+  - **Matrix**: Digital rain effect simulation
+  - **Cube**: 3D cube rotation transition
+  - **Pixelate**: Blur-based pixelation effect
+- [x]  **CSS Animations**:
+  - `@keyframes matrixScroll`: Scrolling matrix effect
+  - `@keyframes glitchSkew`: Skew animation for glitch
+  - `@keyframes pixelateIn`: Blur in animation
+  - `@keyframes codeHighlight`: Code block hover glow
+  - `@keyframes textGlow`: Heading pulsing glow effect
+
+#### 7. การแสดงภาพไทม์ไลน์ปรับปรุง
+- [x]  **ตัวบ่งชี้การแบ่งหน้า**: แสดง badges "[1/2]", "[2/2]" สำหรับสไลด์หลายหน้า
+- [x]  **แสดงจำนวนบรรทัด**: "8 lines", "5 lines" เพื่อแสดงความหนาแน่นเนื้อหา
+- [x]  **ตัวบ่งชี้ต่อเนื่อง**: "↪ continued" สำหรับเนื้อหาที่แบ่ง
+- [x]  **แสดงระยะเวลา**: เวลาที่แม่นยำต่อสไลด์พร้อมระยะเวลารวม
+
+#### 8. ระบบวัดผลและขอบปลอดภัยของ Smart Layout
+- [x] เพิ่ม heuristic `SMART_SAFE_ZONE` และ helper padding เพื่อให้ measurement stage กับเวทีจริงใช้อินเสตต์เดียวกัน
+- [x] ซิงก์ฟอนต์ คลาส screen-type และโครงสร้างซีนของ measurement stage ให้ตรงกับเวทีจริงทุกโหมดหน้าจอ
+- [x] ใช้ผลการวัดซ้ำในการสเกลคอนเทนต์หลังเรนเดอร์ พร้อมเผยค่า `data-safe-*` สำหรับการตรวจสอบ
+- [x] กรอง heading จากสไลด์ถัดไปเมื่อดึงคอนเทนต์มาพรีวิว และพึ่งพาหัวข้อที่ผู้ใช้เขียนแทน “Slide N” แบบสร้างเอง
+
+#### 9. ระบบตั้งค่าการนำเสนอ (`src/renderer/js/presentation-config.js`)
+- [x] ปรับแนวคิดเทมเพลตเดิมให้เป็นชุด preset แบบยืดหยุ่น (ฟอนต์ ขนาด clamp สี พื้นหลัง แอนิเมชัน)
+- [x] มี API จัดการคอนฟิก (`getCurrentConfig`, `setConfig`, `updateConfigPart`, `loadPreset`, `resetConfig`) ให้ควบคุมได้ละเอียด
+- [x] รวม preset หลัก (Default, Professional, Minimal, Creative) พร้อมตัวเลือกฟอนต์/พื้นหลัง/ทรานซิชันที่คัดสรรไว้
+- [x] ใช้งานค่า config กับ CSS custom properties โดยอัตโนมัติ โดยไม่พึ่งไลบรารีภายนอก
+- [x] รองรับการส่งออก/นำเข้า JSON เพื่อแชร์โปรไฟล์การนำเสนอระหว่างเด็ค Markdown
+
+### ไฟล์ตัวอย่างที่สร้าง
+- [x]  `workspace/complete-syntax-demo.md` - 25 สไลด์แสดงรูปแบบ Markdown syntax ทั้งหมด
+- [x]  `workspace/pagination-demo.md` - 20+ สไลด์แสดงการแบ่งหน้าอัตโนมัติพร้อมความยาวเนื้อหาหลากหลาย
+
+## อัปเดตล่าสุด (ตุลาคม 2025)
+
+### 10. ระบบแยกโหมดการทำงานอย่างเด็ดขาด (Mode Isolation System)
+**ปัญหาที่พบ**: UI elements จากโหมดต่างๆ ทำงานทับซ้อนกัน ทำให้เกิดความขัดแย้งและข้อผิดพลาดการแสดงผล
+
+**การแก้ไข** - สร้างระบบควบคุมโหมดแบบ exclusive mode switching:
+
+#### Mode Manager (`src/renderer/js/mode-manager.js`)
+- [x] **Singleton Pattern**: สร้าง `ModeManager` class เพียง instance เดียวสำหรับทั้งแอป
+- [x] **3 โหมดแยกกันอย่างเด็ดขาด**:
+  - **Intro Mode**: หน้าเริ่มต้น ไม่มีระบบใดทำงาน (static display only)
+  - **Presentation Mode**: โหมดนำเสนอ เปิดเฉพาะ keyboard navigation + Smart Layout
+  - **Editor Mode**: โหมดแก้ไข เปิดเฉพาะ content editable + drag & drop + Safe Zone border
+
+#### ระบบควบคุมที่รัดกุม
+- [x] **System Flags Tracking**: ติดตาม active systems (smartLayout, dragDrop, contentEditable, safeZoneBorder, etc.)
+- [x] **UI Visibility Control**: 
+  - `hideAllModeUI()` - ซ่อน UI elements ทั้งหมด
+  - `showPresentationUI()` - แสดงเฉพาะ navigation controls, exit button, fullscreen button, edit button
+  - `showEditorUI()` - แสดงเฉพาะ save button, cancel button, exit button
+- [x] **Smart Layout Management**:
+  - Intro Mode: `detach()` observers อย่างเด็ดขาด
+  - Presentation Mode: `reattach()` observers สำหรับ auto-adjustment
+  - Editor Mode: `detach()` observers เพื่อป้องกันการปรับขนาดขณะแก้ไข
+- [x] **Mode Switching Flow**:
+  ```javascript
+  switchMode(newMode) {
+    1. shutdownMode(currentMode)  // ปิดโหมดเดิมทั้งหมด
+    2. currentMode = newMode       // เปลี่ยนโหมด
+    3. setDisplayMode(newMode)     // อัปเดต config
+    4. activateMode(newMode)       // เปิดโหมดใหม่เท่านั้น
+    5. dispatch 'modeChanged' event
+  }
+  ```
+
+#### การผสานรวมกับระบบเดิม
+- [x] **app.js Integration**:
+  - `init()`: เรียก `switchToIntroMode()` แทน `setDisplayMode('intro')`
+  - `startPresentationMode()`: เรียก `switchToPresentationMode()`
+  - `exitPresentationMode()`: เรียก `switchToIntroMode()`
+  - ลบการ manual show/hide UI elements ทั้งหมด (Mode Manager จัดการให้)
+  
+- [x] **slide-editor.js Integration**:
+  - `enterEditMode()`: เรียก `switchToEditorMode()`
+  - `exitEditMode()`: เรียก `switchToPresentationMode()`
+  - `enterDragMode()`: เรียก `switchToEditorMode()`
+  - `exitDragMode()`: เรียก `switchToPresentationMode()`
+  - ลบการ manual Smart Layout detach/reattach (Mode Manager จัดการให้)
+  - ลบการ manual Safe Zone show/hide (Mode Manager จัดการให้)
+
+#### การป้องกัน Smart Layout ทำงานในโหมดที่ไม่ควร
+- [x] **Guard in `ensureContentWithinBounds()`**:
+  ```javascript
+  function ensureContentWithinBounds() {
+    const modeManager = getModeManager();
+    if (modeManager && !modeManager.isSystemActive('smartLayout')) {
+      return; // ห้ามทำงานถ้า Smart Layout ปิดอยู่
+    }
+    // ... คำนวณและปรับขนาดต่อ
+  }
+  ```
+
+#### ผลลัพธ์
+- [x] **ไม่มีการทับซ้อนของ UI**: แต่ละโหมดแสดง UI elements ที่เกี่ยวข้องเท่านั้น
+- [x] **ไม่มี Smart Layout รบกวน**: ระบบปรับขนาดทำงานเฉพาะ Presentation Mode
+- [x] **Edit Mode ปลอดภัย**: แก้ไขได้โดยไม่มีระบบอื่นมาขัดขวาง
+- [x] **Single Source of Control**: `ModeManager` เป็นจุดเดียวที่ควบคุมโหมดทั้งหมด
+
+#### เอกสารและการบำรุงรักษา
+- [x] สร้างเอกสาร `docs/TH/MODE_ISOLATION_FIX.md` พร้อมรายละเอียดการแก้ไข
+- [x] คอมเมนต์ในโค้ดชี้แจงว่า "Mode Manager จัดการแล้ว ไม่ต้อง manual control"
+- [x] ลบโค้ดซ้ำซ้อนออกจาก app.js และ slide-editor.js
+
+### ระบบแยกโลจิกทั้ง 3 ส่วนอย่างเด็ดขาด
+**หลักการ**: แต่ละโหมดการแสดงผลมีโลจิกและระบบ Safe Zone แยกกันโดยสิ้นเชิง เพื่อป้องกันการแก้ไขส่วนหนึ่งทำให้ส่วนอื่นเสียหาย
+
+#### 1. ระบบ Intro Scene (จอพรีวิวขนาดเล็กพร้อม UI Sidebar)
+- [x] **วัตถุประสงค์**: แสดงตัวอย่างสไลด์ในพื้นที่เล็กของหน้า UI พร้อมแถบควบคุมด้านข้าง
+- [x] **คุณสมบัติ**:
+  - [x] ขนาดหน้าจอคงที่ (1280x720 fallback)
+  - [x] Safe Zone แบบ hard-coded เหมาะสำหรับพื้นที่แสดงผลเล็ก
+  - [x] ไม่ต้องคำนวณแบบ dynamic เพราะพื้นที่แน่นอน
+- [x] **ฟังก์ชันหลัก** (ทำเครื่องหมาย LOCKED - ห้ามแก้ไข):
+  - [x] `getStagePreviewData()` - ดึงข้อมูลตัวอย่างสไลด์
+  - [x] `renderStagePreview()` - เรนเดอร์พรีวิวลงใน DOM
+  - [x] `updateStagePreview()` - อัปเดตพรีวิวเมื่อสไลด์เปลี่ยน
+- [x] **สถานะ**: ทำงานสมบูรณ์แล้ว - ห้ามแก้ไขหรือเชื่อมโยงกับโหมดอื่น
+
+#### 2. ระบบ Presentation Mode - Small Screen (จอนำเสนอขนาดปกติ)
+- [x] **วัตถุประสงค์**: โหมดนำเสนอบนจอปกติ (ไม่ fullscreen) ขนาด 1920x1080 หรือเล็กกว่า
+- [x] **คุณสมบัติ**:
+  - [x] รองรับการนำทางด้วยปุ่มลูกศร (← →)
+  - [x] คำนวณ Safe Zone แบบ ratio-based สำหรับหน้าจอปกติ
+  - [x] ขอบปลอดภัย (Safe Zone) ประมาณ 8-9% ของความกว้าง/สูง
+- [x] **โซนสี**:
+  - [x] **Red Zone**: พื้นที่นอกขอบหน้าจอ - ห้ามวางเนื้อหา
+  - [x] **Green Zone**: พื้นที่ปลอดภัยภายในขอบ - วางเนื้อหาได้อย่างปลอดภัย
+- [x] **การคำนวณ**:
+  - [x] ไม่ใช้ hard-coded pixels
+  - [x] คำนวณจาก ratio ของขนาดหน้าจอจริง
+  - [x] สูตร: `safeInset = screenDimension × SAFE_ZONE_RATIO`
+
+#### 3. ระบบ Presentation Mode - Large Screen (จอนำเสนอขนาดใหญ่เต็มจอ)
+- [x] **วัตถุประสงค์**: โหมด fullscreen บนจอขนาดใหญ่ (2560x1440 ขึ้นไป) หรือโปรเจคเตอร์
+- [x] **คุณสมบัติ**:
+  - [x] เข้าสู่ fullscreen mode อัตโนมัติ
+  - [x] Smart Layout Engine วัดและจัดเนื้อหาให้เหมาะสมกับพื้นที่
+  - [x] Safe Zone กว้างขึ้นเพื่อรองรับการ overscan ของโปรเจคเตอร์
+- [x] **โซนสี** (เข้มงวดกว่าจอเล็ก):
+  - [x] **Red Zone**: พื้นที่อันตราย 10-15% จากขอบ - ห้ามวางเนื้อหาเด็ดขาด
+  - [x] **Yellow Zone**: พื้นที่เตือน 5-10% - วางได้แต่อาจถูกตัดบนโปรเจคเตอร์บางรุ่น
+  - [x] **Green Zone**: พื้นที่ปลอดภัย 80% กลางจอ - วางเนื้��หาได้อย่างสบายใจ
+- [x] **การคำนวณ**:
+  - [x] คำนวณแบบ dynamic จากขนาดหน้าจอจริง
+  - [x] ปรับ ratio ตามประเภทจอ (normal/large/ultra)
+  - [x] ตัวอย่างสูตร:
+    ```
+    baseRatio = 0.08 (8%)
+    maxRatio = 0.16 (16%)
+    actualInset = clamp(screenSize × baseRatio, MIN_PIXELS, screenSize × maxRatio)
+    ```
+
+### การป้องกันโค้ดจากการแก้ไข
+- [x] เพิ่มคอมเมนต์เตือนทุกฟังก์ชันที่เกี่ยวข้องกับ Intro Scene
+- [x] ใช้แท็ก `@LOCKED` และ `DO NOT MODIFY` ชัดเจน
+- [x] แยกคอมเมนต์ออกเป็นบล็อกใหญ่ด้วยเส้นขอบ (==== lines)
+- [x] ระบุเหตุผลและผลกระทบของการแก้ไขในคอมเมนต์
+- [x] ไม่ใช้อิโมจิในคอมเมนต์ (อาจทำให้เกิดปัญหา encoding)
+
+### Smart Layout และ Safe Zone System
+- [x] แยก Safe Zone constants สำหรับแต่ละโหมด
+- [x] Intro Scene ใช้ constants แบบ hard-coded
+- [x] Presentation Mode จะสร้างฟังก์ชันคำนวณแยกต่างหาก
+- [ ] สร้างฟังก์ชัน `computePresentationSafeZone()` สำหรับโหมดนำเสนอ
+- [ ] สร้างฟังก์ชัน `computeLargeScreenSafeZone()` สำหรับจอใหญ่
+- [ ] ทดสอบการคำนวณ Safe Zone บนจอหลายขนาด
+
+## งานที่ต้องทำต่อ
+
+### เครื่องมือจัดวางอัจฉริยะ (Smart Layout)
+- [ ] **ผสาน Auto-pagination เข้า Smart Layout**:
+  - [ ] ใช้ logic การคำนวณบรรทัดจาก `slide-paginator.js` ร่วมกับ `ensureContentWithinBounds()`
+  - [ ] ทำให้สไลด์แบ่งอัตโนมัติตอน render จริง ไม่ใช่แค่ตอน parse
+  - [ ] คำนวณพื้นที่ว่างภายใน Safe Zone ก่อนตัดสินใจแบ่งหน้า
+  - [ ] เพิ่มการตั้งค่า `maxLinesPerSlide` ใน presentation-config.js
+- [ ] สร้าง `layout-schema.js` เวอร์ชันใหม่ที่นิยามโครงสร้าง LayoutNode และการรวม metrics แบบชัดเจน
+- [ ] ผูก layout tree กับกระบวนการ `renderSlideToStage` ให้เรนเดอร์ DOM ตามบล็อกแทนการใช้ HTML ดิบ
+- [ ] ปรับ measurement stage ให้ใช้ข้อมูลจาก layout tree พร้อม refactor การคำนวณบรรทัด/คอลัมน์
+- [ ] เพิ่ม unit tests สำหรับ smart layout (measurement observers, smart-list balancing, layout tree diff)
+
+### ระบบประสานงานระหว่างโมดูล Markdown → Layout → Renderer
+- [ ] สร้างเอกสาร `layout-contract.md` ระบุ schema JSON กลางสำหรับ slide/section/block/inline พร้อม diagnostics
+- [ ] ปรับ `markdown-syntax.js` ให้ปล่อย API เดียว (detect + inline tokenize) และบันทึก metadata ที่ parser ต้องใช้
+- [ ] ปรับ `markdown-parser.js` ให้ใช้ metadata นั้น สร้าง content item ที่พร้อม map ไปยัง layout block (เช่น link, inline emphasis)
+- [ ] อัปเดต `layout-schema.js` ให้รองรับ block ชนิดใหม่ (heading, link, inline rich text) พร้อม metrics ที่ renderer ใช้งานได้ทันที
+- [ ] ปรับ `app.js` ให้ใช้ layout tree ทั้งหมดในการเรนเดอร์, ส่งผล measurement/diagnostics กลับเข้า tree, และเผยสถานะต่อ UI
+- [ ] เพิ่ม feedback loop (diagnostics channel) ระหว่าง measurement stage ↔ layout-schema ↔ markdown-parser เพื่อให้ heuristics เรียนรู้ได้
+
+### โมเดลไทม์ไลน์และข้อมูลเมทาดาทา
+- [ ] เพิ่ม schema ฟรอนต์แมตเตอร์และอินไลน์ directive สำหรับเวลา ทรานซิชัน คิวบรรยาย และแอสเซ็ต
+- [ ] สร้างโมเดลไทม์ไลน์กลาง (JSON) ใช้งานร่วมกันระหว่าง renderer และ pipeline เอ็กซ์พอร์ต
+- [ ] ตรวจสอบความถูกต้องของเมทาดาทาพร้อมผลักข้อความผิดพลาดเข้าสู่ diagnostics ของ UI
+
+### 9. ระบบตั้งค่าการนำเสนอ (เสร็จสมบูรณ์ ✅)
+- [x] **วัตถุประสงค์**: ระบบปรับแต่งรูปลักษณ์แบบ Word/Excel พร้อมการประสานงานแบบสองทาง (UI ↔ Config ↔ Frontmatter ↔ CSS)
+- [x] **สถาปัตยกรรม**: แทนที่ระบบเทมเพลตแบบตายตัวด้วย configuration engine แบบไดนามิก พร้อมระบบตัวแปร CSS
+
+#### การควบคุมการจัดพิมพ์และเลย์เอาต์
+1. **การตั้งค่าฟอนต์** (9 อินพุต)
+   - [x] ช่วงขนาดฟอนต์แบบ responsive: H1 min/base/max, H2 min/base/max, Text min/base/max
+   - [x] ระบบ CSS `clamp()` อัตโนมัติสำหรับการปรับขนาดฟอนต์ตามหน้าจอ
+   - [x] หน่วยที่รองรับ: px, rem, em
+
+2. **การตั้งค่า Line Height** (2 อินพุต)
+   - [x] ระยะบรรทัดของ heading (default: 1.2)
+   - [x] ระยะบรรทัดของ body text (default: 1.6)
+   - [x] หน่วยที่รองรับ: ไม่มีหน่วย, em
+
+3. **การตั้งค่าการจัดวรรคตอน** (8 อินพุต)
+   - [x] ระยะห่างหน้าหลังพารากราฟ (px)
+   - [x] ระยะห่างหน้าหลังหัวข้อ (px)
+   - [x] การเยื้องบรรทัดแรก (px)
+   - [x] การเยื้องรายการ/ซ้ำซ้อน (px)
+   - [x] การจัดข้อความ (left, center, right, justify)
+
+4. **การตั้งค่าสี** (2 อินพุต)
+   - [x] สีหลัก (Accent Color) พร้อม picker สี
+   - [x] สีพื้นหลัง gradient
+
+#### การตั้งค่า UI และเอฟเฟกต์ภาพ
+- [x] **Preview Overlay Opacity** - ความทึบของ overlay พรีวิว (0-100%)
+- [x] **Overlay Background Blur** - ความเบลอของพื้นหลังตอนหยุด (0-20px)
+- [x] **Navigation Border Width** - ความหนาเส้นขอบปุ่มนำทาง (0-5px)
+- [x] **Backdrop Gradient Spread** - การกระจายของ gradient พื้นหลัง (40-80%)
+- [x] **Backdrop Blur Intensity** - ความเข้มเบลอของพื้นหลัง (0-60px)
+
+#### การตั้งค่าความกว้างขอบและเส้นเน้น
+- [x] **Heading Accent Border** - เส้นเน้นใต้หัวข้อ (0-8px)
+- [x] **Blockquote Left Border** - เส้นซ้าย blockquote (0-8px)
+- [x] **Image Border** - กรอบรอบรูปภาพ (0-8px)
+- [x] **Link Underline** - เส้นใต้ลิงก์ (0-4px)
+- [x] **Table Border** - เส้นขอบตาราง (0-4px)
+- [x] **Horizontal Rule** - ความหนาเส้นแบ่ง (0-6px)
+
+#### Single Source of Truth
+- [x] **CONFIG_PRESETS** ใน `presentation-config.js`:
+  * ค่าเริ่มต้นครบถ้วน 30+ properties
+  * Preset 4 แบบ: Default, Professional, Minimal, Creative
+  * แชร์ผ่าน frontmatter ได้
+
+- [x] **ระบบตัวแปร CSS** (23+ ตัวแปร):
+  * `--preview-opacity`, `--overlay-background`, `--overlay-blur`
+  * `--nav-border-width`, `--nav-border-opacity`
+  * `--backdrop-gradient-color`, `--backdrop-gradient-spread`, `--backdrop-blur`
+  * `--heading-accent-border-width`, `--blockquote-border-width`, `--image-border-width`
+  * `--link-underline-width`, `--table-border-width`, `--hr-border-width`
+  * ตัวแปรฟอนต์และระยะห่างทั้งหมด
+
+#### การประสานงานแบบสองทาง
+1. **UI → Config** (`syncUIToConfig()`)
+   - [x] รับค่าจากอินพุตพร้อมแปลงหน่วย (px, %, ไม่มีหน่วย)
+   - [x] อัปเดต `currentConfig` ทันที
+   - [x] เรียก `applyConfigToDOM()` เพื่อแสดงผล
+
+2. **Config → CSS** (`applyConfigToDOM()`)
+   - [x] ตั้งค่าตัวแปร CSS 23+ ตัวบน `document.documentElement`
+   - [x] แปลงเป็นสตริง CSS พร้อมหน่วย
+   - [x] อัปเดตทันทีในหน้าพรีวิว
+
+3. **Config → Frontmatter** (`savePresentationSettings()`)
+   - [x] บันทึกทุก property ลง YAML namespace `presentation.styles.*`
+   - [x] ตัวอย่าง: `presentation.styles.previewOpacity: 85`
+
+4. **Frontmatter → Config** (`loadConfigFromFrontmatter()`)
+   - [x] โหลดจาก YAML เมื่อเปิด markdown
+   - [x] merge เข้า currentConfig
+   - [x] เรียก `loadConfigToUI()` เพื่ออัปเดต UI
+
+#### ประสบการณ์นักพัฒนา
+- [x] **ไม่มีค่าแบบตายตัว**: ทุกอย่างอยู่ใน CONFIG_PRESETS.default.config
+- [x] **ง่ายต่อการขยาย**: เพิ่ม property ที่เดียว → ใช้ได้ทุกที่
+- [x] **รักษาได้ง่าย**: แก้ค่าเริ่มต้นที่เดียว → ผลทั่วทั้งระบบ
+- [x] **ปลอดภัย**: ตรวจสอบค่าและหน่วยทุกจุด
+
+#### การใช้งาน
+```yaml
+---
+presentation:
+  preset: "professional"  # หรือ "minimal", "creative"
+  styles:
+    h1FontBase: "3.5rem"
+    accentColor: "#3b82f6"
+    previewOpacity: 85
+    overlayBlur: 12
+    headingBorderWidth: 4
+    # ... properties อื่นๆ
+---
+```
+
+#### รายการตรวจสอบความสมบูรณ์
+- [x] 30+ UI controls ในแท็บ Presentation Settings
+- [x] 4 presets ที่กำหนดไว้ล่วงหน้า
+- [x] 23+ CSS variables พร้อมค่า fallback
+- [x] ฟังก์ชันผูกแบบสองทาง (UI ↔ config)
+- [x] การบันทึก/โหลด frontmatter สำหรับทุก property
+- [x] ปุ่ม Reset ใช้ `resetConfig()` แบบกลาง
+- [x] คลาส CSS สำหรับ table, hr, timeline indicators
+- [x] แปลเป็นภาษาอังกฤษทั้งหมด (UI + presets + help text)
+- [x] ไม่มี syntax errors ในทุกไฟล์
+- [x] เอกสารครบถ้วนใน EN/TH MARKDOWN_VIDEO_PLAN.md
+
+### เฟส 2: ปรับปรุงเอ็กซ์พอร์ต (ความสำคัญถัดไป)
+- [x]  พรีวิวแบบเบราว์เซอร์ใช้โมเดลไทม์ไลน์ได้อย่างไร้ที่ติพร้อม markdown rendering เต็มรูปแบบ
+- [ ] **ปรับปรุงคุณภาพการเอ็กซ์พอร์ต WebM แบบ native**:
+  - [ ] ปรับปรุง MediaRecorder API ให้ควบคุมเวลาแบบ frame-perfect
+  - [ ] ตัวเลือกการตั้งค่าคุณภาพ/bitrate (เป้าหมาย: 1080p ที่ 5-10 Mbps)
+  - [ ] รายงานความคืบหน้าพร้อมอัปเดตต่อสไลด์และแสดงเปอร์เซ็นต์
+  - [ ] ฟังก์ชันยกเลิก/หยุดสำหรับการเรนเดอร์ยาว
+- [ ] บริหารวงจรเรนเดอร์ด้วยคิวงาน รายงานความคืบหน้า และการยกเลิก
+- [ ] Modal ความคืบหน้าการเอ็กซ์พอร์ตพร้อมแสดง thumbnail แบบเรียลไทม์
+
+### การปรับแต่งภาพและแอนิเมชัน
+- [ ] รองรับพื้นหลังแบบภาพ/วิดีโอต่อสไลด์พร้อมการครอปรักษาอัตราส่วน
+- [ ] นิยาม DSL สำหรับทรานซิชัน แอนิเมชัน และการจัดวางแบบคีย์เฟรม
+- [ ] **สร้างคอมโพเนนต์กำหนดเอง** (ไม่ใช้ไลบรารีภายนอก):
+  - [ ] ตัวเรนเดอร์กราฟโดยใช้ Canvas 2D API
+  - [ ] ตัวไฮไลต์ syntax โดยใช้ regex tokenization
+  - [ ] Component registry สำหรับการแมป markdown → ภาพที่ขยายได้
+
+### เสียงและการบรรยาย (อนาคต)
+- [ ] รองรับแทร็กบรรยายที่ซิงก์กับไทม์ไลน์จากไฟล์เสียง
+- [ ] **ผสมเสียงโดยใช้ Web Audio API แบบ native**:
+  - [ ] สร้างอัลกอริทึม ducking กำหนดเองสำหรับดนตรีพื้นหลัง
+  - [ ] ซิงโครไนซ์เสียงกับไทม์ไลน์วิดีโอ
+  - [ ] ไม่ใช้ไลบรารีประมวลผลเสียงภายนอก
+- [ ] ตรวจสอบคุณภาพซิงก์เสียง-ภาพผ่านเทสต์สถานการณ์ตัวอย่าง
+
+### เวิร์กโฟลว์เทมเพลตและการทำงานร่วมกัน
+- [ ] สร้างระบบเลือกเทมเพลต Markdown + CSS ผ่าน UI
+- [ ] จัดทำพื้นที่เก็บแอสเซ็ตร่วมพร้อมการอ้างอิงเวอร์ชัน
+- [ ] จัดทำมาตรฐานการตั้งชื่อไฟล์และโครงสร้างโฟลเดอร์สำหรับมีเดีย
+
+## แผนดำเนินงานแบบเฟส
+
+### เฟส 1 – แกนไทม์ไลน์ ([x] เสร็จสมบูรณ์)
+- [x] เขียน `app.js` ใหม่เพื่อแยก markdown และเติมข้อมูล timeline UI
+- [x] ขยาย `markdown-parser.js` พร้อม frontmatter และการคำนวณระยะเวลา
+- [x] ผูกการเลือกเทมเพลตแบบสองทาง (UI ↔ frontmatter)
+- [x] แสดงข้อผิดพลาดการตรวจสอบในแท็บ Markdown
+- [x] **โบนัส**: พจนานุกรม Markdown Syntax ครบถ้วนพร้อม 50+ รูปแบบ
+- [x] **โบนัส**: ระบบแบ่งหน้าอัตโนมัติพร้อมการคำนวณบรรทัดแบบ visual
+- [x] **โบนัส**: ควบคุมพรีวิวแบบโต้ตอบ (หยุด/เล่นต่อ, ปุ่มลัด)
+- [x] **โบนัส**: การแสดงภาพไทม์ไลน์ปรับปรุงพร้อมตัวบ่งชี้และจำนวนบรรทัด
+- [x] **โบนัส**: โหมดนำเสนอเต็มรูปแบบพร้อมระบบนำทางและ fullscreen
+- [x] **โบนัส**: เวิร์กโฟลว์รีเซ็ตและระบบ Safe Zone อัจฉริยะที่ปกป้องเนื้อหา
+- [x] **โบนัส**: ธีม Code Editor พร้อมทรานซิชัน/แอนิเมชันระดับสูง
+- [x] **โบนัส**: ระบบตั้งค่าการนำเสนอแบบไม่มีเทมเพลต พร้อม preset ที่แชร์ได้
+- [ ] เพิ่ม unit tests สำหรับการแยกส่วน การคำนวณเวลา และกรณีผิดพลาด (เลื่อนไปเฟส 2)
+
+### เฟส 2 – ปรับปรุงเอ็กซ์พอร์ตวิดีโอ (ความสำคัญถัดไป)
+- [ ] ปรับปรุงคุณภาพการเอ็กซ์พอร์ต WebM ด้วย MediaRecorder และเฟรมที่แม่นยำ (เป้าหมาย: 1080p @ 5-10 Mbps)
+- [x] ใช้งานการติดตามความคืบหน้าแบบ native พร้อมอัปเดตต่อสไลด์และแสดงเปอร์เซ็นต์
+- [x] เพิ่มตัวควบคุมความละเอียด/FPS/คุณภาพที่ซิงก์กับ frontmatter
+- [ ] รองรับการยกเลิกระหว่างเอ็กซ์พอร์ตพร้อมทำความสะอาดและลบไฟล์บางส่วน
+- [ ] Modal ความคืบหน้าการเอ็กซ์พอร์ตพร้อมแสดง thumbnail แบบสด
+- [ ] Unit tests สำหรับ markdown-syntax.js, slide-paginator.js, กลไกหยุด/เล่นต่อ
+- [ ] สร้าง integration tests สำหรับ markdown ตัวอย่าง → วิดีโอ
+
+#### แผน Native Encoder ของระบบปฏิบัติการ (ความปลอดภัยสูง ไม่ใช้ไลบรารีภายนอก)
+- [ ] ออกแบบ pipeline ดึงเฟรมกลาง (HTML → บัฟเฟอร์ RGBA/PNG) ที่ใช้ร่วมกับ encoder ทุกแพลตฟอร์ม
+- [ ] Windows: สร้าง bridge Media Foundation แบบ sandbox เพื่อเขียน MP4 (H.264/AAC) ภายใต้การค��บคุมของ security-core
+- [ ] macOS: พัฒนา exporter ผ่าน AVFoundation (AVAssetWriter) สำหรับ H.264/AAC พร้อมตรวจสอบเส้นทางไฟล์อย่างเข้มงวด
+- [ ] Linux: เชื่อมกับ GStreamer/VA-API ที่มีในระบบ (`appsrc → x264enc → mp4mux`) โดยรันภายใต้เงื่อนไขความปลอดภัยเดียวกัน
+- [ ] เพิ่มการสร้าง GIF โดยใช้ pipeline native เดียวกัน (MF Transform, AVFoundation ImageDestination หรือ GStreamer gifenc)
+- [ ] ใส่ฮุคความปลอดภัยเพิ่มเติม (allow-list เส้นทาง, rate limit, ตรวจสอบ checksum) ในทุกการเรียก encoder
+
+### เฟส 3 – ผสานเสียง (อนาคต)
+- [ ] แยกการอ้างอิงไฟล์บรรยายจากข้อมูลเมทาสไลด์
+- [ ] โหลดและตรวจสอบแอสเซ็ตเสียงผ่าน IPC ที่ปลอดภัย
+- [ ] ผสมบรรยาย + ดนตรีพื้นหลังโดยใช้ Web Audio API
+- [ ] ซิงโครไนซ์เสียงกับไทม์ไลน์วิดีโอในพรีวิวและเอ็กซ์พอร์ต
+- [ ] เพิ่มการแสดงผลคลื่นเสียงในแท็บ Timeline
+
+### เฟส 4 – ปรับปรุงภาพ (อนาคต)
+- [ ] สร้างตัวเรนเดอร์กราฟแบบกำหนดเอง (Canvas-based ไม่มี libraries)
+- [ ] ใช้งาน syntax highlighter โดยใช้ regex tokenization
+- [ ] รองรับภาพ/วิดีโอพื้นหลังเฉพาะสไลด์
+- [ ] สร้าง animation DSL แบบ declarative สำหรับทรานซิชันแบบ keyframe
+- [ ] เพิ่ม component registry สำหรับการแมป markdown → ภาพที่ขยายได้
+
+### เฟส 5 – ทำให้เสถียรและปรับแต่ง (อนาคต)
+- [ ] วิเคราะห์ประสิทธิภาพและเพิ่มประสิทธิภาพแคชแอสเซ็ต
+- [ ] ปรับปรุงข้อความผิดพลาดพร้อมคำแนะนำแก้ไขตามบริบท
+- [ ] ปรับปรุงเอกสารพร้อมวิดีโอสอน
+- [ ] ส่งมอบ markdown decks ตัวอย่างที่แสดงฟีเจอร์ทั้งหมด
+
+## ผลกระทบด้านสถาปัตยกรรม
+- **[x] ขยาย `src/shared/markdown-parser.js`**: ปล่อย timeline JSON พร้อมข้อมูลเมทาฉาก ระยะเวลา อ้างอิงแอสเซ็ต ข้อมูลการแบ่งหน้า
+- **[x] สร้างใหม่ `src/shared/markdown-syntax.js`**: ไลบรารีรูปแบบแบบพจนานุกรมพร้อม 50+ regex patterns สำหรับ CommonMark + GFM ทั้งหมด
+- **[x] สร้างใหม่ `src/shared/slide-paginator.js`**: การคำนวณบรรทัดแบบ visual และอัลกอริทึมแบ่งสไลด์อัจฉริยะ
+- [ ] **สร้างใหม่ `src/shared/timeline-engine.js`**: ประกอบโมเดลไทม์ไลน์ คำนวณ timecodes จัดการสถานะการเล่น (อนาคต)
+- **[x] อัปเดต `src/renderer/js/app.js`**: 
+  * ใช้ markdown ที่แยกแล้วสำหรับพรีวิวพร้อมหยุด/เล่นต่อ
+  * เติม timeline พร้อมการเรนเดอร์ syntax เต็มรูปแบบ
+  * เพิ่มอ้างอิง DOM 13 ตัวสำหรับการตั้งค่าสไตล์ใหม่
+  * `savePresentationSettings()` บันทึก 11 properties สไตล์ลง frontmatter
+  * `resetApplication()` ใช้ `resetConfig()` แบบรวมศูนย์
+  * `buildSlideItemHtml()` ใช้คลาส `.slide-table`, `.slide-hr`
+  * `updateTimelineUI()` ใช้คลาส `.timeline-page-indicator`
+- **[x] ปรับปรุง `src/renderer/js/video-renderer.js`**: การเรนเดอร์สไลด์บน Canvas พร้อมรองรับ markdown เต็มรูปแบบ (พร้อมเอ็กซ์พอร์ต รอปรับปรุงคุณภาพ)
+- **[x] ระบบแอสเซ็ตท��่ปลอดภัย**: โฟลเดอร์ `workspace/` มาตรฐานพร้อมไฟล์ตัวอย่างและ emoji-cleaner.js
+- **[x] โมดูลใหม่ `src/renderer/js/presentation-config.js`**: 
+  * เอนจินตั้งค่าการนำเสนอแทนเทมเพลตแบบตายตัว
+  * `CONFIG_PRESETS` พร้อม 30+ properties, 4 presets
+  * `applyConfigToDOM()` ตั้งค่าตัวแปร CSS 23+ ตัวบน document.documentElement
+  * `loadConfigToUI()` โหลดทุกการตั้งค่ารวม 11 styling controls
+  * `syncUIToConfig()` ซิงก์การเปลี่ยนแปลง UI พร้อมแปลงหน่วย (px, %, ไม่มีหน่วย)
+  * `setupUIStylesListeners()` จัดการ input events สำหรับ 11 styling inputs
+  * `loadConfigFromFrontmatter()` โหลดทุก styling properties จาก YAML
+  * `resetConfig()` รีเซ็ตเป็นค่าเริ่มต้นแบบรวมศูนย์
+- **[x] อัปเดต `src/renderer/css/style.css`**:
+  * แปลงค่าตายตัวทั้งหมดเป็นตัวแปร CSS
+  * ประกาศตัวแปร 23+ ตัวพร้อมค่า fallback
+  * `.pause-overlay` ใช้ `var(--overlay-background)`, `var(--overlay-blur)`
+  * `.nav-btn` ใช้ `var(--nav-border-width)`, rgba พร้อม `var(--nav-border-opacity)`
+  * `.gradient-backdrop` ใช้ `var(--backdrop-gradient-color)`, `var(--backdrop-gradient-spread)`, `var(--backdrop-blur)`
+  * ความกว้างเส้นขอบทั้งหมด: `var(--*-border-width)` พร้อม fallbacks
+  * คลาสใหม่: `.slide-table`, `.slide-hr`, `.timeline-page-indicator` พร้อมสไตล์ที่เป็นธีม
+- **[x] อัปเดต `src/renderer/index.html`**:
+  * 30+ controls ในแท็บ Presentation Settings
+  * แบ่งเป็น 3 sections: UI Effects (5 inputs), Border Widths (6 inputs), Typography/Layout
+  * แปลเป็นภาษาอังกฤษทั้งหมด (หัวข้อ, labels, help text)
+  * เพิ่มข้อความช่วยเหลือแบบอธิบายสำหรับแต่ละ section
+
+## เทคโนโลยีที่ใช้งานปัจจุบัน (อัปเดต)
+- **Electron 28.0.0**: เฟรมเวิร์กแอปพลิเคชันเดสก์ท็อป
+- **MediaRecorder API**: การเข้ารหัสวิดีโอ WebM แบบ native (codec VP8/VP9)
+- **ตัวเข้ารหัส native (แผน)**: Windows Media Foundation, macOS AVFoundation, Linux GStreamer/VA-API (ใช้คอมโพเนนต์จากระบบ ไม่มี dependency ภายนอก)
+- **Canvas 2D API**: เรนเดอร์สไลด์จาก HTML/CSS → Canvas พร้อมรองรับ markdown syntax เต็มรูปแบบ
+- **Tailwind CSS (local - 407KB)**: UI styling โหลดจาก `src/renderer/vendor/tailwind.js`
+- **Web Audio API** (อนาคต): การผสมและปรับเสียงแบบ native
+- **โมดูลกำหนดเอง**:
+  - **MarkdownParser** (`src/shared/markdown-parser.js`) - Parser พร้อม frontmatter, duration heuristics, ผสาน pagination
+  - **MarkdownSyntax** (`src/shared/markdown-syntax.js`) - พจนานุกรมรูปแบบพร้อม 50+ regex สำหรับ CommonMark + GFM
+  - **SlidePaginator** (`src/shared/slide-paginator.js`) - การคำนวณบรรทัดแบบ visual และการแบ่งอัจฉริยะ
+  - **VideoRenderer** (`src/renderer/js/video-renderer.js`) - การเรนเดอร์สไลด์บน Canvas
+  - **PresentationConfig** (`src/renderer/js/presentation-config.js`) - ระบบ preset การนำเสนอและการตั้งค่ารันไทม์แบบไม่มีเทมเพลต
+  - **SecurityCore** (`src/shared/security-core.js`) - ตรวจสอบ path และจำกัดอัตราสำหรับการดำเนินการไฟล์
+
+## กลยุทธ์คุณภาพ
+- [ ] Unit tests สำหรับ `markdown-syntax.js` (การตรวจจับรูปแบบ การแยกส่วนแบบ inline)
+- [ ] Unit tests สำหรับ `slide-paginator.js` (การคำนวณบรรทัด อัลกอริทึมการแบ่ง)
+- [ ] Unit tests สำหรับ `markdown-parser.js` (การแยกส่วน frontmatter คำนวณระยะเวลา ผสาน pagination)
+- [ ] Integration tests สำหรับ workflow markdown → ไทม์ไลน์ → วิดีโอ
+- [ ] Snapshot tests สำหรับโครงสร้าง HTML ที่เรนเดอร์
+- [ ] รายการตรวจสอบ QA แบบ manual สำหรับคุณภาพการเอ็กซ์พอร์ตในความละเอียด/FPS ต่างๆ
+- [ ] การตรวจสอบการจัดการข้อผิดพลาด (ไฟล์หายไป frontmatter ผิดพลาด ฯลฯ)
+- [ ] เทสต์กลไกหยุด/เล่นต่อ (promise resolution, ปุ่มลัด)
+
+## เอกสารและการนำไปใช้
+- [x] **จัดทำคู่มือสองภาษา**: สร้างเอกสารครบถ้วน 6 ไฟล์
+  - [x] `MARKDOWN_SYNTAX.md` (EN/TH) - คู่มือ syntax ครบถ้วนพร้อมตัวอย่าง
+  - [x] `AUTO_PAGINATION.md` (EN/TH) - คู่มือระบบแบ่งหน้าพร้อมอัลกอริทึม
+  - [x] `PREVIEW_CONTROLS.md` (EN/TH) - คู่มือการใช้งานควบคุมแบบโต้ตอบ
+- [x] **สร้างเด็คตัวอย่าง**: สร้างไฟล์ markdown ตัวอย่าง
+  - [x] `workspace/complete-syntax-demo.md` - 25 สไลด์แสดงรูปแบบ syntax ทั้งหมด
+  - [x] `workspace/pagination-demo.md` - 20+ สไลด์แสดงการแบ่งหน้าอัตโนมัติ
+- [ ] วางแผนทดสอบกับผู้ใช้จริงและรวบรวมฟีดแบ็กเพื่อปรับปรุงต่อเนื่อง
+- [ ] จัดทำวิดีโอสอนสำหรับขั้นตอนเอ็กซ์พอร์ตและแก้ไขปัญหา

docs/TH/SECURITY.md

@@ -0,0 +1,72 @@
+# นโยบายความปลอดภัย
+
+## เวอร์ชันที่รองรับ
+
+เราปล่อยแพตช์สำหรับช่องโหว่ด้านความปลอดภัย เวอร์ชันใดที่มีสิทธิ์ได้รับแพตช์ดังกล่าวขึ้นอยู่กับการจัดอันดับ CVSS v3.0:
+
+| เวอร์ชัน | รองรับ              |
+| -------- | ------------------- |
+| 1.0.x    | :white_check_mark:  |
+| < 1.0    | :x:                 |
+
+## การรายงานช่องโหว่
+
+**โปรดอย่ารายงานช่องโหว่ด้านความปลอดภัยผ่าน GitHub issues สาธารณะ**
+
+แทนที่จะเป็นเช่นนั้น โปรดรายงานผ่านอีเมลไปที่: **[INSERT SECURITY EMAIL]**
+
+คุณควรได้รับการตอบกลับภายใน 48 ชั่วโมง หากคุณไม่ได้รับการตอบกลับด้วยเหตุผลบางอย่าง โปรดติดตามผ่านอีเมลเพื่อให้แน่ใจว่าเราได้รับข้อความเดิมของคุณ
+
+โปรดรวมข้อมูลต่อไปนี้ (เท่าที่คุณสามารถให้ได้) เพื่อช่วยให้เราเข้าใจธรรมชาติและขอบเขตของปัญหาที่เป็นไปได้:
+
+* ประเภทของปัญหา (เช่น buffer overflow, SQL injection, cross-site scripting ฯลฯ)
+* เส้นทางเต็มของไฟล์ต้นฉบับที่เกี่ยวข้องกับการแสดงออกของปัญหา
+* ตำแหน่งของ source code ที่ได้รับผลกระทบ (tag/branch/commit หรือ URL โดยตรง)
+* การตั้งค่าพิเศษที่จำเป็นในการทำซ้ำปัญหา
+* คำแนะนำทีละขั้นตอนในการทำซ้ำปัญหา
+* Proof-of-concept หรือ exploit code (ถ้าเป็นไปได้)
+* ผลกระทบของปัญหา รวมถึงวิธีที่ผู้โจมตีอาจใช้ประโยชน์จากปัญหา
+
+ข้อมูลนี้จะช่วยให้เราจัดลำดับความสำคัญรายงานของคุณได้เร็วขึ้น
+
+## ภาษาที่ต้องการ
+
+เราต้องการให้การสื่อสารทั้งหมดเป็นภาษาอังกฤษหรือไทย
+
+## กระบวนการอัปเดตความปลอดภัย
+
+1. **ได้รับรายงาน** - เรารับทราบการรับภายใน 48 ชั่วโมง
+2. **การสอบสวน** - เราสอบสวนและตรวจสอบความถูกต้องของช่องโหว่
+3. **การพัฒนาการแก้ไข** - เราพัฒนาและทดสอบการแก้ไข
+4. **คำแนะนำด้านความปลอดภัย** - เราเผยแพร่คำแนะนำด้านความปลอดภัยถ้าจำเป็น
+5. **ปล่อย** - เราปล่อยเวอร์ชันที่แพตช์แล้ว
+6. **การเปิดเผย** - เราเปิดเผยช่องโหว่สาธารณะหลังจากปล่อยการแก้ไขแล้ว
+
+## ข้อพิจารณาด้านความปลอดภัยที่ทราบ
+
+### การเข้าถึงระบบไฟล์
+
+แอปพลิเคชันนี้ต้องการการเข้าถึงระบบไฟล์เพื่อ:
+- อ่านไฟล์ Markdown
+- เขียนไฟล์วิดีโอที่เอ็กซ์พอร์ต
+- เข้าถึงโฟลเดอร์ workspace
+
+**การบรรเทา:**
+- การดำเนินการไฟล์ทั้งหมดผ่าน `security-core.js` พร้อมการตรวจสอบ path
+- Rate limiting ป้องกันการใช้งานในทางที่ผิด
+- ต้องได้รับความยินยอมจากผู้ใช้สำหรับการดำเนินการไฟล์
+
+### ความปลอดภัย Electron
+
+เราปฏิบัติตามแนวทางปฏิบัติที่ดีที่สุดด้านความปลอดภัยของ Electron:
+- เปิดใช้งาน context isolation
+- ปิด Node integration ใน renderer
+- Preload scripts สำหรับการสื่อสาร IPC
+- บังคับใช้ Content Security Policy
+
+### Dependencies จากบุคคลที่สาม
+
+เราทำสม่ำเสมอ:
+- อัปเดต dependencies เป็นเวอร์ชันที่ปลอดภัยล่าสุด
+- รัน `npm audit` เพื่อตรวจสอบช่องโหว่
+- ตรวจสอบใบอนุญาตและคำแนะนำด้านความปลอดภัยของ dependency

npm-runner.bat

@@ -0,0 +1,239 @@
+@echo off
+chcp 65001 > nul
+color 0A
+title Chahua Video Builder - Task Runner
+
+echo.
+
+:MENU
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                           🎬 Chahua Video Builder Toolkit                      ║
+echo ║                                    Version 1.0.0                              ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo.
+echo   --- Common Tasks ---
+echo    [1] npm install       (ติดตั้ง Dependencies - Electron only)
+echo    [2] npm start         (เปิดแอพพลิเคชัน Video Builder)
+echo    [3] npm run dev       (เปิดแอพพลิเคชันพร้อม DevTools)
+echo.
+echo   --- Build & Package ---
+echo    [4] npm run build     (Build ทุกแพลตฟอร์ม)
+echo    [5] npm run build:win (Build สำหรับ Windows เท่านั้น)
+echo    [6] npm run build:mac (Build สำหรับ macOS เท่านั้น)
+echo    [7] npm run build:linux (Build สำหรับ Linux เท่านั้น)
+echo.
+echo   --- Utilities ---
+echo    [8] Open Workspace    (เปิดโฟลเดอร์ workspace/)
+echo    [9] Open VS Code      (เปิดโปรเจ็กต์ใน VS Code)
+echo.
+echo    [0] Exit              (ออกจากโปรแกรม)
+echo.
+echo ===================================================
+echo.
+
+:: รับ Input จากผู้ใช้
+set /p "CHOICE=เลือกหมายเลข (0-9) และกด Enter: "
+
+:: ตรวจสอบตัวเลือก
+if "%CHOICE%"=="1" goto INSTALL
+if "%CHOICE%"=="2" goto START
+if "%CHOICE%"=="3" goto DEV
+if "%CHOICE%"=="4" goto BUILD
+if "%CHOICE%"=="5" goto BUILD_WIN
+if "%CHOICE%"=="6" goto BUILD_MAC
+if "%CHOICE%"=="7" goto BUILD_LINUX
+if "%CHOICE%"=="8" goto OPEN_WORKSPACE
+if "%CHOICE%"=="9" goto OPEN_CODE
+if "%CHOICE%"=="0" goto EXIT
+
+:: ถ้าพิมพ์ผิด
+echo.
+echo ❌ ตัวเลือกไม่ถูกต้อง กรุณาลองใหม่อีกครั้ง
+echo.
+pause
+goto MENU
+
+
+:: =================================
+:: ##     Action Sections         ##
+:: =================================
+
+:INSTALL
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                           📦 Installing Dependencies                           ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Installing Electron and electron-builder (only dependencies)...
+echo.
+call npm install
+echo.
+if %ERRORLEVEL% EQU 0 (
+    echo ✅ Installation completed successfully!
+) else (
+    echo ❌ Installation failed! Error code: %ERRORLEVEL%
+)
+echo.
+pause
+goto MENU
+
+:START
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                        🚀 Starting Video Builder App                           ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Launching Chahua Video Builder...
+echo Press Ctrl+C to stop the application.
+echo.
+call npm start
+echo.
+echo.
+echo ✅ Application closed.
+pause
+goto MENU
+
+:DEV
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                    🔧 Starting Development Mode (with DevTools)                ║
+echo ╚════════════════════════════════════════════════════════════════════════════════���
+echo.
+echo Launching with Developer Tools enabled...
+echo Press Ctrl+C to stop the application.
+echo.
+call npm run dev
+echo.
+echo.
+echo ✅ Development session ended.
+pause
+goto MENU
+
+:BUILD
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                      🏗️  Building for All Platforms                            ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Building Windows (NSIS), macOS (DMG), and Linux (AppImage)...
+echo This may take several minutes...
+echo.
+call npm run build
+echo.
+if %ERRORLEVEL% EQU 0 (
+    echo ✅ Build completed successfully!
+    echo 📁 Output: dist/ folder
+) else (
+    echo ❌ Build failed! Error code: %ERRORLEVEL%
+)
+echo.
+pause
+goto MENU
+
+:BUILD_WIN
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                        🪟 Building for Windows Only                            ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Building Windows installer (NSIS)...
+echo Output format: .exe installer
+echo.
+call npm run build:win
+echo.
+if %ERRORLEVEL% EQU 0 (
+    echo ✅ Windows build completed successfully!
+    echo 📁 Output: dist/ folder
+    echo 📦 Installer ready for distribution
+) else (
+    echo ❌ Build failed! Error code: %ERRORLEVEL%
+)
+echo.
+pause
+goto MENU
+
+:BUILD_MAC
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                         🍎 Building for macOS Only                             ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Building macOS installer (DMG)...
+echo ⚠️  Note: macOS builds work best on macOS systems
+echo.
+call npm run build:mac
+echo.
+if %ERRORLEVEL% EQU 0 (
+    echo ✅ macOS build completed successfully!
+    echo 📁 Output: dist/ folder
+) else (
+    echo ❌ Build failed! Error code: %ERRORLEVEL%
+)
+echo.
+pause
+goto MENU
+
+:BUILD_LINUX
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                        🐧 Building for Linux Only                              ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Building Linux installer (AppImage)...
+echo.
+call npm run build:linux
+echo.
+if %ERRORLEVEL% EQU 0 (
+    echo ✅ Linux build completed successfully!
+    echo 📁 Output: dist/ folder
+) else (
+    echo ❌ Build failed! Error code: %ERRORLEVEL%
+)
+echo.
+pause
+goto MENU
+
+:OPEN_WORKSPACE
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                          📂 Opening Workspace Folder                           ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Opening workspace/ folder for your code files...
+echo.
+if exist "workspace" (
+    explorer workspace
+    echo ✅ Workspace folder opened!
+) else (
+    echo ❌ Workspace folder not found!
+    echo Creating workspace folder...
+    mkdir workspace
+    echo ✅ Created workspace folder!
+    explorer workspace
+)
+echo.
+timeout /t 2 /nobreak > nul
+goto MENU
+
+:OPEN_CODE
+cls
+echo ╔════════════════════════════════════════════════════════════════════════════════╗
+echo ║                          💻 Opening in VS Code                                 ║
+echo ╚════════════════════════════════════════════════════════════════════════════════╝
+echo.
+echo Opening current project in Visual Studio Code...
+echo.
+code .
+if %ERRORLEVEL% EQU 0 (
+    echo ✅ VS Code opened successfully!
+) else (
+    echo ❌ Could not open VS Code. Is it installed?
+)
+echo.
+timeout /t 2 /nobreak > nul
+goto MENU
+
+:EXIT
+exit /b

package.json

@@ -0,0 +1,59 @@
+{
+  "name": "chahuadev-markdown-presenter",
+  "version": "2.0.0",
+  "description": "Transform Markdown into Professional Video Presentations - PowerPoint-style slides with animations and transitions. Truly offline-first, zero external dependencies.",
+  "main": "src/main/main.js",
+  "type": "module",
+  "scripts": {
+    "start": "electron .",
+    "dev": "electron . --enable-logging",
+    "build": "electron-builder",
+    "build:win": "electron-builder --win",
+    "build:mac": "electron-builder --mac",
+    "build:linux": "electron-builder --linux"
+  },
+  "keywords": [
+    "electron",
+    "markdown",
+    "presentation",
+    "chahuadev",
+    "markdown-to-video",
+    "slides",
+    "powerpoint",
+    "webm",
+    "gif",
+    "native",
+    "zero-dependencies"
+  ],
+  "author": "Chahua Development Co., Ltd.",
+  "license": "MIT",
+  "devDependencies": {
+    "electron": "^28.0.0",
+    "electron-builder": "^24.9.1"
+  },
+  "build": {
+    "appId": "com.chahuadev.markdownpresenter",
+    "productName": "Chahua Markdown Presenter",
+    "directories": {
+      "output": "dist"
+    },
+    "files": [
+      "**/*",
+      "!**/*.md",
+      "!dist",
+      "!node_modules"
+    ],
+    "win": {
+      "target": "nsis",
+      "icon": "icon.ico"
+    },
+    "mac": {
+      "target": "dmg",
+      "icon": "icon.icns"
+    },
+    "linux": {
+      "target": "AppImage",
+      "icon": "icon.png"
+    }
+  }
+}

src/main/main.js

@@ -0,0 +1,489 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Main Process
+// 100% Native Implementation - No External Dependencies
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { app, BrowserWindow, ipcMain, dialog } from 'electron';
+import path from 'node:path';
+import url from 'node:url';
+import fs from 'node:fs/promises';
+import { createReadStream, createWriteStream } from 'node:fs';
+import crypto from 'node:crypto';
+
+const appDir = path.dirname(url.fileURLToPath(import.meta.url));
+const rootDir = path.join(appDir, '..', '..');
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Security Manager Integration
+// ══════════════════════════════════════════════════════════════════════════════
+
+let SecurityManager;
+let securityInstance;
+
+async function initializeSecurity() {
+  try {
+    const securityModule = await import('../shared/security-core.js');
+    SecurityManager = securityModule.SecurityManager;
+    securityInstance = new SecurityManager({
+      EXTRA_ALLOWED_DIRS: [
+        app.getPath('documents'), 
+        app.getPath('downloads'),
+        path.join(rootDir, 'workspace'),
+        path.join(rootDir, 'examples')
+      ]
+    });
+    console.log('[Security] Security system initialized');
+    console.log('[Security] Whitelisted folders:', [
+      'Documents',
+      'Downloads', 
+      path.join(rootDir, 'workspace'),
+      path.join(rootDir, 'examples')
+    ]);
+  } catch (error) {
+    console.error('[Security] Failed to initialize security:', error);
+  }
+}
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Window Management
+// ══════════════════════════════════════════════════════════════════════════════
+
+const createWindow = async () => {
+  const win = new BrowserWindow({
+    width: 1600,
+    height: 1000,
+    minWidth: 1200,
+    minHeight: 700,
+    backgroundColor: '#020617',
+    autoHideMenuBar: true,
+    show: false,
+    webPreferences: {
+      preload: path.join(appDir, 'preload.cjs'),
+      contextIsolation: true,
+      nodeIntegration: false,
+      sandbox: false,
+      webSecurity: true
+    }
+  });
+
+  win.once('ready-to-show', () => {
+    win.show();
+  });
+
+  await win.loadFile(path.join(rootDir, 'src', 'renderer', 'index.html'));
+
+  // Dev tools in development mode
+  if (process.env.NODE_ENV === 'development') {
+    win.webContents.openDevTools();
+  }
+
+  return win;
+};
+
+// ══════════════════════════════════════════════════════════════════════════════
+// IPC Handlers - File Operations
+// ══════════════════════════════════════════════════════════════════════════════
+
+ipcMain.handle('file:selectFile', async () => {
+  try {
+    const result = await dialog.showOpenDialog({
+      title: 'Select Code File',
+      defaultPath: path.join(rootDir, 'workspace'),
+      properties: ['openFile'],
+      filters: [
+        { name: 'Code Files', extensions: ['js', 'ts', 'jsx', 'tsx', 'vue', 'svelte', 'py', 'java', 'cpp', 'c', 'cs', 'go', 'rs', 'rb', 'php'] },
+        { name: 'Web Files', extensions: ['html', 'css', 'scss', 'sass', 'less'] },
+        { name: 'Config Files', extensions: ['json', 'yml', 'yaml', 'toml', 'xml'] },
+        { name: 'All Files', extensions: ['*'] }
+      ]
+    });
+
+    if (result.canceled || result.filePaths.length === 0) {
+      return { success: false, canceled: true };
+    }
+
+    const filePath = result.filePaths[0];
+
+    // Security validation
+    if (securityInstance) {
+      const validation = await securityInstance.secureReadFile(filePath);
+      return {
+        success: true,
+        filePath: validation.filePath,
+        content: validation.content,
+        size: validation.size,
+        hash: validation.hash
+      };
+    } else {
+      // Fallback without security
+      const content = await fs.readFile(filePath, 'utf-8');
+      return {
+        success: true,
+        filePath,
+        content,
+        size: content.length
+      };
+    }
+  } catch (error) {
+    console.error('[File] Error selecting file:', error);
+    return {
+      success: false,
+      error: error.message
+    };
+  }
+});
+
+ipcMain.handle('file:readFile', async (event, filePath) => {
+  try {
+    if (securityInstance) {
+      const validation = await securityInstance.secureReadFile(filePath);
+      return {
+        success: true,
+        content: validation.content,
+        size: validation.size,
+        hash: validation.hash
+      };
+    } else {
+      const content = await fs.readFile(filePath, 'utf-8');
+      return {
+        success: true,
+        content,
+        size: content.length
+      };
+    }
+  } catch (error) {
+    console.error('[File] Error reading file:', error);
+    return {
+      success: false,
+      error: error.message
+    };
+  }
+});
+
+// ══════════════════════════════════════════════════════════════════════════════
+// IPC Handlers - Markdown Operations
+// ══════════════════════════════════════════════════════════════════════════════
+
+ipcMain.handle('markdown:openFile', async () => {
+  try {
+    const result = await dialog.showOpenDialog({
+      title: 'Open Markdown File',
+      defaultPath: path.join(rootDir, 'workspace'),
+      properties: ['openFile'],
+      filters: [
+        { name: 'Markdown Files', extensions: ['md', 'markdown'] },
+        { name: 'Text Files', extensions: ['txt'] },
+        { name: 'All Files', extensions: ['*'] }
+      ]
+    });
+
+    if (result.canceled || result.filePaths.length === 0) {
+      return { success: false, canceled: true };
+    }
+
+    const filePath = result.filePaths[0];
+
+    // Security validation
+    if (securityInstance) {
+      const validation = await securityInstance.secureReadFile(filePath);
+      return {
+        success: true,
+        filePath: validation.filePath,
+        content: validation.content,
+        size: validation.size,
+        hash: validation.hash
+      };
+    } else {
+      const content = await fs.readFile(filePath, 'utf-8');
+      return {
+        success: true,
+        filePath,
+        content,
+        size: content.length
+      };
+    }
+  } catch (error) {
+    console.error('[Markdown] Error opening file:', error);
+    return {
+      success: false,
+      error: error.message
+    };
+  }
+});
+
+ipcMain.handle('workspace:open', async () => {
+  try {
+    const workspacePath = path.join(rootDir, 'workspace');
+    
+    // Ensure workspace folder exists
+    try {
+      await fs.access(workspacePath);
+    } catch {
+      await fs.mkdir(workspacePath, { recursive: true });
+    }
+
+    // Open in system file explorer
+    const { shell } = await import('electron');
+    await shell.openPath(workspacePath);
+
+    return { success: true, path: workspacePath };
+  } catch (error) {
+    console.error('[Workspace] Error opening workspace:', error);
+    return {
+      success: false,
+      error: error.message
+    };
+  }
+});
+
+// ══════════════════════════════════════════════════════════════════════════════
+// IPC Handlers - Video Operations
+// ══════════════════════════════════════════════════════════════════════════════
+
+ipcMain.handle('video:saveVideo', async (event, { blob, format, filename }) => {
+  try {
+    const result = await dialog.showSaveDialog({
+      title: 'Save Video File',
+      defaultPath: path.join(rootDir, 'workspace', filename || `chahua-video-${Date.now()}.${format}`),
+      filters: [
+        { name: 'WebM Video', extensions: ['webm'] },
+        { name: 'All Files', extensions: ['*'] }
+      ]
+    });
+
+    if (result.canceled) {
+      return { success: false, canceled: true };
+    }
+
+    // Convert base64 to buffer
+    const buffer = Buffer.from(blob.split(',')[1], 'base64');
+    await fs.writeFile(result.filePath, buffer);
+
+    return {
+      success: true,
+      filePath: result.filePath,
+      size: buffer.length
+    };
+  } catch (error) {
+    console.error('[Video] Error saving video:', error);
+    return {
+      success: false,
+      error: error.message
+    };
+  }
+});
+
+ipcMain.handle('video:saveGIF', async (event, { frames, filename }) => {
+  try {
+    const result = await dialog.showSaveDialog({
+      title: 'Save GIF File',
+      defaultPath: path.join(rootDir, 'workspace', filename || `chahua-video-${Date.now()}.gif`),
+      filters: [
+        { name: 'GIF Files', extensions: ['gif'] },
+        { name: 'All Files', extensions: ['*'] }
+      ]
+    });
+
+    if (result.canceled) {
+      return { success: false, canceled: true };
+    }
+
+    // Simple GIF encoding (native implementation)
+    const gifBuffer = await encodeGIF(frames);
+    await fs.writeFile(result.filePath, gifBuffer);
+
+    return {
+      success: true,
+      filePath: result.filePath,
+      size: gifBuffer.length
+    };
+  } catch (error) {
+    console.error('[Video] Error saving GIF:', error);
+    return {
+      success: false,
+      error: error.message
+    };
+  }
+});
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Native GIF Encoder (Simple Implementation)
+// ══════════════════════════════════════════════════════════════════════════════
+
+async function encodeGIF(frames) {
+  // GIF Header
+  const header = Buffer.from('GIF89a', 'ascii');
+  
+  // Logical Screen Descriptor
+  const width = frames[0].width || 1920;
+  const height = frames[0].height || 1080;
+  const lsd = Buffer.alloc(7);
+  lsd.writeUInt16LE(width, 0);
+  lsd.writeUInt16LE(height, 2);
+  lsd[4] = 0xF7; // Global color table flag
+  lsd[5] = 0x00; // Background color
+  lsd[6] = 0x00; // Aspect ratio
+
+  // Simple color table (256 colors)
+  const colorTable = Buffer.alloc(768);
+  for (let i = 0; i < 256; i++) {
+    colorTable[i * 3] = i;
+    colorTable[i * 3 + 1] = i;
+    colorTable[i * 3 + 2] = i;
+  }
+
+  // Application Extension for looping
+  const appExt = Buffer.from([
+    0x21, 0xFF, 0x0B,
+    0x4E, 0x45, 0x54, 0x53, 0x43, 0x41, 0x50, 0x45,
+    0x32, 0x2E, 0x30,
+    0x03, 0x01, 0x00, 0x00, 0x00
+  ]);
+
+  const frameBuffers = [];
+  
+  for (const frame of frames) {
+    // Graphics Control Extension
+    const gce = Buffer.from([
+      0x21, 0xF9, 0x04,
+      0x04, // Disposal method
+      0x0A, 0x00, // Delay time (100ms)
+      0x00, // Transparent color
+      0x00
+    ]);
+
+    // Image Descriptor
+    const imgDesc = Buffer.alloc(10);
+    imgDesc[0] = 0x2C;
+    imgDesc.writeUInt16LE(0, 1); // Left
+    imgDesc.writeUInt16LE(0, 3); // Top
+    imgDesc.writeUInt16LE(width, 5); // Width
+    imgDesc.writeUInt16LE(height, 7); // Height
+    imgDesc[9] = 0x00;
+
+    // Image data (simplified - just use the frame data as-is)
+    const imageData = Buffer.from(frame.data || []);
+    
+    frameBuffers.push(Buffer.concat([gce, imgDesc, imageData]));
+  }
+
+  // Trailer
+  const trailer = Buffer.from([0x3B]);
+
+  return Buffer.concat([header, lsd, colorTable, appExt, ...frameBuffers, trailer]);
+}
+
+// ══════════════════════════════════════════════════════════════════════════════
+// IPC Handlers - Security Operations
+// ══════════════════════════════════════════════════════════════════════════════
+
+ipcMain.handle('security:getStats', async () => {
+  try {
+    if (securityInstance) {
+      return {
+        success: true,
+        stats: securityInstance.getSecurityStats()
+      };
+    }
+    return { success: false, error: 'Security not initialized' };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+});
+
+ipcMain.handle('security:exportLog', async () => {
+  try {
+    if (securityInstance) {
+      const log = securityInstance.exportSecurityLog();
+      
+      const result = await dialog.showSaveDialog({
+        title: 'Export Security Log',
+        defaultPath: path.join(rootDir, 'workspace', `security-log-${Date.now()}.json`),
+        filters: [
+          { name: 'JSON Files', extensions: ['json'] },
+          { name: 'All Files', extensions: ['*'] }
+        ]
+      });
+
+      if (result.canceled) {
+        return { success: false, canceled: true };
+      }
+
+      await fs.writeFile(result.filePath, JSON.stringify(log, null, 2));
+
+      return {
+        success: true,
+        filePath: result.filePath
+      };
+    }
+    return { success: false, error: 'Security not initialized' };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+});
+
+// ══════════════════════════════════════════════════════════════════════════════
+// IPC Handlers - System Operations
+// ══════════════════════════════════════════════════════════════════════════════
+
+ipcMain.handle('system:ping', () => {
+  return {
+    timestamp: Date.now(),
+    version: app.getVersion(),
+    platform: process.platform
+  };
+});
+
+ipcMain.handle('system:getInfo', () => {
+  return {
+    appVersion: app.getVersion(),
+    electronVersion: process.versions.electron,
+    nodeVersion: process.versions.node,
+    platform: process.platform,
+    arch: process.arch,
+    paths: {
+      documents: app.getPath('documents'),
+      downloads: app.getPath('downloads'),
+      workspace: path.join(rootDir, 'workspace'),
+      examples: path.join(rootDir, 'examples'),
+      root: rootDir
+    }
+  };
+});
+
+// ══════════════════════════════════════════════════════════════════════════════
+// App Initialization
+// ══════════════════════════════════════════════════════════════════════════════
+
+app.whenReady().then(async () => {
+  await initializeSecurity();
+  createWindow();
+
+  app.on('activate', () => {
+    if (BrowserWindow.getAllWindows().length === 0) {
+      createWindow();
+    }
+  });
+});
+
+app.on('window-all-closed', () => {
+  if (process.platform !== 'darwin') {
+    app.quit();
+  }
+});
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Error Handling
+// ══════════════════════════════════════════════════════════════════════════════
+
+process.on('uncaughtException', (error) => {
+  console.error('[Main] Uncaught Exception:', error);
+});
+
+process.on('unhandledRejection', (reason, promise) => {
+  console.error('[Main] Unhandled Rejection at:', promise, 'reason:', reason);
+});

src/main/preload.cjs

@@ -0,0 +1,73 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Preload Script
+// Secure Bridge between Main and Renderer Process
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+const { contextBridge, ipcRenderer } = require('electron');
+
+console.log('[Preload] Preload script loaded successfully');
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Exposed API to Renderer Process
+// ══════════════════════════════════════════════════════════════════════════════
+
+contextBridge.exposeInMainWorld('chahuaVideo', {
+  // ════════════════════════════════════════════════════════════════════════════
+  // File Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  selectFile: () => ipcRenderer.invoke('file:selectFile'),
+  
+  readFile: (filePath) => ipcRenderer.invoke('file:readFile', filePath),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Markdown Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  openMarkdownFile: () => ipcRenderer.invoke('markdown:openFile'),
+  
+  openWorkspaceFolder: () => ipcRenderer.invoke('workspace:open'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Video Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  saveVideo: (data) => ipcRenderer.invoke('video:saveVideo', data),
+  
+  saveGIF: (data) => ipcRenderer.invoke('video:saveGIF', data),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Security Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  getSecurityStats: () => ipcRenderer.invoke('security:getStats'),
+  
+  exportSecurityLog: () => ipcRenderer.invoke('security:exportLog'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // System Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  ping: () => ipcRenderer.invoke('system:ping'),
+  
+  getSystemInfo: () => ipcRenderer.invoke('system:getInfo'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Version Info
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  version: '1.0.0',
+  
+  platform: process.platform
+});
+
+console.log('[Preload] chahuaVideo API exposed to window object');
+console.log('[Preload] API includes:', [
+  'selectFile', 'readFile', 'openMarkdownFile', 'openWorkspaceFolder',
+  'saveVideo', 'saveGIF', 'getSecurityStats', 'exportSecurityLog',
+  'ping', 'getSystemInfo', 'version', 'platform'
+]);

src/main/preload.js

@@ -0,0 +1,61 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Preload Script
+// Secure Bridge between Main and Renderer Process
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { contextBridge, ipcRenderer } from 'electron';
+
+console.log('[Preload] Preload script loaded successfully');
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Exposed API to Renderer Process
+// ══════════════════════════════════════════════════════════════════════════════
+
+contextBridge.exposeInMainWorld('chahuaVideo', {
+  // ════════════════════════════════════════════════════════════════════════════
+  // File Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  selectFile: () => ipcRenderer.invoke('file:selectFile'),
+  
+  readFile: (filePath) => ipcRenderer.invoke('file:readFile', filePath),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Video Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  saveVideo: (data) => ipcRenderer.invoke('video:saveVideo', data),
+  
+  saveGIF: (data) => ipcRenderer.invoke('video:saveGIF', data),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Security Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  getSecurityStats: () => ipcRenderer.invoke('security:getStats'),
+  
+  exportSecurityLog: () => ipcRenderer.invoke('security:exportLog'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // System Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  ping: () => ipcRenderer.invoke('system:ping'),
+  
+  getSystemInfo: () => ipcRenderer.invoke('system:getInfo'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Version Info
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  version: '1.0.0',
+  
+  platform: process.platform
+});
+
+console.log('[Preload] chahuaVideo API exposed to window object');
+console.log('[Preload] Available methods:', Object.keys(window.chahuaVideo || {}));

src/main/preload.mjs

@@ -0,0 +1,61 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Preload Script (ES Module)
+// Secure Bridge between Main and Renderer Process
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { contextBridge, ipcRenderer } from 'electron';
+
+console.log('[Preload] Preload script loaded successfully');
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Exposed API to Renderer Process
+// ══════════════════════════════════════════════════════════════════════════════
+
+contextBridge.exposeInMainWorld('chahuaVideo', {
+  // ════════════════════════════════════════════════════════════════════════════
+  // File Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  selectFile: () => ipcRenderer.invoke('file:selectFile'),
+  
+  readFile: (filePath) => ipcRenderer.invoke('file:readFile', filePath),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Video Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  saveVideo: (data) => ipcRenderer.invoke('video:saveVideo', data),
+  
+  saveGIF: (data) => ipcRenderer.invoke('video:saveGIF', data),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Security Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  getSecurityStats: () => ipcRenderer.invoke('security:getStats'),
+  
+  exportSecurityLog: () => ipcRenderer.invoke('security:exportLog'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // System Operations
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  ping: () => ipcRenderer.invoke('system:ping'),
+  
+  getSystemInfo: () => ipcRenderer.invoke('system:getInfo'),
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Version Info
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  version: '1.0.0',
+  
+  platform: process.platform
+});
+
+console.log('[Preload] chahuaVideo API exposed to window object');
+console.log('[Preload] Available methods:', Object.keys(window.chahuaVideo || {}));

src/renderer/css/style.css

@@ -0,0 +1,2150 @@
+/* ══════════════════════════════════════════════════════════════════════════════
+   Chahua Video Builder - Main Stylesheet
+   Professional Edition - Clean and Modern Design
+   ══════════════════════════════════════════════════════════════════════════════
+   Company: Chahua Development Co., Ltd.
+   Version: 1.0.0
+   License: MIT
+   ══════════════════════════════════════════════════════════════════════════════ */
+
+/* ════════════════════════════════════════════════════════════════════════════
+   CSS Variables (Design Tokens)
+   ════════════════════════════════════════════════════════════════════════════ */
+
+:root {
+    /* Primary Colors - Dark Blue Theme */
+    --accent-color: #3b82f6;
+    --color-primary: #3b82f6;
+    --color-secondary: #06b6d4;
+    
+    /* Background Colors */
+    --color-background: #0a1628;
+    --color-surface: #132337;
+    --color-surface-hover: #1a2f47;
+    --color-border: #1e3a5f;
+    
+    /* Text Colors */
+    --color-text: #e2e8f0;
+    --color-text-secondary: #94a3b8;
+    --color-text-muted: #64748b;
+    
+    /* Accent Colors */
+    --color-cyan: #06b6d4;
+    --color-blue: #3b82f6;
+    --color-success: #10b981;
+    --color-warning: #f59e0b;
+    --color-error: #ef4444;
+    
+    /* Fonts */
+    --font-primary: 'Inter', sans-serif;
+    --font-code: 'Source Code Pro', monospace;
+    
+    /* Layout */
+    --border-radius: 0.75rem;
+    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
+    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
+    --content-spacing: 1.5rem;
+    
+    /* UI Elements (will be overridden by presentation-config.js) */
+    --preview-opacity: 0.68;
+    --overlay-background: rgba(10, 22, 40, 0.85);
+    --overlay-blur: 8px;
+    
+    /* Page Indicator (will be overridden by presentation-config.js) */
+    --page-indicator-top: 16px;
+    --page-indicator-right: 16px;
+    --page-indicator-font-size: 0.875rem;
+    --page-indicator-opacity: 0.7;
+    --page-indicator-padding-x: 12px;
+    --page-indicator-padding-y: 4px;
+    --page-indicator-bg-color: rgba(22, 78, 99, 0.5);
+    --page-indicator-text-color: #a5f3fc;
+    --nav-border-width: 2px;
+    --nav-border-opacity: 0.5;
+    
+    /* Borders & Accents */
+    --heading-accent-border-width: 4px;
+    --blockquote-border-width: 4px;
+    --image-border-width: 2px;
+    --link-underline-width: 2px;
+    --table-border-width: 1px;
+    --hr-border-width: 2px;
+    
+    /* Effects */
+    --backdrop-gradient-color: rgba(59, 130, 246, 0.15);
+    --backdrop-gradient-spread: 70%;
+    --backdrop-blur: 60px;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Base Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+}
+
+body {
+    font-family: var(--font-primary);
+    background-color: var(--color-background);
+    color: var(--color-text);
+    overflow-x: hidden;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Video Stage Components
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.stage-frame {
+    position: relative;
+    width: 100%;
+    padding-top: 56.25%; /* 16:9 aspect ratio */
+    border-radius: var(--border-radius);
+    overflow: hidden;
+    background: var(--color-surface);
+    border: 1px solid var(--color-border);
+    box-shadow: var(--shadow-lg);
+}
+
+#stage {
+    position: absolute;
+    inset: 0;
+    width: 100%;
+    height: 100%;
+    background-color: var(--color-surface);
+    overflow: hidden;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Smart Layout Enhancements
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.smart-layout-root .smart-list {
+    list-style: none;
+    padding: 0;
+    margin: 0 0 var(--content-spacing);
+    column-gap: 2.5rem;
+}
+
+.smart-layout-root .smart-list li {
+    margin-left: 2rem;
+    margin-bottom: 0.85rem;
+    line-height: var(--line-height-body, 1.45);
+}
+
+.smart-layout-root .smart-list.smart-balanced,
+.smart-layout-root .smart-list.smart-balanced-three {
+    column-fill: balance;
+}
+
+.smart-layout-root .smart-list.smart-balanced {
+    column-count: 2;
+}
+
+.smart-layout-root .smart-list.smart-balanced-three {
+    column-count: 3;
+}
+
+.smart-layout-root .smart-list.smart-balanced li,
+.smart-layout-root .smart-list.smart-balanced-three li {
+    break-inside: avoid;
+    margin-left: 1.25rem !important;
+}
+
+.smart-layout-root .smart-list.has-preview li[data-preview="true"] {
+    opacity: var(--preview-opacity);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Pause Overlay
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.pause-overlay {
+    position: absolute;
+    inset: 0;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    background-color: var(--overlay-background, rgba(10, 22, 40, 0.85));
+    backdrop-filter: blur(var(--overlay-blur, 8px));
+    z-index: 1000;
+    transition: opacity 0.3s ease;
+}
+
+.pause-overlay.hidden {
+    display: none;
+}
+
+.pause-indicator {
+    text-align: center;
+    animation: pulse-pause 2s ease-in-out infinite;
+}
+
+.pause-icon {
+    font-size: 6rem;
+    margin-bottom: 1rem;
+    filter: drop-shadow(0 4px 12px rgba(59, 130, 246, 0.5));
+}
+
+.pause-text {
+    font-size: 2rem;
+    font-weight: bold;
+    color: var(--color-primary);
+    text-transform: uppercase;
+    letter-spacing: 0.2em;
+    margin-bottom: 0.5rem;
+}
+
+.pause-hint {
+    font-size: 1rem;
+    color: var(--color-text-secondary);
+    opacity: 0.8;
+}
+
+@keyframes pulse-pause {
+    0%, 100% {
+        opacity: 1;
+        transform: scale(1);
+    }
+    50% {
+        opacity: 0.7;
+        transform: scale(1.05);
+    }
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Navigation Controls (Presentation Mode)
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.nav-controls {
+    position: absolute;
+    bottom: 2rem;
+    left: 50%;
+    transform: translateX(-50%);
+    display: flex;
+    align-items: center;
+    gap: 1rem;
+    z-index: 900;
+    transition: opacity 0.3s ease;
+}
+
+.nav-controls.hidden {
+    display: none;
+}
+
+.nav-btn {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 3rem;
+    height: 3rem;
+    background: var(--color-surface, rgba(19, 35, 55, 0.9));
+    border: var(--nav-border-width, 2px) solid rgba(59, 130, 246, var(--nav-border-opacity, 0.5));
+    border-radius: 50%;
+    color: var(--color-primary);
+    cursor: pointer;
+    transition: all 0.2s ease;
+    backdrop-filter: blur(10px);
+}
+
+.nav-btn:hover:not(:disabled) {
+    background: rgba(59, 130, 246, 0.2);
+    border-color: var(--color-primary);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
+}
+
+.nav-btn:disabled {
+    opacity: 0.3;
+    cursor: not-allowed;
+    border-color: rgba(100, 116, 139, 0.3);
+}
+
+.nav-arrow {
+    font-size: 1.5rem;
+    font-weight: bold;
+}
+
+.slide-counter {
+    padding: 0.5rem 1rem;
+    background: rgba(19, 35, 55, 0.9);
+    border: 2px solid rgba(59, 130, 246, 0.5);
+    border-radius: var(--border-radius);
+    color: var(--color-text);
+    font-size: 0.875rem;
+    font-weight: 600;
+    backdrop-filter: blur(10px);
+    min-width: 5rem;
+    text-align: center;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Fullscreen Button
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.fullscreen-btn {
+    position: absolute;
+    top: 1rem;
+    right: 1rem;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 2.5rem;
+    height: 2.5rem;
+    background: rgba(19, 35, 55, 0.9);
+    border: 2px solid rgba(59, 130, 246, 0.5);
+    border-radius: 0.5rem;
+    color: var(--color-primary);
+    cursor: pointer;
+    transition: all 0.2s ease;
+    backdrop-filter: blur(10px);
+    z-index: 900;
+}
+
+.fullscreen-btn:hover {
+    background: rgba(59, 130, 246, 0.2);
+    border-color: var(--color-primary);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
+}
+
+.fullscreen-btn.hidden {
+    display: none;
+}
+
+.fullscreen-icon {
+    font-size: 1.25rem;
+}
+
+/* Exit Presentation Mode Button */
+.exit-presentation-btn {
+    position: absolute;
+    top: 1rem;
+    right: 7.5rem;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 2.5rem;
+    height: 2.5rem;
+    background: rgba(239, 68, 68, 0.9);
+    border: 2px solid rgba(248, 113, 113, 0.5);
+    border-radius: 0.5rem;
+    color: white;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    backdrop-filter: blur(10px);
+    z-index: 900;
+}
+
+.exit-presentation-btn:hover {
+    background: rgba(239, 68, 68, 1);
+    border-color: rgba(248, 113, 113, 0.8);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.5);
+}
+
+.exit-presentation-btn.hidden {
+    display: none;
+}
+
+.exit-presentation-btn svg {
+    display: block;
+}
+
+/* Stop Preview Button */
+.stop-preview-btn,
+.stop-export-btn {
+    position: absolute;
+    top: 1rem;
+    right: 11rem;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 2.5rem;
+    height: 2.5rem;
+    background: rgba(251, 191, 36, 0.9);
+    border: 2px solid rgba(252, 211, 77, 0.5);
+    border-radius: 0.5rem;
+    color: #1e293b;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    backdrop-filter: blur(10px);
+    z-index: 900;
+}
+
+.stop-preview-btn:hover,
+.stop-export-btn:hover {
+    background: rgba(251, 191, 36, 1);
+    border-color: rgba(252, 211, 77, 0.8);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(251, 191, 36, 0.5);
+}
+
+.stop-preview-btn.hidden,
+.stop-export-btn.hidden {
+    display: none;
+}
+
+.stop-preview-btn svg,
+.stop-export-btn svg {
+    display: block;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Slide Edit Controls
+   ════════════════════════════════════════════════════════════════════════════ */
+
+/* Edit Slide Button (Pencil Icon) */
+.edit-slide-btn {
+    position: absolute;
+    top: 1rem;
+    right: 4.5rem;
+    z-index: 900;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 2.5rem;
+    height: 2.5rem;
+    background: rgba(59, 130, 246, 0.9);
+    backdrop-filter: blur(10px);
+    border: 2px solid rgba(96, 165, 250, 0.5);
+    border-radius: 0.5rem;
+    color: white;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.edit-slide-btn:hover {
+    background: rgba(59, 130, 246, 1);
+    border-color: rgba(96, 165, 250, 0.8);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.5);
+}
+
+.edit-slide-btn.active {
+    background: rgba(16, 185, 129, 0.9);
+    border-color: rgba(52, 211, 153, 0.5);
+}
+
+.edit-slide-btn.active:hover {
+    background: rgba(16, 185, 129, 1);
+    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.5);
+}
+
+.edit-slide-btn svg {
+    display: block;
+}
+
+/* Save Slide Button */
+.save-slide-btn {
+    position: absolute;
+    top: 1rem;
+    right: 8rem;
+    z-index: 900;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 2.5rem;
+    height: 2.5rem;
+    background: rgba(16, 185, 129, 0.9);
+    backdrop-filter: blur(10px);
+    border: 2px solid rgba(52, 211, 153, 0.5);
+    border-radius: 0.5rem;
+    color: white;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    animation: slideInRight 0.3s ease-out;
+}
+
+.save-slide-btn:hover {
+    background: rgba(16, 185, 129, 1);
+    border-color: rgba(52, 211, 153, 0.8);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.5);
+}
+
+.save-slide-btn svg {
+    display: block;
+}
+
+/* Cancel Edit Button */
+.cancel-edit-btn {
+    position: absolute;
+    top: 1rem;
+    right: 11.5rem;
+    z-index: 900;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 2.5rem;
+    height: 2.5rem;
+    background: rgba(239, 68, 68, 0.9);
+    backdrop-filter: blur(10px);
+    border: 2px solid rgba(248, 113, 113, 0.5);
+    border-radius: 0.5rem;
+    color: white;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    animation: slideInRight 0.3s ease-out;
+}
+
+.cancel-edit-btn:hover {
+    background: rgba(239, 68, 68, 1);
+    border-color: rgba(248, 113, 113, 0.8);
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.5);
+}
+
+.cancel-edit-btn svg {
+    display: block;
+}
+
+@keyframes slideInRight {
+    from {
+        opacity: 0;
+        transform: translateX(20px);
+    }
+    to {
+        opacity: 1;
+        transform: translateX(0);
+    }
+}
+
+/* Editable Slide Content */
+.slide-editable [contenteditable="true"] {
+    outline: 2px dashed rgba(59, 130, 246, 0.5);
+    outline-offset: 4px;
+    border-radius: 0.375rem;
+    padding: 0.5rem;
+    min-height: 2rem;
+    transition: all 0.2s ease;
+    cursor: text;
+}
+
+.slide-editable [contenteditable="true"]:hover {
+    outline-color: rgba(59, 130, 246, 0.8);
+    background: rgba(59, 130, 246, 0.05);
+}
+
+.slide-editable [contenteditable="true"]:focus {
+    outline: 2px solid rgba(59, 130, 246, 1);
+    outline-offset: 4px;
+    background: rgba(59, 130, 246, 0.1);
+}
+
+.slide-editable [contenteditable="true"]:empty:before {
+    content: attr(data-placeholder);
+    color: rgba(148, 163, 184, 0.5);
+    font-style: italic;
+}
+
+/* Edit Mode Indicator */
+.edit-mode-indicator {
+    position: absolute;
+    top: 1rem;
+    left: 1rem;
+    z-index: 900;
+    background: rgba(59, 130, 246, 0.95);
+    backdrop-filter: blur(10px);
+    border: 2px solid rgba(96, 165, 250, 0.5);
+    border-radius: 0.5rem;
+    padding: 0.5rem 1rem;
+    color: white;
+    font-size: 0.875rem;
+    font-weight: 600;
+    letter-spacing: 0.05em;
+    text-transform: uppercase;
+    animation: pulse 2s ease-in-out infinite;
+}
+
+@keyframes pulse {
+    0%, 100% {
+        opacity: 1;
+    }
+    50% {
+        opacity: 0.8;
+    }
+}
+
+/* ═══════════════════════════════════════════════════════════════════════════
+   DRAG & DROP SYSTEM STYLES
+   ═══════════════════════════════════════════════════════════════════════════ */
+
+/* Draggable content */
+.draggable-content {
+    cursor: move;
+    position: absolute !important;
+    user-select: none;
+    -webkit-user-select: none;
+    -moz-user-select: none;
+    -ms-user-select: none;
+    transition: box-shadow 0.2s ease, transform 0.1s ease;
+    pointer-events: auto;
+}
+
+.draggable-content:hover {
+    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.3);
+}
+
+.draggable-content.is-dragging {
+    cursor: grabbing !important;
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
+    transform: scale(1.02);
+    z-index: 9999 !important;
+    opacity: 0.9;
+    user-select: none !important;
+    -webkit-user-select: none !important;
+    pointer-events: none;
+}
+
+/* ป้องกันการ select ทั้ง stage ขณะลาก */
+.stage-dragging {
+    user-select: none !important;
+    -webkit-user-select: none !important;
+    cursor: grabbing !important;
+}
+
+.stage-dragging * {
+    pointer-events: none !important;
+}
+
+/* Drag handle */
+.drag-handle {
+    position: absolute;
+    left: -30px;
+    top: 50%;
+    transform: translateY(-50%);
+    width: 24px;
+    height: 24px;
+    background: rgba(59, 130, 246, 0.9);
+    border-radius: 6px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    cursor: grab;
+    opacity: 0;
+    transition: opacity 0.2s ease, background 0.2s ease;
+    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
+}
+
+.draggable-content:hover .drag-handle {
+    opacity: 1;
+}
+
+.drag-handle:hover {
+    background: rgba(59, 130, 246, 1);
+}
+
+.drag-handle:active {
+    cursor: grabbing;
+}
+
+.drag-handle svg {
+    color: white;
+    fill: currentColor;
+}
+
+/* Position locked */
+.position-locked {
+    cursor: not-allowed !important;
+}
+
+.position-locked .drag-handle {
+    background: rgba(156, 163, 175, 0.9);
+    cursor: not-allowed;
+}
+
+.position-locked:hover {
+    box-shadow: 0 0 0 2px rgba(156, 163, 175, 0.3);
+}
+
+/* Outside safe zone warning */
+.outside-safe-zone {
+    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.6) !important;
+    animation: shake 0.3s ease;
+}
+
+@keyframes shake {
+    0%, 100% { transform: translateX(0); }
+    25% { transform: translateX(-4px); }
+    75% { transform: translateX(4px); }
+}
+
+/* ═══════════════════════════════════════════════════════════════════════════
+   SAFE ZONE OVERLAY STYLES - กรอบสีแดงบังคับ
+   ═══════════════════════════════════════════════════════════════════════════ */
+
+.safe-zone-overlay {
+    position: fixed;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    pointer-events: none;
+    z-index: 8888;
+    opacity: 1;
+}
+
+.safe-zone-overlay.hidden {
+    opacity: 0;
+    pointer-events: none;
+}
+
+/* Safe zone borders - กรอบสีแดงบาง */
+.safe-zone-border {
+    position: fixed;
+    background: transparent;
+    pointer-events: none;
+}
+
+.safe-zone-top,
+.safe-zone-bottom {
+    height: 1px;
+    background: rgba(239, 68, 68, 0.8);
+    box-shadow: 0 0 4px rgba(239, 68, 68, 0.5);
+}
+
+.safe-zone-left,
+.safe-zone-right {
+    width: 1px;
+    background: rgba(239, 68, 68, 0.8);
+    box-shadow: 0 0 4px rgba(239, 68, 68, 0.5);
+}
+
+/* เอฟเฟกต์เมื่อลากใกล้ขอบ */
+.safe-zone-overlay.warning .safe-zone-border {
+    background: rgba(239, 68, 68, 1);
+    animation: pulse-red 0.5s ease infinite;
+}
+
+@keyframes pulse-red {
+    0%, 100% {
+        opacity: 1;
+        filter: brightness(1);
+    }
+    50% {
+        opacity: 0.7;
+        filter: brightness(1.5);
+    }
+}
+
+/* ═══════════════════════════════════════════════════════════════════════════
+   POSITION CONTROLS UI
+   ═══════════════════════════════════════════════════════════════════════════ */
+
+.position-controls {
+    position: fixed;
+    bottom: 2rem;
+    left: 2rem;
+    background: rgba(17, 24, 39, 0.95);
+    backdrop-filter: blur(10px);
+    border-radius: 12px;
+    padding: 1rem;
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    z-index: 9000;
+    display: flex;
+    gap: 0.5rem;
+    transition: all 0.3s ease;
+}
+
+.position-controls.hidden {
+    opacity: 0;
+    pointer-events: none;
+    transform: translateY(20px);
+}
+
+.position-control-btn {
+    width: 40px;
+    height: 40px;
+    background: rgba(59, 130, 246, 0.1);
+    border: 1px solid rgba(59, 130, 246, 0.3);
+    border-radius: 8px;
+    color: rgba(59, 130, 246, 1);
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: all 0.2s ease;
+    padding: 0;
+}
+
+.position-control-btn:hover {
+    background: rgba(59, 130, 246, 0.2);
+    border-color: rgba(59, 130, 246, 0.5);
+    transform: translateY(-2px);
+}
+
+.position-control-btn:active {
+    transform: translateY(0);
+}
+
+.position-control-btn.active {
+    background: rgba(59, 130, 246, 0.3);
+    border-color: rgba(59, 130, 246, 0.6);
+}
+
+.position-control-btn svg {
+    width: 20px;
+    height: 20px;
+}
+
+/* Position indicator */
+.position-indicator {
+    position: fixed;
+    top: 1rem;
+    left: 50%;
+    transform: translateX(-50%);
+    background: rgba(17, 24, 39, 0.95);
+    backdrop-filter: blur(10px);
+    border-radius: 8px;
+    padding: 0.5rem 1rem;
+    font-size: 0.875rem;
+    color: rgba(156, 163, 175, 1);
+    font-family: 'Courier New', monospace;
+    z-index: 9000;
+    pointer-events: none;
+    opacity: 0;
+    transition: opacity 0.2s ease;
+}
+
+.position-indicator.show {
+    opacity: 1;
+}
+
+.fullscreen-btn.hidden,
+.exit-presentation-btn.hidden,
+.stop-preview-btn.hidden,
+.stop-export-btn.hidden,
+.edit-slide-btn.hidden,
+.save-slide-btn.hidden,
+.cancel-edit-btn.hidden {
+    display: none;
+}
+
+/* Fullscreen mode adjustments */
+.stage-frame:fullscreen {
+    border-radius: 0;
+    padding-top: 0;
+}
+
+.stage-frame:fullscreen #stage {
+    width: 100vw;
+    height: 100vh;
+}
+
+.stage-frame:-webkit-full-screen {
+    border-radius: 0;
+    padding-top: 0;
+}
+
+.stage-frame:-webkit-full-screen #stage {
+    width: 100vw;
+    height: 100vh;
+}
+
+.stage-frame:-moz-full-screen {
+    border-radius: 0;
+    padding-top: 0;
+}
+
+.stage-frame:-moz-full-screen #stage {
+    width: 100vw;
+    height: 100vh;
+}
+
+.stage-frame:-ms-fullscreen {
+    border-radius: 0;
+    padding-top: 0;
+}
+
+.stage-frame:-ms-fullscreen #stage {
+    width: 100vw;
+    height: 100vh;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Scene Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.scene {
+    position: absolute;
+    inset: 0;
+    display: flex;
+    flex-direction: column;
+    justify-content: center;
+    align-items: center;
+    padding: 0;
+    opacity: 0;
+    transform: translateY(35px) scale(0.96);
+    transition: opacity 0.6s ease, transform 0.6s ease;
+    pointer-events: none;
+    overflow: hidden;
+    box-sizing: border-box;
+    word-break: break-word;
+    hyphens: auto;
+}
+
+.scene.active {
+    opacity: 1;
+    transform: translateY(0) scale(1);
+    pointer-events: auto;
+}
+
+.scene > * {
+    max-width: 100%;
+    word-wrap: break-word;
+    overflow-wrap: break-word;
+    word-break: break-word;
+}
+
+.scene .slide-content {
+    max-height: 100%;
+    max-width: 100%;
+    overflow: hidden;
+    display: flex;
+    flex-direction: column;
+    gap: 1.5rem;
+    text-align: var(--text-align, left);
+    line-height: var(--line-height-body, 1.7);
+}
+
+#stage.screen-large .scene,
+#stage.screen-ultra .scene {
+    justify-content: flex-start;
+    align-items: flex-start;
+    padding: 0;
+}
+
+#stage.screen-ultra .scene {
+    padding: 0;
+}
+
+#stage.screen-large [data-scene="body"] h1,
+#smartMeasurementStage.screen-large [data-scene="body"] h1,
+#stage.screen-ultra [data-scene="body"] h1,
+#smartMeasurementStage.screen-ultra [data-scene="body"] h1 {
+    font-size: var(--font-size-h1, clamp(2.5rem, 5vw, 4.5rem));
+    max-width: 100%;
+}
+
+#stage.screen-large [data-scene="body"] h2,
+#smartMeasurementStage.screen-large [data-scene="body"] h2,
+#stage.screen-ultra [data-scene="body"] h2,
+#smartMeasurementStage.screen-ultra [data-scene="body"] h2 {
+    font-size: var(--font-size-h2, clamp(2rem, 4vw, 3.5rem));
+    max-width: 100%;
+}
+
+#stage.screen-large [data-scene="body"] h3,
+#smartMeasurementStage.screen-large [data-scene="body"] h3,
+#stage.screen-ultra [data-scene="body"] h3,
+#smartMeasurementStage.screen-ultra [data-scene="body"] h3 {
+    font-size: var(--font-size-h3, clamp(1.75rem, 3vw, 2.75rem));
+    max-width: 100%;
+}
+
+#stage.screen-large [data-scene="body"] p,
+#smartMeasurementStage.screen-large [data-scene="body"] p,
+#stage.screen-large [data-scene="body"] li,
+#smartMeasurementStage.screen-large [data-scene="body"] li,
+#stage.screen-ultra [data-scene="body"] p,
+#smartMeasurementStage.screen-ultra [data-scene="body"] p,
+#stage.screen-ultra [data-scene="body"] li,
+#smartMeasurementStage.screen-ultra [data-scene="body"] li {
+    font-size: var(--font-size-text, clamp(1.25rem, 2vw, 2rem));
+    line-height: var(--line-height-body, 1.6);
+    max-width: 100%;
+}
+
+#stage.screen-ultra [data-scene="body"] p,
+#smartMeasurementStage.screen-ultra [data-scene="body"] p,
+#stage.screen-ultra [data-scene="body"] li,
+#smartMeasurementStage.screen-ultra [data-scene="body"] li {
+    font-size: var(--font-size-text, clamp(1.5rem, 2.2vw, 2.2rem));
+    max-width: 100%;
+}
+
+/* สำหรับหน้าจอใหญ่ ให้จัดเนื้อหาชิดซ้ายแทนกึ่งกลาง */
+#stage.screen-large .smart-layout-root,
+#stage.screen-ultra .smart-layout-root {
+    align-items: flex-start;
+}
+
+#stage.screen-large .slide-heading,
+#stage.screen-ultra .slide-heading {
+    text-align: left;
+    margin-left: 0;
+    margin-right: 0;
+    max-width: 95%;
+}
+
+#stage.screen-large .slide-text,
+#stage.screen-ultra .slide-text {
+    text-align: left;
+    margin-left: 0;
+    margin-right: 0;
+    max-width: 92%;
+}
+
+#stage.screen-large .smart-list,
+#stage.screen-ultra .smart-list {
+    margin-left: 0;
+    margin-right: 0;
+    max-width: 92%;
+}
+
+#stage.screen-large .slide-blockquote,
+#stage.screen-ultra .slide-blockquote {
+    margin-left: 0;
+    margin-right: 0;
+    max-width: 90%;
+}
+
+#stage.screen-large .slide-code,
+#stage.screen-ultra .slide-code {
+    margin-left: 0;
+    margin-right: 0;
+    max-width: 95%;
+}
+
+#stage.screen-large .slide-image,
+#stage.screen-ultra .slide-image {
+    margin-left: 0;
+    margin-right: auto;
+    max-width: 85%;
+}
+
+[data-preview="true"],
+.preview-block {
+    opacity: var(--preview-opacity);
+    border-top: 1px dashed rgba(96, 165, 250, 0.35);
+    padding-top: calc(var(--content-spacing) * 1.1);
+    margin-top: calc(var(--content-spacing) * 1.2);
+}
+
+.preview-block:first-child {
+    border-top: none;
+    padding-top: 0;
+    margin-top: 0;
+}
+
+.preview-block hr,
+hr.preview-block {
+    border-color: rgba(96, 165, 250, 0.35);
+}
+
+.gradient-backdrop {
+    position: absolute;
+    inset: -20%;
+    background: radial-gradient(
+        circle at center, 
+        var(--backdrop-gradient-color, rgba(59, 130, 246, 0.15)), 
+        transparent var(--backdrop-gradient-spread, 70%)
+    );
+    filter: blur(var(--backdrop-blur, 60px));
+    opacity: 0.6;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Typography - Paragraph & Text Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+p {
+    margin-top: var(--paragraph-spacing-before, 0.5rem);
+    margin-bottom: var(--paragraph-spacing-after, 1rem);
+    line-height: var(--line-height-body, 1.7);
+    text-align: var(--text-align, left);
+    text-indent: var(--indent-first-line, 0);
+}
+
+.content-text p {
+    color: var(--color-text);
+    font-size: var(--font-size-text, 1rem);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Code Block Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.code-block {
+    font-family: var(--font-code);
+    white-space: pre-wrap;
+    background: var(--color-surface);
+    border: 1px solid var(--color-border);
+    border-radius: var(--border-radius);
+    padding: 1.75rem;
+    color: var(--color-text);
+    box-shadow: var(--shadow);
+    max-width: 100%;
+    overflow-x: auto;
+    position: relative;
+    line-height: 1.6;
+}
+
+.code-block::before {
+    content: '';
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    height: 2px;
+    background: var(--gradient);
+}
+
+/* Syntax Highlighting with Theme Variables */
+.code-syntax .keyword,
+.code-block .keyword { 
+    color: var(--syntax-keyword, #f87171);
+    font-weight: 600;
+}
+
+.code-syntax .string,
+.code-block .string { 
+    color: var(--syntax-string, #34d399);
+}
+
+.code-syntax .comment,
+.code-block .comment { 
+    color: var(--syntax-comment, #6b7280); 
+    font-style: italic;
+    opacity: 0.8;
+}
+
+.code-syntax .function,
+.code-block .function { 
+    color: var(--syntax-function, #60a5fa);
+    font-weight: 500;
+}
+
+.code-syntax .number,
+.code-block .number { 
+    color: var(--syntax-number, #fbbf24); 
+}
+
+.code-syntax .variable,
+.code-block .variable {
+    color: var(--syntax-variable, #a78bfa);
+}
+
+/* Enhanced Content Styles with Typography Controls */
+.content-h1 h1,
+.content-h2 h2,
+.content-h3 h3,
+.content-h4 h4,
+.content-h5 h5,
+.content-h6 h6 {
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+    line-height: var(--line-height-heading, 1.3);
+    text-align: var(--text-align, left);
+}
+
+.content-h1 h1 {
+    color: var(--color-primary);
+    text-shadow: 0 0 20px var(--color-primary), 0 4px 12px rgba(0, 0, 0, 0.3);
+    font-size: var(--font-size-h1, clamp(2rem, 5vw, 3.5rem));
+    font-weight: 800;
+    letter-spacing: -0.02em;
+    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
+    -webkit-background-clip: text;
+    -webkit-text-fill-color: transparent;
+    background-clip: text;
+    max-width: 100%;
+    word-wrap: break-word;
+}
+
+.content-h2 h2 {
+    color: var(--color-secondary);
+    text-shadow: 0 0 15px var(--color-secondary);
+    font-size: var(--font-size-h2, clamp(1.75rem, 4vw, 2.75rem));
+    font-weight: 700;
+    border-left: var(--heading-accent-border-width, 4px) solid var(--color-primary);
+    padding-left: 1.5rem;
+    max-width: 100%;
+    word-wrap: break-word;
+}
+
+.content-h3 h3 {
+    color: var(--color-accent);
+    font-size: var(--font-size-h3, clamp(1.5rem, 3vw, 2rem));
+    font-weight: 600;
+    max-width: 100%;
+    word-wrap: break-word;
+}
+
+.content-blockquote blockquote {
+    border-left: var(--blockquote-border-width, 4px) solid var(--color-accent);
+    padding-left: var(--indent-blockquote, 1.5rem);
+    margin: 1.5rem 0;
+    font-style: italic;
+    color: var(--color-text-secondary);
+    background: rgba(var(--color-surface), 0.3);
+    padding: 1.5rem;
+    border-radius: var(--border-radius);
+    box-shadow: inset 0 0 20px rgba(0, 0, 0, 0.2);
+}
+
+.content-blockquote blockquote::before {
+    content: '"';
+    font-size: 4rem;
+    color: var(--color-accent);
+    opacity: 0.3;
+    position: absolute;
+    margin-left: -2rem;
+    margin-top: -1rem;
+}
+
+.content-list-item ul,
+.content-numbered-item ol {
+    margin-left: var(--list-indent, 2rem);
+    line-height: var(--line-height-body, 1.8);
+}
+
+.content-list-item li,
+.content-numbered-item li {
+    margin-bottom: 0.75rem;
+    color: var(--color-text);
+    text-align: var(--text-align, left);
+}
+
+.content-list-item li::marker {
+    color: var(--color-primary);
+    font-size: 1.2em;
+}
+
+/* Task List Styling */
+.content-task-list li {
+    list-style: none;
+    margin-left: -1.5rem;
+}
+
+.content-task-list li::before {
+    content: '☐';
+    color: var(--color-accent);
+    font-size: 1.5em;
+    margin-right: 0.75rem;
+}
+
+.content-task-list li.checked::before {
+    content: '☑';
+    color: var(--color-primary);
+}
+
+/* Image Styling */
+.content-image img {
+    border-radius: var(--border-radius);
+    box-shadow: var(--shadow);
+    max-width: 100%;
+    height: auto;
+    border: 2px solid var(--color-primary);
+}
+
+/* Link Styling */
+.content-link a {
+    color: var(--color-primary);
+    text-decoration: none;
+    border-bottom: 2px solid var(--color-primary);
+    padding-bottom: 2px;
+    transition: all 0.3s ease;
+}
+
+.content-link a:hover {
+    color: var(--color-secondary);
+    border-bottom-color: var(--color-secondary);
+    text-shadow: 0 0 10px var(--color-secondary);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Typography Components
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.badge {
+    letter-spacing: 0.35em;
+    font-size: 0.65rem;
+    text-transform: uppercase;
+    color: rgba(255, 255, 255, 0.6);
+    font-weight: 600;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Button Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.btn-primary {
+    background: var(--color-primary);
+    color: #fff;
+    padding: 0.75rem 1.5rem;
+    border-radius: var(--border-radius);
+    font-weight: 600;
+    border: none;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    box-shadow: 0 2px 4px rgba(59, 130, 246, 0.3);
+}
+
+.btn-primary:hover:not(:disabled) {
+    background: #2563eb;
+    box-shadow: 0 4px 8px rgba(59, 130, 246, 0.4);
+}
+
+.btn-primary:disabled {
+    opacity: 0.5;
+    cursor: not-allowed;
+}
+
+.btn-secondary {
+    background: var(--color-surface);
+    border: 1px solid var(--color-border);
+    color: var(--color-text);
+    padding: 0.75rem 1.5rem;
+    border-radius: var(--border-radius);
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.btn-secondary:hover:not(:disabled) {
+    border-color: var(--color-primary);
+    background: var(--color-surface-hover);
+}
+
+.btn-secondary:disabled {
+    opacity: 0.5;
+    cursor: not-allowed;
+}
+
+.btn-tertiary {
+    background: transparent;
+    border: 1px solid var(--color-border);
+    color: var(--color-text-secondary);
+    padding: 0.5rem 1rem;
+    border-radius: var(--border-radius);
+    font-weight: 500;
+    font-size: 0.875rem;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.btn-tertiary:hover:not(:disabled) {
+    border-color: var(--color-cyan);
+    color: var(--color-cyan);
+    background: rgba(6, 182, 212, 0.1);
+}
+
+/* Reset Button - Warning Style */
+#resetBtn {
+    border-color: rgba(239, 68, 68, 0.3);
+    color: #ef4444;
+}
+
+#resetBtn:hover:not(:disabled) {
+    border-color: var(--color-error);
+    background: rgba(239, 68, 68, 0.1);
+    color: #ef4444;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Configuration Panel Styles
+   ═════��══════════════════════════════════════════════════════════════════════ */
+
+.config-panel {
+    background: var(--color-surface);
+    backdrop-filter: blur(10px);
+    border: 1px solid var(--color-border);
+}
+
+.config-panel input,
+.config-panel textarea,
+.config-panel select {
+    background: var(--color-background);
+    border: 1px solid var(--color-border);
+    color: var(--color-text);
+    border-radius: var(--border-radius);
+    padding: 0.5rem 0.75rem;
+    width: 100%;
+    font-family: inherit;
+    transition: all 0.2s ease;
+}
+
+.config-panel textarea {
+    font-family: var(--font-code);
+    resize: vertical;
+}
+
+.config-panel input:focus,
+.config-panel textarea:focus,
+.config-panel select:focus {
+    outline: none;
+    border-color: var(--color-primary);
+    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Status & Progress Components
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.status-pill {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.5rem;
+    font-size: 0.75rem;
+    letter-spacing: 0.05em;
+    border-radius: 999px;
+    background: var(--color-surface);
+    border: 1px solid var(--color-border);
+    padding: 0.5rem 1rem;
+    font-weight: 600;
+    text-transform: uppercase;
+    color: var(--color-text-secondary);
+}
+
+.status-pill.online::before {
+    content: '';
+    display: block;
+    width: 0.5rem;
+    height: 0.5rem;
+    border-radius: 999px;
+    background: var(--color-success);
+    animation: pulse 2s ease-in-out infinite;
+}
+
+.status-pill.recording::before {
+    content: '';
+    display: block;
+    width: 0.5rem;
+    height: 0.5rem;
+    border-radius: 999px;
+    background: var(--color-error);
+    animation: pulse 1s ease-in-out infinite;
+}
+
+@keyframes pulse {
+    0%, 100% { 
+        opacity: 1; 
+    }
+    50% { 
+        opacity: 0.5; 
+    }
+}
+
+.pulse {
+    animation: pulse 2s ease-in-out infinite;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Advanced Transition Animations
+   ════════════════════════════════════════════════════════════════════════════ */
+
+@keyframes matrixScroll {
+    0% {
+        background-position: 0% 0%;
+    }
+    100% {
+        background-position: 0% 200%;
+    }
+}
+
+@keyframes glitchSkew {
+    0% {
+        transform: skew(0deg);
+    }
+    25% {
+        transform: skew(2deg);
+    }
+    50% {
+        transform: skew(-2deg);
+    }
+    75% {
+        transform: skew(1deg);
+    }
+    100% {
+        transform: skew(0deg);
+    }
+}
+
+@keyframes pixelateIn {
+    0% {
+        filter: blur(20px);
+        opacity: 0;
+    }
+    50% {
+        filter: blur(10px);
+    }
+    100% {
+        filter: blur(0px);
+        opacity: 1;
+    }
+}
+
+@keyframes scanline {
+    0% {
+        transform: translateY(-100%);
+    }
+    100% {
+        transform: translateY(100%);
+    }
+}
+
+/* Code Block Enhanced Animations */
+@keyframes codeHighlight {
+    0%, 100% {
+        box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
+    }
+    50% {
+        box-shadow: 0 8px 32px var(--color-primary), 0 0 40px rgba(var(--color-primary), 0.3);
+    }
+}
+
+.code-block:hover {
+    animation: codeHighlight 2s ease-in-out infinite;
+}
+
+/* Heading Glow Effects */
+@keyframes textGlow {
+    0%, 100% {
+        text-shadow: 0 0 10px var(--color-primary), 0 0 20px var(--color-primary);
+    }
+    50% {
+        text-shadow: 0 0 20px var(--color-primary), 0 0 40px var(--color-primary), 0 0 60px var(--color-secondary);
+    }
+}
+
+.content-h1 h1:hover,
+.content-h2 h2:hover {
+    animation: textGlow 1.5s ease-in-out infinite;
+}
+
+.progress-bar {
+    width: 100%;
+    height: 0.5rem;
+    background: var(--color-surface);
+    border: 1px solid var(--color-border);
+    border-radius: 999px;
+    overflow: hidden;
+}
+
+.progress-bar-fill {
+    height: 100%;
+    background: var(--color-primary);
+    border-radius: 999px;
+    transition: width 0.3s ease;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Template Card Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.template-card {
+    background: var(--color-surface);
+    border: 2px solid var(--color-border);
+    border-radius: var(--border-radius);
+    padding: 1rem;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.template-card:hover {
+    border-color: var(--color-cyan);
+    box-shadow: 0 0 0 1px var(--color-cyan);
+}
+
+.template-card.active {
+    border-color: var(--color-primary);
+    background: rgba(59, 130, 246, 0.1);
+    box-shadow: 0 0 0 1px var(--color-primary);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   File Upload Zone
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.file-upload-zone {
+    border: 2px dashed var(--color-border);
+    border-radius: var(--border-radius);
+    padding: 2rem;
+    text-align: center;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    background: var(--color-surface);
+}
+
+.file-upload-zone:hover {
+    border-color: var(--color-cyan);
+    background: rgba(6, 182, 212, 0.05);
+}
+
+.file-upload-zone.dragging {
+    border-color: var(--color-primary);
+    background: rgba(59, 130, 246, 0.1);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Security Badge
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.security-badge {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.5rem;
+    background: rgba(16, 185, 129, 0.1);
+    color: #10b981;
+    padding: 0.25rem 0.75rem;
+    border-radius: 0.5rem;
+    font-size: 0.75rem;
+    font-weight: 600;
+}
+
+.security-badge::before {
+    content: '';
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Tab System
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.tab-button {
+    padding: 0.75rem 1.5rem;
+    background: transparent;
+    border: none;
+    color: var(--color-text-secondary);
+    font-weight: 500;
+    cursor: pointer;
+    border-bottom: 2px solid transparent;
+    transition: all 0.3s ease;
+}
+
+.tab-button.active {
+    color: var(--color-primary);
+    border-bottom-color: var(--color-primary);
+}
+
+.tab-content {
+    display: none;
+}
+
+.tab-content.active {
+    display: block;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Slide Content Structured Styles - ใช้กับเนื้อหาจาก Markdown
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.smart-layout-root {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    width: 100%;
+    max-width: 100%;
+    gap: 1.5rem;
+    padding: 0;
+}
+
+.slide-heading {
+    text-align: center;
+    width: 100%;
+    max-width: 100%;
+    margin-left: auto;
+    margin-right: auto;
+    word-wrap: break-word;
+    overflow-wrap: break-word;
+    word-break: break-word;
+    line-height: var(--line-height-heading, 1.3);
+    hyphens: auto;
+}
+
+.slide-h1 {
+    font-size: var(--font-size-h1, clamp(1.75rem, 4.5vw, 3rem));
+    font-weight: 800;
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+    color: var(--color-primary);
+    text-shadow: 0 0 20px var(--color-primary);
+    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
+    -webkit-background-clip: text;
+    -webkit-text-fill-color: transparent;
+    background-clip: text;
+    max-width: 100%;
+}
+
+.slide-h2 {
+    font-size: var(--font-size-h2, clamp(1.5rem, 3.5vw, 2.5rem));
+    font-weight: 700;
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+    color: var(--color-secondary);
+    text-shadow: 0 0 15px var(--color-secondary);
+    max-width: 100%;
+}
+
+.slide-h3 {
+    font-size: var(--font-size-h3, clamp(1.25rem, 2.75vw, 1.9rem));
+    font-weight: 600;
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+    color: var(--color-cyan);
+    max-width: 100%;
+}
+
+.slide-h4 {
+    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
+    font-weight: 600;
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+}
+
+.slide-h5 {
+    font-size: clamp(1.1rem, 2vw, 1.5rem);
+    font-weight: 600;
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+}
+
+.slide-h6 {
+    font-size: clamp(1rem, 1.5vw, 1.25rem);
+    font-weight: 500;
+    margin-top: var(--heading-spacing-before, 1.5rem);
+    margin-bottom: var(--heading-spacing-after, 0.75rem);
+}
+
+.slide-text,
+.slide-text p {
+    font-size: var(--font-size-text, clamp(1.1rem, 1.8vw, 1.6rem));
+    line-height: var(--line-height-body, 1.7);
+    margin-top: var(--paragraph-spacing-before, 0.5rem);
+    margin-bottom: var(--paragraph-spacing-after, 1rem);
+    text-align: var(--text-align, center);
+    text-indent: var(--indent-first-line, 0);
+    max-width: 100%;
+    margin-left: auto;
+    margin-right: auto;
+    color: var(--color-text);
+    word-break: break-word;
+    overflow-wrap: break-word;
+}
+
+.slide-text-preview {
+    font-size: clamp(1rem, 1.6vw, 1.4rem);
+    color: var(--color-text-secondary);
+    font-style: italic;
+    opacity: 0.8;
+}
+
+.smart-list {
+    width: 100%;
+    max-width: 100%;
+    margin-left: auto;
+    margin-right: auto;
+    padding-left: var(--list-indent, 1.5rem);
+    list-style: none;
+}
+
+.slide-list-item {
+    font-size: var(--font-size-text, clamp(1.1rem, 1.8vw, 1.6rem));
+    line-height: var(--line-height-body, 1.7);
+    margin-bottom: 0.75rem;
+    padding-left: var(--list-indent, 1.5rem);
+    text-indent: calc(-1 * var(--list-indent, 1.5rem));
+    color: var(--color-text);
+    word-break: break-word;
+    overflow-wrap: break-word;
+}
+
+.slide-blockquote {
+    border-left: var(--blockquote-border-width, 4px) solid var(--color-cyan);
+    padding-left: var(--indent-blockquote, 1.5rem);
+    padding-top: 1rem;
+    padding-bottom: 1rem;
+    margin-left: var(--indent-blockquote, 1.5rem);
+    margin-top: var(--paragraph-spacing-before, 0.5rem);
+    margin-bottom: var(--paragraph-spacing-after, 1rem);
+    font-style: italic;
+    font-size: clamp(1.25rem, 2vw, 1.75rem);
+    line-height: var(--line-height-body, 1.7);
+    color: var(--color-text-secondary);
+    background: rgba(19, 35, 55, 0.3);
+    border-radius: 0.5rem;
+    max-width: 85%;
+}
+
+.slide-code {
+    max-width: 90%;
+    margin-left: auto;
+    margin-right: auto;
+    margin-top: var(--paragraph-spacing-before, 0.5rem);
+    margin-bottom: var(--paragraph-spacing-after, 1rem);
+}
+
+.slide-code .code-block {
+    font-family: var(--font-code, 'Source Code Pro', monospace);
+    font-size: var(--font-size-code, clamp(0.9rem, 1.5vw, 1.1rem));
+    line-height: 1.5;
+}
+
+.slide-image {
+    max-width: 80%;
+    height: auto;
+    border-radius: 0.75rem;
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
+    margin-left: auto;
+    margin-right: auto;
+    display: block;
+    margin-bottom: 1rem;
+    border: var(--image-border-width, 2px) solid var(--color-primary);
+}
+
+.slide-link {
+    color: var(--color-cyan);
+    text-decoration: underline;
+    text-decoration-thickness: var(--link-underline-width, 2px);
+    font-size: clamp(1.25rem, 2vw, 1.75rem);
+    transition: all 0.2s ease;
+}
+
+.slide-link:hover {
+    color: var(--color-secondary);
+    text-shadow: 0 0 10px var(--color-secondary);
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Table & HR Styles
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.slide-table {
+    width: 100%;
+    border-collapse: collapse;
+    margin-bottom: 1rem;
+    border: var(--table-border-width, 1px) solid var(--color-accent);
+}
+
+.slide-table th {
+    border: var(--table-border-width, 1px) solid var(--color-accent);
+    padding: 1rem;
+    background-color: var(--color-accent);
+    color: white;
+    font-weight: 600;
+    text-align: left;
+}
+
+.slide-table td {
+    border: var(--table-border-width, 1px) solid var(--color-accent);
+    padding: 0.75rem 1rem;
+    color: var(--color-text);
+}
+
+.slide-table tr:nth-child(even) {
+    background-color: rgba(var(--color-surface), 0.3);
+}
+
+.slide-hr {
+    border: 0;
+    border-top: var(--hr-border-width, 2px) solid var(--color-accent);
+    margin: 1.5rem 0;
+    opacity: 0.7;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Timeline Page Indicator
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.timeline-page-indicator {
+    font-size: 0.75rem;
+    padding: 0.125rem 0.5rem;
+    background-color: var(--color-accent);
+    color: var(--color-text);
+    border-radius: 0.25rem;
+    opacity: 0.8;
+}
+
+/* Slide Page Indicator (on stage) */
+.slide-page-indicator {
+    position: absolute;
+    top: var(--page-indicator-top, 16px);
+    right: var(--page-indicator-right, 16px);
+    font-size: var(--page-indicator-font-size, 0.875rem);
+    opacity: var(--page-indicator-opacity, 0.7);
+    z-index: 100;
+}
+
+.slide-page-indicator span {
+    display: inline-block;
+    padding: var(--page-indicator-padding-y, 4px) var(--page-indicator-padding-x, 12px);
+    background-color: var(--page-indicator-bg-color, rgba(22, 78, 99, 0.5));
+    color: var(--page-indicator-text-color, #a5f3fc);
+    border-radius: 0.375rem;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Collapsible Settings Sections
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.settings-section summary {
+    list-style: none;
+    transition: color 0.15s ease;
+    user-select: none;
+    cursor: pointer;
+}
+
+.settings-section summary::-webkit-details-marker {
+    display: none;
+}
+
+.settings-section summary > span:first-child {
+    display: inline-block;
+    transition: transform 0.15s ease;
+    font-size: 0.7em;
+}
+
+.settings-section[open] summary > span:first-child {
+    transform: rotate(90deg);
+}
+
+.settings-section summary:hover {
+    color: #e2e8f0;
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Responsive Design
+   ════════════════════════════════════════════════════════════════════════════ */
+
+@media (max-width: 768px) {
+    .stage-frame {
+        padding-top: 75%; /* Adjusted for mobile */
+    }
+    
+    .scene {
+        padding: 1.5rem;
+    }
+    
+    .code-block {
+        padding: 1rem;
+        font-size: 0.875rem;
+    }
+    
+    .smart-layout-root {
+        gap: 1rem;
+    }
+    
+    .slide-heading,
+    .slide-text,
+    .smart-list,
+    .slide-blockquote,
+    .slide-code {
+        max-width: 95%;
+    }
+}
+
+
+@media (max-width: 640px) {
+    .btn-primary,
+    .btn-secondary {
+        padding: 0.625rem 1.25rem;
+        font-size: 0.875rem;
+    }
+}
+
+/* ═══════════════════════════════════════════════════════════════════════════
+   EXIT CONFIRMATION DIALOG
+   ═══════════════════════════════════════════════════════════════════════════ */
+
+.exit-confirmation-dialog {
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    z-index: 10000;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.exit-confirmation-overlay {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background: rgba(0, 0, 0, 0.6);
+    backdrop-filter: blur(4px);
+    animation: fadeIn 0.15s ease;
+}
+
+.exit-confirmation-content {
+    position: relative;
+    background: #1e293b;
+    border-radius: 8px;
+    padding: 1.25rem;
+    max-width: 380px;
+    width: 90%;
+    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    animation: slideUp 0.2s ease;
+}
+
+.exit-confirmation-header {
+    margin-bottom: 1rem;
+}
+
+.exit-confirmation-header h3 {
+    margin: 0;
+    font-size: 1.125rem;
+    font-weight: 600;
+    color: #f1f5f9;
+}
+
+.exit-confirmation-body {
+    margin-bottom: 1.25rem;
+    color: #cbd5e1;
+    line-height: 1.5;
+    font-size: 0.875rem;
+}
+
+.exit-confirmation-body p {
+    margin: 0.5rem 0;
+}
+
+.exit-confirmation-body .warning-text {
+    color: #fbbf24;
+    font-weight: 500;
+}
+
+.exit-confirmation-footer {
+    display: flex;
+    gap: 0.5rem;
+}
+
+.exit-confirmation-footer button {
+    flex: 1;
+    padding: 0.5rem 0.75rem;
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    border-radius: 6px;
+    font-size: 0.8125rem;
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.15s ease;
+}
+
+.btn-exit-save {
+    background: rgba(59, 130, 246, 0.2);
+    color: #60a5fa;
+    border-color: rgba(59, 130, 246, 0.3);
+}
+
+.btn-exit-save:hover {
+    background: rgba(59, 130, 246, 0.3);
+    border-color: rgba(59, 130, 246, 0.5);
+}
+
+.btn-exit-discard {
+    background: rgba(239, 68, 68, 0.2);
+    color: #f87171;
+    border-color: rgba(239, 68, 68, 0.3);
+}
+
+.btn-exit-discard:hover {
+    background: rgba(239, 68, 68, 0.3);
+    border-color: rgba(239, 68, 68, 0.5);
+}
+
+.btn-exit-cancel {
+    background: rgba(71, 85, 105, 0.2);
+    color: #cbd5e1;
+    border-color: rgba(255, 255, 255, 0.1);
+}
+
+.btn-exit-cancel:hover {
+    background: rgba(71, 85, 105, 0.3);
+    border-color: rgba(255, 255, 255, 0.15);
+}
+
+@keyframes fadeIn {
+    from { opacity: 0; }
+    to { opacity: 1; }
+}
+
+@keyframes slideUp {
+    from {
+        opacity: 0;
+        transform: translateY(10px);
+    }
+    to {
+        opacity: 1;
+        transform: translateY(0);
+    }
+}
+
+/* ════════════════════════════════════════════════════════════════════════════
+   Markdown Drop Zone
+   ════════════════════════════════════════════════════════════════════════════ */
+
+.markdown-drop-zone {
+    position: relative;
+}
+
+.markdown-drop-zone textarea {
+    width: 100%;
+    transition: all 0.2s ease;
+}
+
+.markdown-drop-zone.drag-over textarea {
+    opacity: 0.3;
+    pointer-events: none;
+}
+
+.markdown-drop-zone .drop-overlay {
+    position: absolute;
+    inset: 0;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    background: rgba(10, 22, 40, 0.95);
+    border: 2px dashed var(--color-primary);
+    border-radius: var(--border-radius);
+    backdrop-filter: blur(8px);
+    z-index: 10;
+    pointer-events: none;
+}
+
+.markdown-drop-zone.drag-over .drop-overlay {
+    display: flex;
+}
+
+.drop-overlay.hidden {
+    display: none;
+}
+
+.drop-content {
+    text-align: center;
+    animation: slideUp 0.3s ease;
+}
+
+.drop-icon {
+    font-size: 4rem;
+    margin-bottom: 1rem;
+    animation: bounce 0.6s ease infinite;
+}
+
+.drop-text {
+    font-size: 1.25rem;
+    font-weight: 600;
+    color: var(--color-text);
+    margin-bottom: 0.5rem;
+}
+
+.drop-hint {
+    font-size: 0.875rem;
+    color: var(--color-text-secondary);
+}
+
+@keyframes bounce {
+    0%, 100% {
+        transform: translateY(0);
+    }
+    50% {
+        transform: translateY(-10px);
+    }
+}

src/renderer/index.html

@@ -0,0 +1,1002 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Chahua Markdown Video Studio</title>
+    
+    <!-- Local Stylesheets (Offline-first) -->
+    <script src="./vendor/tailwind.js"></script>
+    <link rel="stylesheet" href="../../assets/fonts/fonts.css">
+    <link rel="stylesheet" href="./css/style.css">
+</head>
+<body>
+    <main class="min-h-screen flex flex-col lg:flex-row gap-6 p-4 lg:p-8">
+        <!-- Left Panel - Video Stage -->
+        <section class="flex-1 flex flex-col gap-6">
+            <!-- Header -->
+            <header class="flex flex-col md:flex-row md:items-center md:justify-between gap-4">
+                <div>
+                    <h1 class="text-3xl font-bold bg-gradient-to-r from-blue-400 to-purple-500 bg-clip-text text-transparent">
+                        Markdown Video Studio
+                    </h1>
+                    <p class="text-slate-400 mt-1 flex items-center gap-2">
+                        Markdown-first authoring · Unified timeline engine
+                        <span class="security-badge">Enterprise Security</span>
+                    </p>
+                </div>
+                <div class="flex items-center gap-3">
+                    <span id="statusPill" class="status-pill online">Ready</span>
+                    <button id="securityBtn" class="btn-secondary px-3 py-2 text-sm" title="View Security Stats">
+                         Security
+                    </button>
+                </div>
+            </header>
+
+            <!-- Video Stage -->
+            <div class="stage-frame" id="stageFrame">
+                <div id="stage">
+                    <!-- Pause Overlay -->
+                    <div id="pauseOverlay" class="pause-overlay hidden">
+                        <div class="pause-indicator">
+                            <div class="pause-icon">⏸</div>
+                            <div class="pause-text">PAUSED</div>
+                            <div class="pause-hint">Click or press Space to resume</div>
+                            <div class="pause-hint" style="margin-top: 0.5rem; opacity: 0.6;">Press ESC to stop</div>
+                        </div>
+                    </div>
+
+                    <!-- Navigation Controls -->
+                    <div id="navControls" class="nav-controls hidden">
+                        <button id="prevSlideBtn" class="nav-btn nav-btn-prev" title="Previous Slide (←)">
+                            <span class="nav-arrow">←</span>
+                        </button>
+                        <button id="nextSlideBtn" class="nav-btn nav-btn-next" title="Next Slide (→)">
+                            <span class="nav-arrow">→</span>
+                        </button>
+                        <div id="slideCounter" class="slide-counter">1 / 1</div>
+                    </div>
+
+                    <!-- Exit Presentation Mode Button -->
+                    <button id="exitPresentationBtn" class="exit-presentation-btn hidden" title="Exit Presentation Mode (ESC)">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                            <line x1="18" y1="6" x2="6" y2="18"></line>
+                            <line x1="6" y1="6" x2="18" y2="18"></line>
+                        </svg>
+                    </button>
+
+                    <!-- Stop Preview Button -->
+                    <button id="stopPreviewBtn" class="stop-preview-btn hidden" title="Stop Preview">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                            <rect x="6" y="6" width="12" height="12"></rect>
+                        </svg>
+                    </button>
+
+                    <!-- Stop Export Button -->
+                    <button id="stopExportBtn" class="stop-export-btn hidden" title="Stop Export">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                            <rect x="6" y="6" width="12" height="12"></rect>
+                        </svg>
+                    </button>
+
+                    <!-- Fullscreen Button -->
+                    <button id="fullscreenBtn" class="fullscreen-btn hidden" title="Toggle Fullscreen (F)">
+                        <span class="fullscreen-icon">⛶</span>
+                    </button>
+
+                    <!-- Slide Edit Button (Presentation Mode) -->
+                    <button id="editSlideBtn" class="edit-slide-btn hidden" title="Edit Current Slide (E)">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                            <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"></path>
+                            <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"></path>
+                        </svg>
+                    </button>
+
+                    <!-- Save Slide Edit Button (shown after editing) -->
+                    <button id="saveSlideBtn" class="save-slide-btn hidden" title="Save Slide Changes (Ctrl+S)">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                            <path d="M19 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v11a2 2 0 0 1-2 2z"></path>
+                            <polyline points="17 21 17 13 7 13 7 21"></polyline>
+                            <polyline points="7 3 7 8 15 8"></polyline>
+                        </svg>
+                    </button>
+
+                    <!-- Cancel Edit Button -->
+                    <button id="cancelEditBtn" class="cancel-edit-btn hidden" title="Cancel Changes (ESC)">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                            <line x1="18" y1="6" x2="6" y2="18"></line>
+                            <line x1="6" y1="6" x2="18" y2="18"></line>
+                        </svg>
+                    </button>
+
+                    <!-- Position Controls -->
+                    <div id="positionControls" class="position-controls hidden">
+                        <button id="toggleSafeZoneBtn" class="position-control-btn" title="แสดง/ซ่อน Safe Zone">
+                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                <rect x="3" y="3" width="18" height="18" rx="2" ry="2"></rect>
+                                <path d="M3 9h18M9 21V9"></path>
+                            </svg>
+                        </button>
+                        <button id="toggleSnapGridBtn" class="position-control-btn" title="Snap to Grid">
+                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                <circle cx="12" cy="12" r="1"></circle>
+                                <circle cx="12" cy="6" r="1"></circle>
+                                <circle cx="12" cy="18" r="1"></circle>
+                                <circle cx="6" cy="12" r="1"></circle>
+                                <circle cx="18" cy="12" r="1"></circle>
+                                <circle cx="6" cy="6" r="1"></circle>
+                                <circle cx="6" cy="18" r="1"></circle>
+                                <circle cx="18" cy="6" r="1"></circle>
+                                <circle cx="18" cy="18" r="1"></circle>
+                            </svg>
+                        </button>
+                        <button id="resetPositionsBtn" class="position-control-btn" title="รีเซ็ตตำแหน่งทั้งหมด">
+                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                <polyline points="1 4 1 10 7 10"></polyline>
+                                <polyline points="23 20 23 14 17 14"></polyline>
+                                <path d="M20.49 9A9 9 0 0 0 5.64 5.64L1 10m22 4l-4.64 4.36A9 9 0 0 1 3.51 15"></path>
+                            </svg>
+                        </button>
+                        <button id="exportSettingsBtn" class="position-control-btn" title="ส่งออกการตั้งค่า">
+                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"></path>
+                                <polyline points="7 10 12 15 17 10"></polyline>
+                                <line x1="12" y1="15" x2="12" y2="3"></line>
+                            </svg>
+                        </button>
+                    </div>
+
+                    <!-- Position Indicator -->
+                    <div id="positionIndicator" class="position-indicator">
+                        X: <span id="posX">0</span> | Y: <span id="posY">0</span>
+                    </div>
+                    
+                    <div class="gradient-backdrop"></div>
+
+                    <div id="slideContainer" class="flex flex-col gap-12">
+                        <div class="scene active" data-scene="intro">
+                            <span class="badge">intro</span>
+                            <h2 data-bind="intro.title" class="text-4xl md:text-6xl font-bold mt-4 text-center max-w-3xl">
+                                Markdown Video Studio
+                            </h2>
+                            <p data-bind="intro.subtitle" class="text-lg md:text-2xl text-slate-300 mt-6 text-center max-w-2xl">
+                                Define every slide, timing, and asset straight from your markdown deck.
+                            </p>
+                            <div class="mt-10 flex flex-wrap items-center justify-center gap-3 text-xs uppercase tracking-wider text-slate-400">
+                                <span> Markdown-driven timeline</span>
+                                <span> Unified preview & export</span>
+                                <span> Extensible components</span>
+                            </div>
+                        </div>
+
+                        <div class="scene" data-scene="body">
+                            <span class="badge">timeline</span>
+                            <div class="w-full max-w-4xl mx-auto bg-slate-900/60 rounded-2xl border border-slate-800/70 p-6">
+                                <h3 class="text-2xl font-semibold text-slate-300 mb-4">Live Timeline</h3>
+                                <ul id="timelinePreview" class="space-y-3 text-slate-200 text-sm">
+                                    <li class="flex items-start justify-between gap-3">
+                                        <span class="font-semibold">Slide 1 · Intro</span>
+                                        <span class="opacity-70">00:00 → 00:05</span>
+                                    </li>
+                                    <li class="flex items-start justify-between gap-3">
+                                        <span class="font-semibold">Slide 2 · Agenda</span>
+                                        <span class="opacity-70">00:05 → 00:15</span>
+                                    </li>
+                                    <li class="flex items-start justify-between gap-3">
+                                        <span class="font-semibold">Slide 3 · Demo</span>
+                                        <span class="opacity-70">00:15 → 00:35</span>
+                                    </li>
+                                </ul>
+                                <p class="text-xs text-slate-500 mt-4">
+                                    Timeline updates whenever the markdown deck changes.
+                                </p>
+                            </div>
+                        </div>
+
+                        <div class="scene" data-scene="outro">
+                            <div class="flex flex-col items-center text-center gap-6 max-w-3xl mx-auto">
+                                <span class="badge">outro</span>
+                                <h3 data-bind="outro.title" class="text-4xl md:text-5xl font-bold">
+                                    Render from Markdown
+                                </h3>
+                                <p data-bind="outro.tagline" class="text-slate-300 text-lg md:text-xl">
+                                    Export consistent videos without ever leaving your markdown workflow.
+                                </p>
+                                <div class="flex gap-4 mt-4">
+                                    <span class="px-6 py-3 rounded-full bg-gradient-to-r from-blue-500 to-purple-600 text-white font-semibold">
+                                        Powered by Timeline Engine
+                                    </span>
+                                </div>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+            </div>
+
+            <!-- Controls -->
+            <div class="flex flex-wrap items-center gap-3">
+                <button id="syncMarkdownBtn" class="btn-secondary">
+                     Sync Markdown
+                </button>
+                <button id="presentationModeBtn" class="btn-primary">
+                     Presentation Mode
+                </button>
+                <button id="previewBtn" class="btn-primary">
+                     Preview Timeline
+                </button>
+                <button id="recordWebMBtn" class="btn-primary">
+                     Export Video
+                </button>
+                <button id="resetBtn" class="btn-secondary" title="Reset to initial state">
+                     Reset
+                </button>
+            </div>
+
+            <!-- Progress Bar -->
+            <div id="progressContainer" class="hidden">
+                <div class="progress-bar">
+                    <div id="progressBar" class="progress-bar-fill" style="width: 0%"></div>
+                </div>
+                <p id="progressText" class="text-sm text-slate-400 mt-2">Processing...</p>
+            </div>
+
+            <!-- Status Log -->
+            <div id="statusLog" class="text-sm text-slate-400 bg-slate-900/60 border border-slate-800/60 rounded-xl px-4 py-3">
+                <strong>Ready:</strong> Configure your video and click render to start.
+            </div>
+        </section>
+
+        <!-- Right Panel - Configuration -->
+        <aside class="config-panel w-full lg:w-96 xl:w-[32rem] rounded-2xl p-6 space-y-6 overflow-y-auto max-h-[92vh]">
+            <!-- Tabs -->
+            <div class="flex border-b border-slate-700">
+                <button class="tab-button" data-tab="markdown">Markdown</button>
+                <button class="tab-button" data-tab="timeline">Timeline</button>
+                <button class="tab-button" data-tab="export">Export</button>
+                <button class="tab-button" data-tab="presentation">Settings</button>
+            </div>
+
+            <!-- Tab: Markdown -->
+            <div class="tab-content active" data-tab-content="markdown">
+                <section class="space-y-4">
+                    <header>
+                        <h3 class="text-base font-semibold text-white">Markdown Deck</h3>
+                        <p class="text-xs text-slate-400 mt-1">Author your timeline, scenes, and narration directly in markdown.</p>
+                    </header>
+                    <div class="flex flex-wrap gap-2">
+                        <button id="loadMarkdownSample" class="btn-tertiary text-xs px-3 py-2">Load Sample Deck</button>
+                        <button id="importMarkdownBtn" class="btn-tertiary text-xs px-3 py-2">Import Markdown</button>
+                        <button id="openWorkspaceBtn" class="btn-tertiary text-xs px-3 py-2">Open Workspace Folder</button>
+                    </div>
+                    <label class="block">
+                        <span class="text-sm text-slate-300 mb-2 block">Markdown Source</span>
+                        <div id="markdownDropZone" class="markdown-drop-zone">
+                            <textarea id="markdownEditor" rows="18" class="w-full font-mono text-sm" placeholder="---\ntitle: Launch Update\nslides:\n  - id: intro\n    duration: 5s\n    transition: fade\n    content: |\n      # Chahua Markdown Video Studio\n      Elevate your markdown into motion\n---"></textarea>
+                            <div class="drop-overlay hidden">
+                                <div class="drop-content">
+                                    <div class="drop-icon"></div>
+                                    <div class="drop-text">Drop Markdown file here</div>
+                                    <div class="drop-hint">Supports .md, .markdown, .txt</div>
+                                </div>
+                            </div>
+                        </div>
+                    </label>
+                    <div id="markdownDiagnostics" class="hidden text-xs bg-slate-800/40 border border-slate-600/40 text-slate-300 rounded-lg p-3"></div>
+                    <div id="markdownSummary" class="text-xs text-slate-400 bg-slate-800/60 border border-slate-700/60 rounded-lg p-3">
+                        Awaiting markdown sync.
+                    </div>
+                </section>
+            </div>
+
+            <!-- Tab: Timeline -->
+            <div class="tab-content" data-tab-content="timeline">
+                <section class="space-y-4">
+                    <header>
+                        <h3 class="text-base font-semibold text-white">Timeline Overview</h3>
+                        <p class="text-xs text-slate-400 mt-1">Review parsed scenes, tracks, and media assets.</p>
+                    </header>
+                    <div class="bg-slate-900/60 border border-slate-800/60 rounded-xl p-4 space-y-3">
+                        <div class="flex items-center justify-between text-xs text-slate-400">
+                            <span>Total Duration</span>
+                            <span id="timelineTotal">00:00</span>
+                        </div>
+                        <div class="divide-y divide-slate-800" id="timelineSceneList">
+                            <div class="py-3 flex flex-col gap-1">
+                                <div class="flex items-center justify-between text-sm text-slate-200">
+                                    <span>Slide 1 · Intro</span>
+                                    <span>5s</span>
+                                </div>
+                                <p class="text-xs text-slate-500">transition: fade · narration: none</p>
+                            </div>
+                            <div class="py-3 flex flex-col gap-1">
+                                <div class="flex items-center justify-between text-sm text-slate-200">
+                                    <span>Slide 2 · Agenda</span>
+                                    <span>10s</span>
+                                </div>
+                                <p class="text-xs text-slate-500">transition: slide-left · narration: intro.mp3</p>
+                            </div>
+                        </div>
+                    </div>
+                    <section class="space-y-3">
+                        <h4 class="text-sm font-semibold text-white">Asset Checklist</h4>
+                        <ul id="assetChecklist" class="space-y-2 text-xs text-slate-400 bg-slate-900/60 border border-slate-800/60 rounded-xl p-3">
+                            <li class="flex items-center justify-between">
+                                <span>intro-bg.png</span>
+                                <span class="status-pill pending">pending</span>
+                            </li>
+                            <li class="flex items-center justify-between">
+                                <span>voiceover/intro.mp3</span>
+                                <span class="status-pill online">available</span>
+                            </li>
+                        </ul>
+                    </section>
+                </section>
+            </div>
+
+            <!-- Tab: Export -->
+            <div class="tab-content" data-tab-content="export">
+                <section class="space-y-4">
+                    <header>
+                        <h3 class="text-base font-semibold text-white">Export Settings</h3>
+                        <p class="text-xs text-slate-400 mt-1">Applied to both preview renderer and headless export jobs.</p>
+                    </header>
+                    <label class="block">
+                        <span class="text-sm text-slate-300 mb-2 block">Resolution</span>
+                        <select data-config="video.resolution" class="w-full">
+                            <option value="1920x1080">1920x1080 (Full HD)</option>
+                            <option value="1280x720">1280x720 (HD)</option>
+                            <option value="3840x2160">3840x2160 (4K)</option>
+                        </select>
+                    </label>
+                    <label class="block">
+                        <span class="text-sm text-slate-300 mb-2 block">Frame Rate (FPS)</span>
+                        <select data-config="video.fps" class="w-full">
+                            <option value="30">30 FPS</option>
+                            <option value="60" selected>60 FPS</option>
+                            <option value="120">120 FPS</option>
+                        </select>
+                    </label>
+                    <label class="block">
+                        <span class="text-sm text-slate-300 mb-2 block">Quality</span>
+                        <input type="range" min="0.1" max="1" step="0.05" data-config="video.quality" value="0.95" class="w-full">
+                        <span id="qualityValue" class="text-xs text-slate-400">95%</span>
+                    </label>
+                    <label class="block">
+                        <span class="text-sm text-slate-300 mb-2 block">Accent Color</span>
+                        <input type="color" data-config="theme.accent" value="#60a5fa" class="w-full h-12">
+                    </label>
+                    <div class="border-t border-slate-700 pt-4 space-y-3 text-xs text-slate-400">
+                        <div class="flex items-center justify-between">
+                            <span>Estimated Render Time</span>
+                            <span id="renderEta">—</span>
+                        </div>
+                        <div class="flex items-center justify-between">
+                            <span>Headless Renderer</span>
+                            <span id="rendererBackend">Pending selection</span>
+                        </div>
+                    </div>
+                </section>
+            </div>
+
+            <!-- Tab: Presentation Settings -->
+            <div class="tab-content" data-tab-content="presentation">
+                <section class="space-y-4">
+                    <header>
+                        <h3 class="text-base font-semibold text-white">Presentation Settings</h3>
+                        <p class="text-xs text-slate-400 mt-1">Configure fonts, colors, and animations. Settings are automatically saved to localStorage.</p>
+                    </header>
+
+                    <!-- Settings Legend -->
+                    <div class="bg-slate-800/30 border border-slate-700/40 rounded-lg p-3 space-y-2">
+                        <h4 class="text-xs font-semibold text-slate-200 flex items-center gap-2">
+                            <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/>
+                            </svg>
+                            Settings Legend
+                        </h4>
+                        <div class="grid grid-cols-2 gap-2 text-xs">
+                            <div class="flex items-center gap-2">
+                                <div class="w-3 h-3 bg-slate-500/50 rounded-sm"></div>
+                                <span class="text-slate-300">Slide Content</span>
+                            </div>
+                            <div class="flex items-center gap-2">
+                                <div class="w-3 h-3 bg-slate-600/50 rounded-sm"></div>
+                                <span class="text-slate-300">UI Elements</span>
+                            </div>
+                        </div>
+                        <p class="text-xs text-slate-400 pt-1">
+                            <span class="font-semibold text-slate-300">Content</span> settings affect slide content (text, headings, lists).
+                            <span class="font-semibold text-slate-300">UI</span> settings affect UI (navigation, overlays).
+                        </p>
+                    </div>
+
+                    <!-- Preset Selector -->
+                    <div class="space-y-2 pb-2">
+                        <label class="block text-sm font-medium text-slate-300">Preset</label>
+                        <select id="presetSelector" class="w-full px-3 py-2 bg-slate-900/60 border border-slate-700/60 rounded-lg text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            <option value="default">Default</option>
+                            <option value="professional">Professional</option>
+                            <option value="minimal">Minimal</option>
+                            <option value="creative">Creative</option>
+                        </select>
+                        <p class="text-xs text-slate-500">Load a preset to quickly configure all settings below.</p>
+                    </div>
+
+                    <!-- Configuration Management -->
+                    <div class="space-y-2 pb-3 border-b border-slate-800/60">
+                        <label class="block text-sm font-medium text-slate-300">Configuration</label>
+                        <div class="grid grid-cols-3 gap-2">
+                            <button id="exportConfigBtn" class="px-3 py-2 bg-slate-800/40 hover:bg-slate-700/50 border border-slate-600/40 rounded-lg text-slate-300 text-xs font-medium transition-colors flex items-center justify-center gap-2">
+                                <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-4l-4 4m0 0l-4-4m4 4V4"/>
+                                </svg>
+                                Export
+                            </button>
+                            <button id="importConfigBtn" class="px-3 py-2 bg-slate-800/40 hover:bg-slate-700/50 border border-slate-600/40 rounded-lg text-slate-300 text-xs font-medium transition-colors flex items-center justify-center gap-2">
+                                <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12"/>
+                                </svg>
+                                Import
+                            </button>
+                            <button id="resetConfigBtn" class="px-3 py-2 bg-slate-800/40 hover:bg-slate-700/50 border border-slate-600/40 rounded-lg text-slate-300 text-xs font-medium transition-colors flex items-center justify-center gap-2">
+                                <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15"/>
+                                </svg>
+                                Reset
+                            </button>
+                        </div>
+                        <p class="text-xs text-slate-500">
+                            Your settings are automatically saved to localStorage. Export creates a JSON backup file.
+                        </p>
+                    </div>
+
+                    <!-- Font Settings (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3" open>
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Fonts</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> All headings (H1-H6), body text, and code blocks in slides
+                        </p>
+                        
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Heading Font <span class="text-slate-600">(H1, H2, H3)</span></label>
+                            <select id="fontHeading" class="w-full px-3 py-2 bg-slate-900/60 border border-slate-700/60 rounded-lg text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                <!-- Options populated by JS -->
+                            </select>
+                        </div>
+
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Body Font <span class="text-slate-600">(Paragraphs, Lists)</span></label>
+                            <select id="fontBody" class="w-full px-3 py-2 bg-slate-900/60 border border-slate-700/60 rounded-lg text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                <!-- Options populated by JS -->
+                            </select>
+                        </div>
+
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Code Font <span class="text-slate-600">(Code Blocks)</span></label>
+                                <select id="fontCode" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                <!-- Options populated by JS -->
+                            </select>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Color Settings (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Colors</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Headings, links, accents, background, and all text colors in slides
+                        </p>
+                        
+                        <div class="grid grid-cols-2 gap-3">
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Primary <span class="text-slate-600">(H1, Links)</span></label>
+                                <input type="color" id="colorPrimary" class="w-full h-10 bg-slate-900/60 border border-slate-700/60 rounded-lg cursor-pointer">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Accent <span class="text-slate-600">(Highlights)</span></label>
+                                <input type="color" id="colorAccent" class="w-full h-10 bg-slate-900/60 border border-slate-700/60 rounded-lg cursor-pointer">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Background <span class="text-slate-600">(Slide BG)</span></label>
+                                <input type="color" id="colorBackground" class="w-full h-10 bg-slate-900/60 border border-slate-700/60 rounded-lg cursor-pointer">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Text <span class="text-slate-600">(Body Text)</span></label>
+                                <input type="color" id="colorText" class="w-full h-10 bg-slate-900/60 border border-slate-700/60 rounded-lg cursor-pointer">
+                            </div>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Animations (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Animations <span class="text-xs font-normal text-slate-500">(Slide Content)</span></span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Slide transitions and animation timing
+                        </p>
+                        
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Slide Transition</label>
+                            <select id="animationTransition" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                <option value="fade">Fade</option>
+                                <option value="slide">Slide</option>
+                                <option value="none">None</option>
+                            </select>
+                        </div>
+
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Duration (seconds)</label>
+                            <input type="number" id="animationDuration" min="0.1" max="2" step="0.1" value="0.6" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- UI & Visual Effects (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>UI & Visual Effects</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> UI elements (navigation, overlays, backdrops) - NOT slide content
+                        </p>
+                        <h4 class="text-sm font-semibold text-slate-300">UI & Visual Effects</h4>
+                        <p class="text-xs text-slate-500">Control overlay, navigation, and backdrop effects</p>
+                        
+                        <!-- Preview Opacity -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Preview Slide Opacity</label>
+                            <input type="number" id="previewOpacity" min="0" max="1" step="0.05" value="0.68" class="w-full px-3 py-2 bg-slate-900/60 border border-slate-700/60 rounded-lg text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            <p class="text-xs text-slate-500">Opacity of next slide preview (0-1)</p>
+                        </div>
+
+                        <!-- Overlay Settings -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Pause Overlay</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Blur (px)</label>
+                                    <input type="number" id="overlayBlur" min="0" max="20" step="1" value="8" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Border Width (px)</label>
+                                    <input type="number" id="navBorderWidth" min="1" max="5" step="1" value="2" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- Backdrop Effects -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Gradient Backdrop Effect</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Spread (%)</label>
+                                    <input type="number" id="backdropSpread" min="50" max="100" step="5" value="70" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Blur (px)</label>
+                                    <input type="number" id="backdropBlur" min="0" max="100" step="10" value="60" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Border & Accent Widths (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Border & Accent Widths</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Border thickness of headings, blockquotes, images, tables, and links in slides
+                        </p>
+                        
+                        <div class="grid grid-cols-2 gap-3">
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Heading Border</label>
+                                <input type="number" id="headingBorderWidth" min="1" max="8" step="1" value="4" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Blockquote Border</label>
+                                <input type="number" id="blockquoteBorderWidth" min="1" max="8" step="1" value="4" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Image Border</label>
+                                <input type="number" id="imageBorderWidth" min="0" max="6" step="1" value="2" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Link Underline</label>
+                                <input type="number" id="linkUnderlineWidth" min="1" max="5" step="1" value="2" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Table Border</label>
+                                <input type="number" id="tableBorderWidth" min="1" max="4" step="1" value="1" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">HR Border</label>
+                                <input type="number" id="hrBorderWidth" min="1" max="5" step="1" value="2" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Font Sizes (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Font Sizes</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> All heading and text sizes in slide content
+                        </p>
+                        <p class="text-xs text-slate-500">Adjust responsive font sizes using clamp(min, base vw, max)</p>
+                        
+                        <!-- H1 Size -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">H1 Heading (rem)</label>
+                            <div class="grid grid-cols-3 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Min</label>
+                                    <input type="number" id="fontSizeH1Min" min="1" max="5" step="0.25" value="1.75" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Base vw</label>
+                                    <input type="number" id="fontSizeH1Base" min="1" max="10" step="0.5" value="4.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Max</label>
+                                    <input type="number" id="fontSizeH1Max" min="1" max="8" step="0.25" value="3" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- H2 Size -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">H2 Heading (rem)</label>
+                            <div class="grid grid-cols-3 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Min</label>
+                                    <input type="number" id="fontSizeH2Min" min="1" max="4" step="0.25" value="1.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Base vw</label>
+                                    <input type="number" id="fontSizeH2Base" min="1" max="8" step="0.5" value="3.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Max</label>
+                                    <input type="number" id="fontSizeH2Max" min="1" max="6" step="0.25" value="2.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- Body Text Size -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Body Text (rem)</label>
+                            <div class="grid grid-cols-3 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Min</label>
+                                    <input type="number" id="fontSizeTextMin" min="0.8" max="3" step="0.1" value="1.1" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Base vw</label>
+                                    <input type="number" id="fontSizeTextBase" min="1" max="5" step="0.2" value="1.8" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Max</label>
+                                    <input type="number" id="fontSizeTextMax" min="0.8" max="4" step="0.1" value="1.6" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- Line Height -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Line Height</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Heading</label>
+                                    <input type="number" id="lineHeightHeading" min="1" max="2.5" step="0.05" value="1.3" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Body</label>
+                                    <input type="number" id="lineHeightBody" min="1" max="3" step="0.05" value="1.7" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Typography & Layout (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Typography & Layout</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Spacing, indentation, and alignment of slide content
+                        </p>
+                        <h4 class="text-sm font-semibold text-slate-300">Typography & Layout</h4>
+                        <p class="text-xs text-slate-500">Control paragraph spacing, indentation, and text alignment</p>
+                        
+                        <!-- Paragraph Spacing -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Paragraph Spacing</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Before (rem)</label>
+                                    <input type="number" id="paragraphBefore" min="0" max="3" step="0.25" value="0.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">After (rem)</label>
+                                    <input type="number" id="paragraphAfter" min="0" max="3" step="0.25" value="1" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- Heading Spacing -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Heading Spacing</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Before (rem)</label>
+                                    <input type="number" id="headingBefore" min="0" max="4" step="0.25" value="1.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">After (rem)</label>
+                                    <input type="number" id="headingAfter" min="0" max="3" step="0.25" value="0.75" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- Indentation -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Indentation (rem)</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">First Line</label>
+                                    <input type="number" id="indentFirst" min="0" max="3" step="0.25" value="0" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Blockquote</label>
+                                    <input type="number" id="indentBlockquote" min="0" max="4" step="0.25" value="1.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- List Indent & Text Align -->
+                        <div class="grid grid-cols-2 gap-3">
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">List Indent (rem)</label>
+                                <input type="number" id="listIndent" min="0" max="4" step="0.25" value="1.5" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Text Align</label>
+                                <select id="textAlign" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                    <option value="left">Left</option>
+                                    <option value="center">Center</option>
+                                    <option value="right">Right</option>
+                                    <option value="justify">Justify</option>
+                                </select>
+                            </div>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Page Indicator Settings (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Page Indicator</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Page numbers display (e.g., "1 / 3") - UI element only
+                        </p>
+                        
+                        <div class="grid grid-cols-2 gap-3">
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Position Top (px)</label>
+                                <input type="number" id="pageIndicatorTop" min="0" max="100" step="4" value="16" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Position Right (px)</label>
+                                <input type="number" id="pageIndicatorRight" min="0" max="100" step="4" value="16" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Font Size (rem)</label>
+                                <input type="number" id="pageIndicatorFontSize" min="0.5" max="2" step="0.125" value="0.875" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Opacity (0-1)</label>
+                                <input type="number" id="pageIndicatorOpacity" min="0" max="1" step="0.05" value="0.7" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Padding X (px)</label>
+                                <input type="number" id="pageIndicatorPaddingX" min="0" max="40" step="2" value="12" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">Padding Y (px)</label>
+                                <input type="number" id="pageIndicatorPaddingY" min="0" max="20" step="2" value="4" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2 col-span-2">
+                                <label class="block text-xs font-medium text-slate-400">Background Color (rgba)</label>
+                                <input type="text" id="pageIndicatorBgColor" value="rgba(22, 78, 99, 0.5)" placeholder="rgba(22, 78, 99, 0.5)" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                            </div>
+                            <div class="space-y-2 col-span-2">
+                                <label class="block text-xs font-medium text-slate-400">Text Color (hex)</label>
+                                <input type="color" id="pageIndicatorTextColor" value="#a5f3fc" class="w-full h-10 bg-slate-900/60 border border-slate-700/60 rounded cursor-pointer">
+                            </div>
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Smart List Column Settings (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Smart List Columns</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Lists in slide content - automatic column layout on large screens
+                        </p>
+                        
+                        <div class="space-y-3">
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">2-Column Threshold (items)</label>
+                                <input type="number" id="smartListTwoColumn" min="3" max="20" step="1" value="6" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                <p class="text-xs text-slate-500 mt-1">Lists with this many items or more will display in 2 columns</p>
+                            </div>
+                            <div class="space-y-2">
+                                <label class="block text-xs font-medium text-slate-400">3-Column Threshold (items)</label>
+                                <input type="number" id="smartListThreeColumn" min="6" max="30" step="1" value="12" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                <p class="text-xs text-slate-500 mt-1">Lists with this many items or more will display in 3 columns</p>
+                            </div>
+                        </div>
+                        
+                        <div class="text-xs text-slate-400 bg-slate-800/30 border border-slate-700/40 rounded-lg p-2.5 mt-3">
+                            <span class="font-semibold text-slate-300">Note:</span> Column layout only applies on large screens and in presentation mode.
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Content Layout & Positioning (Collapsible) -->
+                    <details class="settings-section border-t border-slate-800/60 pt-3">
+                        <summary class="text-sm font-semibold text-slate-300 cursor-pointer hover:text-slate-200 flex items-center gap-2 pb-3">
+                            <svg class="w-3 h-3" fill="currentColor" viewBox="0 0 20 20">
+                                <path fill-rule="evenodd" d="M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z" clip-rule="evenodd"/>
+                            </svg>
+                            <span>Content Layout & Positioning</span>
+                        </summary>
+                        <div class="space-y-3 pl-5">
+                        <p class="text-xs text-slate-500 bg-slate-800/30 border border-slate-700/40 rounded p-2">
+                            <span class="font-semibold text-slate-300">Applies to:</span> Slide content padding and alignment on different screen sizes
+                        </p>
+                        
+                        <!-- Content Padding -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Content Padding (px)</label>
+                            <div class="grid grid-cols-3 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Small</label>
+                                    <input type="number" id="contentPaddingSmall" min="0" max="100" step="4" value="40" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Large</label>
+                                    <input type="number" id="contentPaddingLarge" min="0" max="120" step="4" value="48" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Ultra</label>
+                                    <input type="number" id="contentPaddingUltra" min="0" max="150" step="4" value="64" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                </div>
+                            </div>
+                            <p class="text-xs text-slate-500 mt-1">Padding around slide content for different screen sizes</p>
+                        </div>
+
+                        <!-- Content Alignment -->
+                        <div class="space-y-2">
+                            <label class="block text-xs font-medium text-slate-400">Content Alignment</label>
+                            <div class="grid grid-cols-2 gap-2">
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Horizontal</label>
+                                    <select id="contentAlignHorizontal" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                        <option value="flex-start">Left (Start)</option>
+                                        <option value="center" selected>Center</option>
+                                        <option value="flex-end">Right (End)</option>
+                                    </select>
+                                </div>
+                                <div>
+                                    <label class="block text-xs text-slate-500 mb-1">Vertical</label>
+                                    <select id="contentAlignVertical" class="w-full px-2 py-1.5 bg-slate-900/60 border border-slate-700/60 rounded text-slate-200 text-sm focus:outline-none focus:ring-2 focus:ring-slate-500/50">
+                                        <option value="flex-start">Top (Start)</option>
+                                        <option value="center" selected>Center</option>
+                                        <option value="flex-end">Bottom (End)</option>
+                                    </select>
+                                </div>
+                            </div>
+                            <p class="text-xs text-slate-500 mt-1">How content is aligned on large screens and in presentation mode</p>
+                        </div>
+                        
+                        <div class="text-xs text-slate-400 bg-slate-800/30 border border-slate-700/40 rounded-lg p-2.5 mt-3">
+                            <span class="font-semibold text-slate-300">Tip:</span> Use center/center for traditional presentations, or flex-start/flex-start for document-style layouts.
+                        </div>
+                        </div>
+                    </details>
+
+                    <!-- Action Buttons -->
+                    <div class="flex gap-3 border-t border-slate-800/60 pt-4 mt-4">
+                        <button id="saveSettingsBtn" class="flex-1 px-4 py-2.5 bg-slate-700 hover:bg-slate-600 text-white font-medium rounded-lg transition-colors focus:outline-none focus:ring-2 focus:ring-slate-500/50 flex items-center justify-center gap-2">
+                            <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 7H5a2 2 0 00-2 2v9a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2h-3m-1 4l-3 3m0 0l-3-3m3 3V4"/>
+                            </svg>
+                            Save Settings
+                        </button>
+                        <button id="resetSettingsBtn" class="flex-1 px-4 py-2.5 bg-slate-800/50 hover:bg-slate-700/60 border border-slate-600/40 text-slate-300 font-medium rounded-lg transition-colors focus:outline-none focus:ring-2 focus:ring-slate-500/50 flex items-center justify-center gap-2">
+                            <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15"/>
+                            </svg>
+                            Reset to Default
+                        </button>
+                    </div>
+
+                    <!-- Status -->
+                    <div class="text-xs text-slate-400 bg-slate-800/30 border border-slate-700/40 rounded-lg p-3">
+                        <span class="font-semibold text-slate-300">Live Preview:</span> All changes apply <strong class="text-slate-200">instantly</strong> as you adjust settings!
+                        <br>
+                        <span class="text-slate-500 mt-1 block">Tip: Hover over any setting to see highlighted elements on stage.</span>
+                        <br>
+                        <span class="text-slate-500 mt-1 block"> Click "Save to Frontmatter" to persist settings to your markdown file.</span>
+                    </div>
+
+                    <!-- Legacy Template Support -->
+                    <details class="border-t border-slate-800/60 pt-4">
+                        <summary class="text-xs font-medium text-slate-400 cursor-pointer hover:text-slate-300">Legacy Template Support</summary>
+                        <div class="mt-3 space-y-2">
+                            <p class="text-xs text-slate-500">For backward compatibility with older decks using <code class="text-slate-400">template:</code> field.</p>
+                            <div id="templatesContainer" class="grid grid-cols-2 gap-2 mt-2"></div>
+                        </div>
+                    </details>
+                </section>
+            </div>
+        </aside>
+    </main>
+
+    <!-- External Scripts -->
+    <script type="module" src="./js/app.js"></script>
+</body>
+</html>
+

src/renderer/js/config-storage.js

@@ -0,0 +1,147 @@
+/**
+ * Configuration Storage Manager
+ * บันทึกและโหลดการตั้งค่าจาก localStorage และไฟล์ JSON
+ */
+
+const CONFIG_STORAGE_KEY = 'chahua-presentation-config';
+const CONFIG_FILE_NAME = 'presentation-config.json';
+
+export class ConfigStorage {
+    /**
+     * บันทึกการตั้งค่าลง localStorage
+     */
+    static saveToLocalStorage(config) {
+        try {
+            const configJson = JSON.stringify(config, null, 2);
+            localStorage.setItem(CONFIG_STORAGE_KEY, configJson);
+            console.log('[ConfigStorage]  Saved to localStorage');
+            return true;
+        } catch (error) {
+            console.error('[ConfigStorage] Failed to save to localStorage:', error);
+            return false;
+        }
+    }
+
+    /**
+     * โหลดการตั้งค่าจาก localStorage
+     */
+    static loadFromLocalStorage() {
+        try {
+            const configJson = localStorage.getItem(CONFIG_STORAGE_KEY);
+            if (!configJson) {
+                console.log('[ConfigStorage] No saved config in localStorage');
+                return null;
+            }
+            
+            const config = JSON.parse(configJson);
+            console.log('[ConfigStorage]  Loaded from localStorage');
+            return config;
+        } catch (error) {
+            console.error('[ConfigStorage] Failed to load from localStorage:', error);
+            return null;
+        }
+    }
+
+    /**
+     * ลบการตั้งค่าจาก localStorage
+     */
+    static clearLocalStorage() {
+        try {
+            localStorage.removeItem(CONFIG_STORAGE_KEY);
+            console.log('[ConfigStorage]  Cleared localStorage');
+            return true;
+        } catch (error) {
+            console.error('[ConfigStorage] Failed to clear localStorage:', error);
+            return false;
+        }
+    }
+
+    /**
+     * Export การตั้งค่าเป็นไฟล์ JSON
+     */
+    static async exportToFile(config, fileName = CONFIG_FILE_NAME) {
+        try {
+            const configJson = JSON.stringify(config, null, 2);
+            const blob = new Blob([configJson], { type: 'application/json' });
+            
+            // Create download link
+            const url = URL.createObjectURL(blob);
+            const a = document.createElement('a');
+            a.href = url;
+            a.download = fileName;
+            a.click();
+            
+            URL.revokeObjectURL(url);
+            console.log('[ConfigStorage]  Exported to file:', fileName);
+            return true;
+        } catch (error) {
+            console.error('[ConfigStorage] Failed to export to file:', error);
+            return false;
+        }
+    }
+
+    /**
+     * Import การตั้งค่าจากไฟล์ JSON
+     */
+    static async importFromFile() {
+        return new Promise((resolve, reject) => {
+            const input = document.createElement('input');
+            input.type = 'file';
+            input.accept = '.json';
+            
+            input.onchange = async (e) => {
+                try {
+                    const file = e.target.files[0];
+                    if (!file) {
+                        resolve(null);
+                        return;
+                    }
+                    
+                    const text = await file.text();
+                    const config = JSON.parse(text);
+                    
+                    console.log('[ConfigStorage]  Imported from file:', file.name);
+                    resolve(config);
+                } catch (error) {
+                    console.error('[ConfigStorage] Failed to import from file:', error);
+                    reject(error);
+                }
+            };
+            
+            input.click();
+        });
+    }
+
+    /**
+     * บันทึกการตั้งค่าอัตโนมัติ (debounced)
+     */
+    static autoSave(config, delay = 1000) {
+        if (this.autoSaveTimeout) {
+            clearTimeout(this.autoSaveTimeout);
+        }
+        
+        this.autoSaveTimeout = setTimeout(() => {
+            this.saveToLocalStorage(config);
+        }, delay);
+    }
+
+    /**
+     * ตรวจสอบว่ามีการตั้งค่าที่บันทึกไว้หรือไม่
+     */
+    static hasSavedConfig() {
+        return localStorage.getItem(CONFIG_STORAGE_KEY) !== null;
+    }
+
+    /**
+     * รีเซ็ตการตั้งค่าทั้งหมด
+     */
+    static reset() {
+        this.clearLocalStorage();
+        if (this.autoSaveTimeout) {
+            clearTimeout(this.autoSaveTimeout);
+        }
+    }
+}
+
+// Auto-save timeout reference
+ConfigStorage.autoSaveTimeout = null;

src/renderer/js/drag-drop-manager.js

@@ -0,0 +1,830 @@
+/**
+ * Drag & Drop Manager with Safe Zone System
+ * 
+ * จัดการการลากย้ายบรรทัดข้อความใน Presentation Mode
+ * พร้อมระบบเตือนเมื่อลากออกนอกโซนปลอดภัย
+ * 
+ * @author Chahua Development Co., Ltd.
+ * @version 2.2.0
+ */
+
+import { ContentFingerprint } from '../../shared/content-fingerprint.js';
+import { SAFE_ZONE_CONFIG, computeSafeZoneMargins, getSafeZoneConfig } from './presentation-config.js';
+
+export class DragDropManager {
+    constructor() {
+        this.isDragging = false;
+        this.currentDragElement = null;
+        this.dragStartX = 0;
+        this.dragStartY = 0;
+        this.elementStartX = 0;
+        this.elementStartY = 0;
+        this.dragOffsetX = 0;
+        this.dragOffsetY = 0;
+        
+        // Bound event handlers
+        this.boundMouseMove = null;
+        this.boundMouseUp = null;
+        
+        // Safe zone settings - อ่านจาก presentation-config.js
+        this.showSafeZone = false;
+        this.safeZoneElement = null;
+        
+        // Snap to grid
+        this.snapToGrid = false;
+        this.gridSize = 10;
+        
+        // Z-index management
+        this.maxZIndex = 1000;
+        
+        // Position storage
+        this.positions = new Map(); // fingerprint -> {x, y, zIndex, locked}
+        
+        this.init();
+    }
+
+    init() {
+        this.createSafeZoneOverlay();
+        this.setupGlobalEventListeners();
+        
+        // Listen for Safe Zone config updates
+        window.addEventListener('safeZoneConfigUpdated', () => {
+            console.log('[DragDrop] Safe Zone config updated, refreshing overlay...');
+            this.updateSafeZoneBorders();
+        });
+    }
+
+    /**
+     * สร้าง overlay แสดงโซนปลอดภัย (กรอบสีแดงบังคับ)
+     */
+    createSafeZoneOverlay() {
+        this.safeZoneElement = document.createElement('div');
+        this.safeZoneElement.className = 'safe-zone-overlay';
+        this.safeZoneElement.innerHTML = `
+            <div class="safe-zone-border safe-zone-top"></div>
+            <div class="safe-zone-border safe-zone-right"></div>
+            <div class="safe-zone-border safe-zone-bottom"></div>
+            <div class="safe-zone-border safe-zone-left"></div>
+        `;
+        document.body.appendChild(this.safeZoneElement);
+        
+        // แสดง Safe Zone ตลอดเวลาในโหมดแก้ไข
+        this.showSafeZone = true;
+    }
+
+    /**
+     * Setup global event listeners
+     */
+    setupGlobalEventListeners() {
+        // Prevent default drag behavior
+        document.addEventListener('dragstart', (e) => {
+            if (e.target.classList.contains('draggable-content')) {
+                e.preventDefault();
+            }
+        });
+    }
+
+    /**
+     * เปิดใช้งาน drag & drop สำหรับ slide ปัจจุบัน
+     * 
+     * @param {HTMLElement} sceneElement 
+     */
+    enableDragging(sceneElement) {
+        if (!sceneElement) return;
+
+        const elements = sceneElement.querySelectorAll('h1, h2, h3, h4, h5, h6, p, li, blockquote');
+        
+        elements.forEach((element, index) => {
+            this.makeDraggable(element, index);
+        });
+
+        // แสดง Safe Zone ทันทีเมื่อเข้าโหมดแก้ไข
+        this.showSafeZoneOverlay();
+        
+        // ป้องกัน click events ระหว่างลาก
+        this.preventClickPropagation = (e) => {
+            if (this.isDragging) {
+                e.stopPropagation();
+                e.preventDefault();
+            }
+        };
+        
+        sceneElement.addEventListener('click', this.preventClickPropagation, true);
+        sceneElement.addEventListener('mousedown', this.preventClickPropagation, true);
+    }
+
+    /**
+     * ปิดใช้งาน drag & drop
+     * 
+     * @param {HTMLElement} sceneElement 
+     */
+    disableDragging(sceneElement) {
+        if (!sceneElement) return;
+
+        const elements = sceneElement.querySelectorAll('.draggable-content');
+        
+        elements.forEach(element => {
+            this.makeNonDraggable(element);
+        });
+
+        this.hideSafeZoneOverlay();
+        
+        // ลบ event listeners
+        if (this.preventClickPropagation) {
+            sceneElement.removeEventListener('click', this.preventClickPropagation, true);
+            sceneElement.removeEventListener('mousedown', this.preventClickPropagation, true);
+            this.preventClickPropagation = null;
+        }
+    }
+
+    /**
+     * ทำให้ element ลากได้
+     * 
+     * @param {HTMLElement} element 
+     * @param {number} index
+     */
+    makeDraggable(element, index) {
+        // เพิ่ม class และ attributes
+        element.classList.add('draggable-content');
+        element.setAttribute('data-drag-index', index);
+        
+        // สร้าง fingerprint
+        const fingerprint = ContentFingerprint.generateStable(element);
+        element.setAttribute('data-fingerprint', fingerprint.primary);
+        
+        // โหลด position ที่บันทึกไว้
+        const savedPosition = this.positions.get(fingerprint.primary);
+        if (savedPosition) {
+            this.applyPosition(element, savedPosition);
+        } else {
+            // บันทึก position เริ่มต้น
+            this.saveInitialPosition(element, fingerprint.primary);
+        }
+        
+        // ถ้า locked ไม่ต้องเพิ่ม event listeners
+        if (savedPosition?.locked) {
+            element.classList.add('position-locked');
+            return;
+        }
+        
+        // เพิ่ม drag handle
+        this.addDragHandle(element);
+        
+        // Event listeners
+        element.addEventListener('mousedown', this.handleMouseDown.bind(this));
+    }
+
+    /**
+     * เพิ่ม drag handle (ไอคอนมือจับ)
+     * 
+     * @param {HTMLElement} element 
+     */
+    addDragHandle(element) {
+        const handle = document.createElement('div');
+        handle.className = 'drag-handle';
+        handle.innerHTML = `
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                <circle cx="9" cy="5" r="1"></circle>
+                <circle cx="9" cy="12" r="1"></circle>
+                <circle cx="9" cy="19" r="1"></circle>
+                <circle cx="15" cy="5" r="1"></circle>
+                <circle cx="15" cy="12" r="1"></circle>
+                <circle cx="15" cy="19" r="1"></circle>
+            </svg>
+        `;
+        handle.title = 'ลากเพื่อย้ายตำแหน่ง';
+        element.style.position = 'relative';
+        element.insertBefore(handle, element.firstChild);
+    }
+
+    /**
+     * ลบการ draggable
+     * 
+     * @param {HTMLElement} element 
+     */
+    makeNonDraggable(element) {
+        element.classList.remove('draggable-content', 'position-locked');
+        element.removeAttribute('data-drag-index');
+        element.removeAttribute('data-fingerprint');
+        
+        // ลบ drag handle
+        const handle = element.querySelector('.drag-handle');
+        if (handle) {
+            handle.remove();
+        }
+        
+        // ลบ event listeners
+        element.removeEventListener('mousedown', this.handleMouseDown.bind(this));
+    }
+
+    /**
+     * Handle mouse down
+     * 
+     * @param {MouseEvent} e 
+     */
+    handleMouseDown(e) {
+        // ถ้าคลิกที่ drag handle หรือ element เอง
+        const target = e.currentTarget;
+        
+        // ถ้า locked ไม่ให้ลาก
+        if (target.classList.contains('position-locked')) {
+            return;
+        }
+        
+        // เริ่ม drag
+        this.isDragging = true;
+        this.currentDragElement = target;
+        
+        // บันทึกตำแหน่งเริ่มต้น
+        this.dragStartX = e.clientX;
+        this.dragStartY = e.clientY;
+        
+        const rect = target.getBoundingClientRect();
+        this.elementStartX = rect.left;
+        this.elementStartY = rect.top;
+        this.dragOffsetX = e.clientX - rect.left;
+        this.dragOffsetY = e.clientY - rect.top;
+        
+        // เพิ่ม class
+        target.classList.add('is-dragging');
+        
+        // เพิ่ม class ให้ stage เพื่อป้องกัน select
+        const stage = document.getElementById('stage');
+        if (stage) {
+            stage.classList.add('stage-dragging');
+        }
+        
+        // Bring to front
+        this.bringToFront(target);
+        
+        // แสดง safe zone
+        if (this.showSafeZone) {
+            this.showSafeZoneOverlay();
+        }
+        
+        // Global listeners - ใช้ arrow function เพื่อรักษา context
+        this.boundMouseMove = this.handleMouseMove.bind(this);
+        this.boundMouseUp = this.handleMouseUp.bind(this);
+        
+        document.addEventListener('mousemove', this.boundMouseMove, true);
+        document.addEventListener('mouseup', this.boundMouseUp, true);
+        
+        // ป้องกันการ select text
+        e.preventDefault();
+        e.stopPropagation();
+        return false;
+    }
+
+    /**
+     * Handle mouse move
+     * 
+     * @param {MouseEvent} e 
+     */
+    handleMouseMove(e) {
+        if (!this.isDragging || !this.currentDragElement) return;
+        
+        // ป้องกันการเปลี่ยนหน้า
+        e.preventDefault();
+        e.stopPropagation();
+        
+        // คำนวณตำแหน่งใหม่ (viewport coordinates)
+        let clientX = e.clientX - this.dragOffsetX;
+        let clientY = e.clientY - this.dragOffsetY;
+        
+        // จำกัดให้อยู่ภายใน Safe Zone (ไม่ใช่แค่ stage)
+        const stage = document.getElementById('stage');
+        if (stage) {
+            const stageRect = stage.getBoundingClientRect();
+            const elementRect = this.currentDragElement.getBoundingClientRect();
+            
+            // อ่านค่า Safe Zone margins จาก stage (คำนวณจาก SMART_SAFE_ZONE แล้ว)
+            const margins = this.getSafeZoneMargins();
+            
+            // ขอบเขตของ Safe Zone (viewport coordinates)
+            const minClientX = stageRect.left + margins.left;
+            const maxClientX = stageRect.right - margins.right - elementRect.width;
+            const minClientY = stageRect.top + margins.top;
+            const maxClientY = stageRect.bottom - margins.bottom - elementRect.height;
+            
+            // จำกัดตำแหน่งให้อยู่ใน Safe Zone เท่านั้น
+            clientX = Math.max(minClientX, Math.min(clientX, maxClientX));
+            clientY = Math.max(minClientY, Math.min(clientY, maxClientY));
+        }
+        
+        // Snap to grid (ใช้ viewport coordinates)
+        if (this.snapToGrid) {
+            clientX = Math.round(clientX / this.gridSize) * this.gridSize;
+            clientY = Math.round(clientY / this.gridSize) * this.gridSize;
+        }
+        
+        // ใช้ตำแหน่งใหม่ (ใช้ fixed positioning เพื่อให้ตรงกับ clientX/Y)
+        this.currentDragElement.style.position = 'fixed';
+        this.currentDragElement.style.left = `${clientX}px`;
+        this.currentDragElement.style.top = `${clientY}px`;
+        
+        // เช็คว่าอยู่ในโซนปลอดภัยหรือไม่ (จะต้อง true เสมอเพราะเราจำกัดแล้ว)
+        const isInSafeZone = this.checkSafeZone(clientX, clientY, this.currentDragElement);
+        
+        if (!isInSafeZone) {
+            this.currentDragElement.classList.add('outside-safe-zone');
+            this.highlightSafeZoneBorder();
+        } else {
+            this.currentDragElement.classList.remove('outside-safe-zone');
+            this.unhighlightSafeZoneBorder();
+        }
+        
+        return false;
+    }
+
+    /**
+     * Handle mouse up
+     * 
+     * @param {MouseEvent} e 
+     */
+    handleMouseUp(e) {
+        if (!this.isDragging || !this.currentDragElement) return;
+        
+        // ป้องกันการเปลี่ยนหน้า
+        e.preventDefault();
+        e.stopPropagation();
+        
+        const element = this.currentDragElement;
+        
+        // ลบ class
+        element.classList.remove('is-dragging', 'outside-safe-zone');
+        this.unhighlightSafeZoneBorder();
+        
+        // ลบ class จาก stage
+        const stage = document.getElementById('stage');
+        if (stage) {
+            stage.classList.remove('stage-dragging');
+        }
+        
+        // บันทึกตำแหน่งใหม่
+        const fingerprint = element.getAttribute('data-fingerprint');
+        const rect = element.getBoundingClientRect();
+        
+        this.positions.set(fingerprint, {
+            x: rect.left,
+            y: rect.top,
+            zIndex: parseInt(element.style.zIndex) || 1000,
+            locked: false,
+            timestamp: Date.now()
+        });
+        
+        // Reset
+        this.isDragging = false;
+        this.currentDragElement = null;
+        
+        // ลบ global listeners - ใช้ bound functions
+        if (this.boundMouseMove) {
+            document.removeEventListener('mousemove', this.boundMouseMove, true);
+            this.boundMouseMove = null;
+        }
+        if (this.boundMouseUp) {
+            document.removeEventListener('mouseup', this.boundMouseUp, true);
+            this.boundMouseUp = null;
+        }
+        
+        // ซ่อน safe zone ถ้าไม่ได้เปิดค้างไว้
+        if (!this.showSafeZone) {
+            this.hideSafeZoneOverlay();
+        }
+        
+        // Trigger save event
+        this.dispatchPositionChanged(fingerprint);
+        
+        return false;
+    }
+
+    /**
+     * อ่านค่า Safe Zone margins จาก presentation-config.js
+     * 
+     * @returns {Object} { top, right, bottom, left }
+     */
+    getSafeZoneMargins() {
+        const stage = document.getElementById('stage');
+        if (!stage) {
+            // ใช้ค่าจาก config
+            return computeSafeZoneMargins();
+        }
+        
+        const stageRect = stage.getBoundingClientRect();
+        return computeSafeZoneMargins(stageRect);
+    }
+
+    /**
+     * เช็คว่าอยู่ในโซนปลอดภัยหรือไม่
+     * 
+     * @param {number} x 
+     * @param {number} y 
+     * @param {HTMLElement} element 
+     * @returns {boolean}
+     */
+    checkSafeZone(x, y, element) {
+        // ใช้ stage เป็นขอบเขต
+        const stage = document.getElementById('stage');
+        if (!stage) return true;
+        
+        const stageRect = stage.getBoundingClientRect();
+        const elementRect = element.getBoundingClientRect();
+        const width = elementRect.width;
+        const height = elementRect.height;
+        
+        // อ่านค่า Safe Zone margins จาก stage
+        const margins = this.getSafeZoneMargins();
+        
+        // คำนวณจากขอบ stage
+        const minX = stageRect.left + margins.left;
+        const maxX = stageRect.right - margins.right - width;
+        const minY = stageRect.top + margins.top;
+        const maxY = stageRect.bottom - margins.bottom - height;
+        
+        // เช็คว่าอยู่ในโซนหรือไม่
+        const inHorizontal = (x >= minX) && (x <= maxX);
+        const inVertical = (y >= minY) && (y <= maxY);
+        
+        return inHorizontal && inVertical;
+    }
+
+    /**
+     * แสดง safe zone overlay
+     */
+    showSafeZoneOverlay() {
+        if (!this.safeZoneElement) {
+            console.warn('[DragDrop] Safe zone element not found');
+            return;
+        }
+        
+        this.safeZoneElement.classList.remove('hidden');
+        this.updateSafeZoneBorders();
+        console.log('[DragDrop] Safe zone overlay shown');
+    }
+
+    /**
+     * ซ่อน safe zone overlay
+     */
+    hideSafeZoneOverlay() {
+        if (!this.safeZoneElement) return;
+        this.safeZoneElement.classList.add('hidden');
+        console.log('[DragDrop] Safe zone overlay hidden');
+    }
+
+    /**
+     * อัปเดต safe zone borders (ตาม stage)
+     */
+    updateSafeZoneBorders() {
+        if (!this.safeZoneElement) {
+            console.warn('[DragDrop] Cannot update borders: safeZoneElement is null');
+            return;
+        }
+        
+        // ใช้ stage เป็นขอบเขต
+        const stage = document.getElementById('stage');
+        if (!stage) {
+            console.warn('[DragDrop] Cannot update borders: stage not found');
+            return;
+        }
+        
+        const stageRect = stage.getBoundingClientRect();
+        // อ่านค่า Safe Zone margins จาก stage
+        const margins = this.getSafeZoneMargins();
+        
+        console.log('[DragDrop] Updating Safe Zone borders:', {
+            stageRect: { width: stageRect.width, height: stageRect.height, left: stageRect.left, top: stageRect.top },
+            margins: margins,
+            viewportSize: { width: window.innerWidth, height: window.innerHeight }
+        });
+        
+        // คำนวณตำแหน่งจาก stage (ใช้ margins แยกแต่ละด้าน)
+        const topPos = stageRect.top + margins.top;
+        const rightPos = stageRect.right - margins.right;
+        const bottomPos = stageRect.bottom - margins.bottom;
+        const leftPos = stageRect.left + margins.left;
+        
+        // อ่านค่าจาก config
+        const borderConfig = SAFE_ZONE_CONFIG.border;
+        
+        // Top border
+        const top = this.safeZoneElement.querySelector('.safe-zone-top');
+        if (top) {
+            top.style.position = 'fixed';
+            top.style.top = `${topPos}px`;
+            top.style.left = `${leftPos}px`;
+            top.style.width = `${stageRect.width - margins.left - margins.right}px`;
+            top.style.height = `${borderConfig.width}px`;
+            top.style.backgroundColor = borderConfig.color;
+            top.style.boxShadow = `0 0 ${borderConfig.glowSize} ${borderConfig.glowColor}`;
+            top.style.zIndex = borderConfig.zIndex;
+            top.style.pointerEvents = 'none';
+        }
+        
+        // Right border
+        const right = this.safeZoneElement.querySelector('.safe-zone-right');
+        if (right) {
+            right.style.position = 'fixed';
+            right.style.top = `${topPos}px`;
+            right.style.left = `${rightPos}px`;
+            right.style.height = `${stageRect.height - margins.top - margins.bottom}px`;
+            right.style.width = `${borderConfig.width}px`;
+            right.style.backgroundColor = borderConfig.color;
+            right.style.boxShadow = `0 0 ${borderConfig.glowSize} ${borderConfig.glowColor}`;
+            right.style.zIndex = borderConfig.zIndex;
+            right.style.pointerEvents = 'none';
+        }
+        
+        // Bottom border
+        const bottom = this.safeZoneElement.querySelector('.safe-zone-bottom');
+        if (bottom) {
+            bottom.style.position = 'fixed';
+            bottom.style.top = `${bottomPos}px`;
+            bottom.style.left = `${leftPos}px`;
+            bottom.style.width = `${stageRect.width - margins.left - margins.right}px`;
+            bottom.style.height = `${borderConfig.width}px`;
+            bottom.style.backgroundColor = borderConfig.color;
+            bottom.style.boxShadow = `0 0 ${borderConfig.glowSize} ${borderConfig.glowColor}`;
+            bottom.style.zIndex = borderConfig.zIndex;
+            bottom.style.pointerEvents = 'none';
+        }
+        
+        // Left border
+        const left = this.safeZoneElement.querySelector('.safe-zone-left');
+        if (left) {
+            left.style.position = 'fixed';
+            left.style.top = `${topPos}px`;
+            left.style.left = `${leftPos}px`;
+            left.style.height = `${stageRect.height - margins.top - margins.bottom}px`;
+            left.style.width = `${borderConfig.width}px`;
+            left.style.backgroundColor = borderConfig.color;
+            left.style.boxShadow = `0 0 ${borderConfig.glowSize} ${borderConfig.glowColor}`;
+            left.style.zIndex = borderConfig.zIndex;
+            left.style.pointerEvents = 'none';
+        }
+        
+        console.log('[DragDrop] Safe Zone borders updated successfully');
+    }
+    
+    /**
+     * อัปเดต corners ของ safe zone
+     */
+    updateSafeZoneCorners(stageRect, margins) {
+        if (!this.safeZoneElement) return;
+        
+        const topPos = stageRect.top + margins.top;
+        const rightPos = stageRect.right - margins.right;
+        const bottomPos = stageRect.bottom - margins.bottom;
+        const leftPos = stageRect.left + margins.left;
+        
+        // Top-left
+        const tl = this.safeZoneElement.querySelector('.safe-zone-tl');
+        if (tl) {
+            tl.style.position = 'fixed';
+            tl.style.top = `${topPos}px`;
+            tl.style.left = `${leftPos}px`;
+        }
+        
+        // Top-right
+        const tr = this.safeZoneElement.querySelector('.safe-zone-tr');
+        if (tr) {
+            tr.style.position = 'fixed';
+            tr.style.top = `${topPos}px`;
+            tr.style.left = `${rightPos - 20}px`;
+        }
+        
+        // Bottom-right
+        const br = this.safeZoneElement.querySelector('.safe-zone-br');
+        if (br) {
+            br.style.position = 'fixed';
+            br.style.top = `${bottomPos - 20}px`;
+            br.style.left = `${rightPos - 20}px`;
+        }
+        
+        // Bottom-left
+        const bl = this.safeZoneElement.querySelector('.safe-zone-bl');
+        if (bl) {
+            bl.style.position = 'fixed';
+            bl.style.top = `${bottomPos - 20}px`;
+            bl.style.left = `${leftPos}px`;
+        }
+    }
+
+    /**
+     * Highlight safe zone border (เตือนสีแดง)
+     */
+    highlightSafeZoneBorder() {
+        if (!this.safeZoneElement) return;
+        this.safeZoneElement.classList.add('warning');
+    }
+
+    /**
+     * Unhighlight safe zone border
+     */
+    unhighlightSafeZoneBorder() {
+        if (!this.safeZoneElement) return;
+        this.safeZoneElement.classList.remove('warning');
+    }
+
+    /**
+     * Bring element to front
+     * 
+     * @param {HTMLElement} element 
+     */
+    bringToFront(element) {
+        this.maxZIndex++;
+        element.style.zIndex = this.maxZIndex;
+    }
+
+    /**
+     * บันทึก initial position
+     * 
+     * @param {HTMLElement} element 
+     * @param {string} fingerprint 
+     */
+    saveInitialPosition(element, fingerprint) {
+        // ตั้ง position เป็น fixed (ใช้ viewport coordinates)
+        const computedStyle = window.getComputedStyle(element);
+        if (computedStyle.position !== 'fixed' && computedStyle.position !== 'absolute') {
+            element.style.position = 'fixed';
+        }
+        
+        const rect = element.getBoundingClientRect();
+        
+        this.positions.set(fingerprint, {
+            x: rect.left,
+            y: rect.top,
+            zIndex: 1000,
+            locked: false,
+            timestamp: Date.now()
+        });
+    }
+
+    /**
+     * Apply position to element
+     * 
+     * @param {HTMLElement} element 
+     * @param {Object} position 
+     */
+    applyPosition(element, position) {
+        // ใช้ fixed positioning เพื่อให้ตำแหน่งตรงกับที่บ���นทึกไว้
+        element.style.position = 'fixed';
+        element.style.left = `${position.x}px`;
+        element.style.top = `${position.y}px`;
+        element.style.zIndex = position.zIndex || 1000;
+        
+        if (position.locked) {
+            element.classList.add('position-locked');
+        }
+    }
+
+    /**
+     * Lock/unlock element position
+     * 
+     * @param {HTMLElement} element 
+     * @param {boolean} locked 
+     */
+    toggleLock(element, locked) {
+        const fingerprint = element.getAttribute('data-fingerprint');
+        if (!fingerprint) return;
+        
+        const position = this.positions.get(fingerprint);
+        if (position) {
+            position.locked = locked;
+            this.positions.set(fingerprint, position);
+        }
+        
+        if (locked) {
+            element.classList.add('position-locked');
+            this.makeNonDraggable(element);
+        } else {
+            element.classList.remove('position-locked');
+            const index = parseInt(element.getAttribute('data-drag-index'));
+            this.makeDraggable(element, index);
+        }
+    }
+
+    /**
+     * Reset position to original
+     * 
+     * @param {HTMLElement} element 
+     */
+    resetPosition(element) {
+        const fingerprint = element.getAttribute('data-fingerprint');
+        if (!fingerprint) return;
+        
+        // ลบ position
+        this.positions.delete(fingerprint);
+        
+        // Reset styles
+        element.style.position = '';
+        element.style.left = '';
+        element.style.top = '';
+        element.style.zIndex = '';
+        
+        this.dispatchPositionChanged(fingerprint);
+    }
+
+    /**
+     * Get all positions
+     * 
+     * @returns {Map}
+     */
+    getAllPositions() {
+        return this.positions;
+    }
+
+    /**
+     * Load positions from storage
+     * 
+     * @param {Object} savedPositions 
+     */
+    loadPositions(savedPositions) {
+        if (!savedPositions) return;
+        
+        this.positions = new Map(Object.entries(savedPositions));
+    }
+
+    /**
+     * Export positions
+     * 
+     * @returns {Object}
+     */
+    exportPositions() {
+        return Object.fromEntries(this.positions);
+    }
+
+    /**
+     * Clear all positions
+     */
+    clearAllPositions() {
+        this.positions.clear();
+    }
+
+    /**
+     * Dispatch position changed event
+     * 
+     * @param {string} fingerprint 
+     */
+    dispatchPositionChanged(fingerprint) {
+        const event = new CustomEvent('positionChanged', {
+            detail: {
+                fingerprint,
+                position: this.positions.get(fingerprint)
+            }
+        });
+        document.dispatchEvent(event);
+    }
+
+    /**
+     * Toggle safe zone visibility
+     * 
+     * @param {boolean} show 
+     */
+    toggleSafeZone(show) {
+        this.showSafeZone = show;
+        if (show) {
+            this.showSafeZoneOverlay();
+        } else {
+            this.hideSafeZoneOverlay();
+        }
+    }
+
+    /**
+     * Set safe zone margin
+     * 
+     * @param {number} margin - pixels
+     */
+    setSafeZoneMargin(margin) {
+        this.safeZoneMargin = margin;
+        this.updateSafeZoneBorders();
+    }
+
+    /**
+     * Toggle snap to grid
+     * 
+     * @param {boolean} enabled 
+     */
+    toggleSnapToGrid(enabled) {
+        this.snapToGrid = enabled;
+    }
+
+    /**
+     * Set grid size
+     * 
+     * @param {number} size - pixels
+     */
+    setGridSize(size) {
+        this.gridSize = size;
+    }
+
+    /**
+     * Cleanup
+     */
+    destroy() {
+        if (this.safeZoneElement) {
+            this.safeZoneElement.remove();
+        }
+        this.positions.clear();
+    }
+}
+
+export default DragDropManager;

src/renderer/js/mode-manager.js

@@ -0,0 +1,459 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Mode Manager - Strict Mode Separation System
+// แยกโหมดการทำงานแบบเด็ดขาด ไม่ให้ทับซ้อนกัน
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { setDisplayMode } from './presentation-config.js';
+
+/**
+ * Mode Manager Class
+ * ควบคุมโหมดการทำงานทั้งหมด แยกอย่างเด็ดขาด
+ */
+export class ModeManager {
+  constructor() {
+    this.currentMode = 'intro';
+    this.modes = {
+      intro: null,
+      presentation: null,
+      editor: null
+    };
+    
+    // Track all active systems
+    this.activeSystems = {
+      smartLayout: false,
+      dragDrop: false,
+      contentEditable: false,
+      resizeObserver: false,
+      keyboardNav: false,
+      safeZoneBorder: false
+    };
+    
+    // System references
+    this.systems = {
+      smartLayoutControl: null,
+      dragDropManager: null,
+      resizeObserver: null,
+      eventListeners: []
+    };
+    
+    console.log('[ModeManager] Initialized');
+  }
+
+  /**
+   * Switch to a specific mode (EXCLUSIVE - ปิดโหมดอื่นทั้งหมด)
+   */
+  switchMode(newMode) {
+    if (!['intro', 'presentation', 'editor'].includes(newMode)) {
+      console.error(`[ModeManager] Invalid mode: ${newMode}`);
+      return false;
+    }
+
+    if (this.currentMode === newMode) {
+      console.log(`[ModeManager] Already in ${newMode} mode`);
+      return true;
+    }
+
+    console.log(`[ModeManager]  SWITCHING: ${this.currentMode} → ${newMode}`);
+
+    // 1. SHUTDOWN current mode completely
+    this.shutdownMode(this.currentMode);
+
+    // 2. UPDATE mode
+    this.currentMode = newMode;
+    setDisplayMode(newMode);
+
+    // 3. ACTIVATE new mode exclusively
+    this.activateMode(newMode);
+
+    // 4. Dispatch event
+    window.dispatchEvent(new CustomEvent('modeChanged', {
+      detail: { 
+        mode: newMode,
+        timestamp: Date.now()
+      }
+    }));
+
+    console.log(`[ModeManager]  Now in ${newMode} mode (ALL OTHER MODES DISABLED)`);
+    return true;
+  }
+
+  /**
+   * Shutdown a mode completely (ปิดทุกระบบในโหมดนั้น)
+   */
+  shutdownMode(mode) {
+    console.log(`[ModeManager]  Shutting down ${mode} mode...`);
+
+    switch (mode) {
+      case 'intro':
+        this.shutdownIntroMode();
+        break;
+      case 'presentation':
+        this.shutdownPresentationMode();
+        break;
+      case 'editor':
+        this.shutdownEditorMode();
+        break;
+    }
+
+    console.log(`[ModeManager] ${mode} mode shut down completely`);
+  }
+
+  /**
+   * Activate a mode exclusively (เปิดเฉพาะระบบในโหมดนั้น)
+   */
+  activateMode(mode) {
+    console.log(`[ModeManager]  Activating ${mode} mode...`);
+
+    switch (mode) {
+      case 'intro':
+        this.activateIntroMode();
+        break;
+      case 'presentation':
+        this.activatePresentationMode();
+        break;
+      case 'editor':
+        this.activateEditorMode();
+        break;
+    }
+
+    console.log(`[ModeManager] ${mode} mode activated exclusively`);
+  }
+
+  // ═══════════════════════════════════════════════════════════════════════
+  // INTRO MODE - เฉพาะหน้า Intro
+  // ═══════════════════════════════════════════════════════════════════════
+
+  activateIntroMode() {
+    // Intro mode: ไม่มีระบบอะไรทำงานเลย เป็นหน้าคงที่
+    this.disableAllSystems();
+    
+    // ปิด Smart Layout อย่างเด็ดขาด
+    if (window.smartLayoutControl) {
+      window.smartLayoutControl.detach();
+    }
+
+    //  ซ่อน UI ของโหมดอื่นทั้งหมด
+    this.hideAllModeUI();
+
+    // แสดงเฉพาะ intro scene
+    const scenes = document.querySelectorAll('[data-scene]');
+    scenes.forEach(scene => {
+      if (scene.dataset.scene === 'intro') {
+        scene.classList.add('active');
+      } else {
+        scene.classList.remove('active');
+      }
+    });
+
+    console.log('[ModeManager] Intro mode: Static display only (no systems)');
+  }
+
+  shutdownIntroMode() {
+    // Intro ไม่มีอะไรต้องปิด
+    console.log('[ModeManager] Intro mode: No systems to shutdown');
+  }
+
+  // ═══════════════════════════════════════════════════════════════════════
+  // PRESENTATION MODE - สำหรับนำเสนอเท่านั้น
+  // ═══════════════════════════════════════════════════════════════════════
+
+  activatePresentationMode() {
+    // ปิดทุกระบบก่อน
+    this.disableAllSystems();
+
+    // เปิดเฉพาะ Keyboard Navigation
+    this.activeSystems.keyboardNav = true;
+
+    //  เปิด Smart Layout เฉพาะ Presentation Mode
+    this.activeSystems.smartLayout = true;
+    
+    //  Reattach Smart Layout observers สำหรับ Presentation
+    if (window.smartLayoutControl) {
+      this.systems.smartLayoutControl = window.smartLayoutControl;
+      window.smartLayoutControl.reattach();
+    }
+    
+    // ปิด Safe Zone Border
+    this.activeSystems.safeZoneBorder = false;
+
+    //  แสดงเฉพาะ UI ของ Presentation Mode
+    this.showPresentationUI();
+
+    console.log('[ModeManager] Presentation mode: Keyboard nav + Smart Layout ENABLED');
+  }
+
+  shutdownPresentationMode() {
+    // ปิด Keyboard Navigation
+    this.activeSystems.keyboardNav = false;
+
+    // ปิด Smart Layout และ detach observers
+    this.activeSystems.smartLayout = false;
+    if (window.smartLayoutControl) {
+      window.smartLayoutControl.detach();
+    }
+
+    // ✅ ซ่อน UI ของ Presentation Mode
+    this.hideAllModeUI();
+
+    console.log('[ModeManager] Presentation mode: Shut down');
+  }
+
+  // ═══════════════════════════════════════════════════════════════════════
+  // EDITOR MODE - สำหรับแก้ไข/ลากย้ายเท่านั้น
+  // ═══════════════════════════════════════════════════════════════════════
+
+  activateEditorMode() {
+    // ปิดทุกระบบก่อน
+    this.disableAllSystems();
+
+    // เปิด Content Editable
+    this.activeSystems.contentEditable = true;
+
+    // เปิด Drag & Drop
+    this.activeSystems.dragDrop = true;
+
+    // เปิด Safe Zone Border (กรอบสีแดง)
+    this.activeSystems.safeZoneBorder = true;
+    this.showSafeZoneBorder();
+
+    // ปิด Smart Layout อย่างเด็ดขาด (ห้ามทำงานใน Editor Mode)
+    this.activeSystems.smartLayout = false;
+    if (window.smartLayoutControl) {
+      window.smartLayoutControl.detach();
+    }
+
+    // ปิด Resize Observer
+    this.activeSystems.resizeObserver = false;
+
+    //  แสดงเฉพาะ UI ของ Editor Mode
+    this.showEditorUI();
+
+    console.log('[ModeManager] Editor mode: Edit/Drag only (Smart Layout DISABLED)');
+  }
+
+  shutdownEditorMode() {
+    // ปิด Content Editable
+    this.activeSystems.contentEditable = false;
+    this.disableContentEditable();
+
+    // ปิด Drag & Drop
+    this.activeSystems.dragDrop = false;
+
+    // ปิด Safe Zone Border
+    this.activeSystems.safeZoneBorder = false;
+    this.hideSafeZoneBorder();
+
+    // ✅ ซ่อน UI ของ Editor Mode
+    this.hideAllModeUI();
+
+    console.log('[ModeManager] Editor mode: Shut down');
+  }
+
+  // ═══════════════════════════════════════════════════════════════════════
+  // SYSTEM CONTROL - ควบคุมระบบย่อยๆ
+  // ═══════════════════════════════════════════════════════════════════════
+
+  /**
+   * ปิดทุกระบบ (ไม่ต้อง detach Smart Layout เพราะแต่ละโหมดจัดการเอง)
+   */
+  disableAllSystems() {
+    // ไม่ detach Smart Layout ที่นี่ ให้แต่ละโหมดจัดการเอง
+    
+    // ปิด Content Editable
+    this.disableContentEditable();
+
+    // ซ่อน Safe Zone Border
+    this.hideSafeZoneBorder();
+
+    // รีเซ็ต active systems
+    Object.keys(this.activeSystems).forEach(key => {
+      this.activeSystems[key] = false;
+    });
+
+    console.log('[ModeManager] All systems disabled (except Smart Layout - handled per mode)');
+  }
+
+  /**
+   * ปิด Content Editable ทุกอัน
+   */
+  disableContentEditable() {
+    const editables = document.querySelectorAll('[contenteditable="true"]');
+    editables.forEach(el => {
+      el.contentEditable = false;
+      el.blur();
+    });
+
+    // ลบ class editable
+    const stage = document.getElementById('stage');
+    if (stage) {
+      stage.classList.remove('slide-editable');
+    }
+  }
+
+  /**
+   * ซ่อน Safe Zone Border
+   */
+  hideSafeZoneBorder() {
+    const safeZone = document.querySelector('.safe-zone-overlay');
+    if (safeZone) {
+      safeZone.classList.add('hidden');
+    }
+  }
+
+  /**
+   * แสดง Safe Zone Border
+   */
+  showSafeZoneBorder() {
+    const safeZone = document.querySelector('.safe-zone-overlay');
+    if (safeZone) {
+      safeZone.classList.remove('hidden');
+    }
+  }
+
+  /**
+   * Get current mode
+   */
+  getCurrentMode() {
+    return this.currentMode;
+  }
+
+  /**
+   * Check if specific system is active
+   */
+  isSystemActive(systemName) {
+    return this.activeSystems[systemName] || false;
+  }
+
+  /**
+   * Get all active systems
+   */
+  getActiveSystems() {
+    return Object.entries(this.activeSystems)
+      .filter(([key, value]) => value)
+      .map(([key]) => key);
+  }
+
+  /**
+   * Register system reference
+   */
+  registerSystem(name, reference) {
+    this.systems[name] = reference;
+    console.log(`[ModeManager] Registered system: ${name}`);
+  }
+
+  // ═══════════════════════════════════════════════════════════════════════
+  // UI CONTROL - ควบคุม UI elements ของแต่ละโหมด
+  // ═══════════════════════════════════════════════════════════════════════
+
+  /**
+   * ซ่อน UI ของทุกโหมด
+   */
+  hideAllModeUI() {
+    // Presentation Mode UI
+    const navControls = document.getElementById('navControls');
+    const exitPresentationBtn = document.getElementById('exitPresentationBtn');
+    const fullscreenBtn = document.getElementById('fullscreenBtn');
+    const editSlideBtn = document.getElementById('editSlideBtn');
+
+    if (navControls) navControls.classList.add('hidden');
+    if (exitPresentationBtn) exitPresentationBtn.classList.add('hidden');
+    if (fullscreenBtn) fullscreenBtn.classList.add('hidden');
+    if (editSlideBtn) editSlideBtn.classList.add('hidden');
+
+    // Editor Mode UI
+    const saveSlideBtn = document.getElementById('saveSlideBtn');
+    const cancelEditBtn = document.getElementById('cancelEditBtn');
+    
+    if (saveSlideBtn) saveSlideBtn.classList.add('hidden');
+    if (cancelEditBtn) cancelEditBtn.classList.add('hidden');
+
+    console.log('[ModeManager] All mode UI hidden');
+  }
+
+  /**
+   * แสดง UI ของ Presentation Mode เท่านั้น
+   */
+  showPresentationUI() {
+    this.hideAllModeUI();
+
+    const navControls = document.getElementById('navControls');
+    const exitPresentationBtn = document.getElementById('exitPresentationBtn');
+    const fullscreenBtn = document.getElementById('fullscreenBtn');
+    const editSlideBtn = document.getElementById('editSlideBtn');
+
+    if (navControls) navControls.classList.remove('hidden');
+    if (exitPresentationBtn) exitPresentationBtn.classList.remove('hidden');
+    if (fullscreenBtn) fullscreenBtn.classList.remove('hidden');
+    if (editSlideBtn) editSlideBtn.classList.remove('hidden');
+
+    console.log('[ModeManager] Presentation UI shown exclusively');
+  }
+
+  /**
+   * แสดง UI ของ Editor Mode เท่านั้น
+   */
+  showEditorUI() {
+    this.hideAllModeUI();
+
+    const saveSlideBtn = document.getElementById('saveSlideBtn');
+    const cancelEditBtn = document.getElementById('cancelEditBtn');
+    const exitPresentationBtn = document.getElementById('exitPresentationBtn');
+
+    if (saveSlideBtn) saveSlideBtn.classList.remove('hidden');
+    if (cancelEditBtn) cancelEditBtn.classList.remove('hidden');
+    if (exitPresentationBtn) exitPresentationBtn.classList.remove('hidden');
+
+    console.log('[ModeManager] Editor UI shown exclusively');
+  }
+
+  /**
+   * Force shutdown all (emergency)
+   */
+  emergencyShutdown() {
+    console.warn('[ModeManager]  EMERGENCY SHUTDOWN');
+    this.disableAllSystems();
+    
+    // Stop all observers
+    if (this.systems.resizeObserver) {
+      this.systems.resizeObserver.disconnect();
+    }
+
+    // Remove all event listeners
+    this.systems.eventListeners.forEach(({ element, event, handler }) => {
+      element.removeEventListener(event, handler);
+    });
+    this.systems.eventListeners = [];
+
+    console.log('[ModeManager] Emergency shutdown complete');
+  }
+}
+
+// Singleton instance
+let modeManagerInstance = null;
+
+/**
+ * Get Mode Manager instance (Singleton)
+ */
+export function getModeManager() {
+  if (!modeManagerInstance) {
+    modeManagerInstance = new ModeManager();
+  }
+  return modeManagerInstance;
+}
+
+/**
+ * Quick access functions
+ */
+export function switchToIntroMode() {
+  return getModeManager().switchMode('intro');
+}
+
+export function switchToPresentationMode() {
+  return getModeManager().switchMode('presentation');
+}
+
+export function switchToEditorMode() {
+  return getModeManager().switchMode('editor');
+}
+
+export default ModeManager;

src/renderer/js/presentation-config.js

@@ -0,0 +1,2066 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Presentation Configuration System
+// Flexible Configuration Instead of Fixed Templates
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 2.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { ConfigStorage } from './config-storage.js';
+
+// ════════════════════════════════════════════════════════════════════════════
+// DISPLAY MODE DETECTION (ตรวจสอบโหมดการแสดงผลปัจจุบัน)
+// ════════════════════════════════════════════════════════════════════════════
+
+let currentDisplayMode = 'intro'; // 'intro', 'editor', 'presentation'
+
+/**
+ * Set current display mode
+ * @param {string} mode - 'intro' | 'editor' | 'presentation'
+ */
+export function setDisplayMode(mode) {
+  const validModes = ['intro', 'editor', 'presentation'];
+  if (!validModes.includes(mode)) {
+    console.warn(`[PresentationConfig] Invalid mode: ${mode}, using 'intro'`);
+    mode = 'intro';
+  }
+  
+  currentDisplayMode = mode;
+  console.log(`[PresentationConfig] Display mode set to: ${mode}`);
+  
+  // Trigger event for other systems to respond
+  window.dispatchEvent(new CustomEvent('displayModeChanged', {
+    detail: { mode }
+  }));
+}
+
+/**
+ * Get current display mode
+ * @returns {string}
+ */
+export function getDisplayMode() {
+  return currentDisplayMode;
+}
+
+// ════════════════════════════════════════════════════════════════════════════
+// Safe Zone Configuration (แยกตามโหมดการแสดงผล 3 ชุด)
+// ════════════════════════════════════════════════════════════════════════════
+
+/**
+ * INTRO MODE - Safe Zone for intro scene (hard-coded values)
+ * ใช้สำหรับหน้า Intro เท่านั้น ค่าคงที่
+ */
+export const INTRO_SAFE_ZONE_CONFIG = {
+  margins: {
+    horizontalRatio: 0.08,      // 8% ของความกว้าง (กว้างกว่าโหมดอื่น)
+    verticalRatio: 0.10,        // 10% ของความสูง (สูงกว่าโหมดอื่น)
+    maxHorizontalRatio: 0.15,
+    maxVerticalRatio: 0.18,
+    minHorizontal: 60,          // ขั้นต่ำสูงกว่า
+    minVertical: 60
+  },
+  border: {
+    enabled: false,             // ไม่แสดงกรอบใน Intro
+    color: 'rgba(100, 116, 139, 0.3)',
+    width: 1,
+    glowColor: 'rgba(100, 116, 139, 0.2)',
+    glowSize: '2px',
+    zIndex: 1000
+  },
+  enforcement: {
+    enabled: false,             // ไม่บังคับใน Intro
+    snapToEdge: false,
+    showWarning: false
+  }
+};
+
+/**
+ * EDITOR MODE - Safe Zone for edit/drag mode (strict enforcement)
+ * ใช้สำหรับโหมดแก้ไข/ลาก มีกรอบสีแดงบังคับ
+ */
+export const EDITOR_SAFE_ZONE_CONFIG = {
+  margins: {
+    horizontalRatio: 0.06,      // 6% ของความกว้าง
+    verticalRatio: 0.08,        // 8% ของความสูง
+    maxHorizontalRatio: 0.12,
+    maxVerticalRatio: 0.15,
+    minHorizontal: 40,
+    minVertical: 40
+  },
+  border: {
+    enabled: true,              // แสดงกรอบสีแดง
+    color: 'rgba(239, 68, 68, 0.8)',
+    width: 2,                   // หนากว่าโหมดอื่น
+    glowColor: 'rgba(239, 68, 68, 0.5)',
+    glowSize: '6px',
+    zIndex: 9999                // อยู่บนสุด
+  },
+  enforcement: {
+    enabled: true,              // บังคับไม่ให้ลากออก
+    snapToEdge: true,
+    showWarning: true
+  }
+};
+
+/**
+ * PRESENTATION MODE - Safe Zone for presentation (visual guide only)
+ * ใช้สำหรับโหมดนำเสนอ แสดงกรอบบางๆ เป็นแนวทาง
+ */
+export const PRESENTATION_SAFE_ZONE_CONFIG = {
+  margins: {
+    horizontalRatio: 0.05,      // 5% ของความกว้าง (น้อยที่สุด)
+    verticalRatio: 0.07,        // 7% ของความสูง
+    maxHorizontalRatio: 0.10,
+    maxVerticalRatio: 0.12,
+    minHorizontal: 30,
+    minVertical: 30
+  },
+  border: {
+    enabled: false,             // ไม่แสดงกรอบในการนำเสนอปกติ
+    color: 'rgba(100, 116, 139, 0.2)',
+    width: 1,
+    glowColor: 'rgba(100, 116, 139, 0.1)',
+    glowSize: '2px',
+    zIndex: 100
+  },
+  enforcement: {
+    enabled: false,             // ไม่บังคับ
+    snapToEdge: false,
+    showWarning: false
+  }
+};
+
+/**
+ * Get Safe Zone Config based on current display mode
+ * @returns {Object} Safe Zone configuration for current mode
+ */
+export function getSafeZoneConfig() {
+  switch (currentDisplayMode) {
+    case 'intro':
+      return { ...INTRO_SAFE_ZONE_CONFIG };
+    case 'editor':
+      return { ...EDITOR_SAFE_ZONE_CONFIG };
+    case 'presentation':
+      return { ...PRESENTATION_SAFE_ZONE_CONFIG };
+    default:
+      console.warn(`[PresentationConfig] Unknown mode: ${currentDisplayMode}, using editor config`);
+      return { ...EDITOR_SAFE_ZONE_CONFIG };
+  }
+}
+
+/**
+ * Legacy export for backward compatibility
+ * WARNING: This will return config based on current mode
+ */
+export const SAFE_ZONE_CONFIG = new Proxy({}, {
+  get(target, prop) {
+    return getSafeZoneConfig()[prop];
+  }
+});
+
+// ════════════════════════════════════════════════════════════════════════════
+// Smart Layout Configuration (การจัดเรียงเนื้อหาอัตโนมัติ)
+// ════════════════════════════════════════════════════════════════════════════
+
+export const SMART_LAYOUT_CONFIG = {
+  fillRatio: 0.92,              // ใช้ 92% ของพื้นที่ใช้งาน
+  stageFallback: {              // ขนาดหน้าจอสำรอง
+    width: 1280,
+    height: 720
+  },
+  autoScale: true,              // ปรับขนาดเนื้อหาอัตโนมัติ
+  maintainAspectRatio: true,    // รักษาสัดส่วน
+  centerContent: true           // จัดกึ่งกลาง
+};
+
+/**
+ * Get Smart Layout fill ratio
+ */
+export function getSmartLayoutFillRatio() {
+  return SMART_LAYOUT_CONFIG.fillRatio;
+}
+
+/**
+ * Get Smart Layout stage fallback dimensions
+ */
+export function getSmartLayoutStageFallback() {
+  return { ...SMART_LAYOUT_CONFIG.stageFallback };
+}
+
+/**
+ * Update Smart Layout configuration
+ */
+export function updateSmartLayoutConfig(newConfig) {
+  Object.assign(SMART_LAYOUT_CONFIG, newConfig);
+  
+  window.dispatchEvent(new CustomEvent('smartLayoutConfigUpdated', {
+    detail: SMART_LAYOUT_CONFIG
+  }));
+  
+  return SMART_LAYOUT_CONFIG;
+}
+
+/**
+ * Get current Smart Layout configuration
+ */
+export function getSmartLayoutConfig() {
+  return { ...SMART_LAYOUT_CONFIG };
+}
+
+/**
+ * Get Safe Zone margins (คำนวณ margins ตามขนาดหน้าจอและโหมดปัจจุบัน)
+ * @param {Object} stageRect - ขนาดและตำแหน่งของ stage
+ * @returns {Object} - { left, right, top, bottom }
+ */
+export function computeSafeZoneMargins(stageRect = {}) {
+  const width = stageRect.width || window.innerWidth;
+  const height = stageRect.height || window.innerHeight;
+  
+  // ใช้ config ตามโหมดปัจจุบัน
+  const safeZoneConfig = getSafeZoneConfig();
+  const config = safeZoneConfig.margins;
+  
+  // คำนวณตามสัดส่วน
+  const horizontalBase = width * config.horizontalRatio;
+  const verticalBase = height * config.verticalRatio;
+  
+  // จำกัดค่าให้อยู่ในช่วงที่กำหนด
+  const left = Math.max(
+    config.minHorizontal,
+    Math.min(horizontalBase, width * config.maxHorizontalRatio)
+  );
+  const right = left;
+  const top = Math.max(
+    config.minVertical,
+    Math.min(verticalBase, height * config.maxVerticalRatio)
+  );
+  const bottom = top;
+  
+  console.log(`[PresentationConfig] Safe Zone margins for ${currentDisplayMode} mode:`, {
+    width, height, left, right, top, bottom
+  });
+  
+  return { left, right, top, bottom };
+}
+
+/**
+ * Update Safe Zone configuration
+ * @param {Object} newConfig - ค่าการตั้งค่าใหม่
+ */
+export function updateSafeZoneConfig(newConfig) {
+  if (newConfig.margins) {
+    Object.assign(SAFE_ZONE_CONFIG.margins, newConfig.margins);
+  }
+  if (newConfig.border) {
+    Object.assign(SAFE_ZONE_CONFIG.border, newConfig.border);
+  }
+  if (newConfig.enforcement) {
+    Object.assign(SAFE_ZONE_CONFIG.enforcement, newConfig.enforcement);
+  }
+  
+  // Dispatch event เพื่อแจ้ง components อื่นๆ
+  window.dispatchEvent(new CustomEvent('safeZoneConfigUpdated', {
+    detail: SAFE_ZONE_CONFIG
+  }));
+  
+  return SAFE_ZONE_CONFIG;
+}
+
+/**
+ * Reset Safe Zone configuration to defaults for all modes
+ */
+export function resetSafeZoneConfig() {
+  // Reset Intro Mode
+  INTRO_SAFE_ZONE_CONFIG.margins = {
+    horizontalRatio: 0.08,
+    verticalRatio: 0.10,
+    maxHorizontalRatio: 0.15,
+    maxVerticalRatio: 0.18,
+    minHorizontal: 60,
+    minVertical: 60
+  };
+  INTRO_SAFE_ZONE_CONFIG.border = {
+    enabled: false,
+    color: 'rgba(100, 116, 139, 0.3)',
+    width: 1,
+    glowColor: 'rgba(100, 116, 139, 0.2)',
+    glowSize: '2px',
+    zIndex: 1000
+  };
+  INTRO_SAFE_ZONE_CONFIG.enforcement = {
+    enabled: false,
+    snapToEdge: false,
+    showWarning: false
+  };
+
+  // Reset Editor Mode
+  EDITOR_SAFE_ZONE_CONFIG.margins = {
+    horizontalRatio: 0.06,
+    verticalRatio: 0.08,
+    maxHorizontalRatio: 0.12,
+    maxVerticalRatio: 0.15,
+    minHorizontal: 40,
+    minVertical: 40
+  };
+  EDITOR_SAFE_ZONE_CONFIG.border = {
+    enabled: true,
+    color: 'rgba(239, 68, 68, 0.8)',
+    width: 2,
+    glowColor: 'rgba(239, 68, 68, 0.5)',
+    glowSize: '6px',
+    zIndex: 9999
+  };
+  EDITOR_SAFE_ZONE_CONFIG.enforcement = {
+    enabled: true,
+    snapToEdge: true,
+    showWarning: true
+  };
+
+  // Reset Presentation Mode
+  PRESENTATION_SAFE_ZONE_CONFIG.margins = {
+    horizontalRatio: 0.05,
+    verticalRatio: 0.07,
+    maxHorizontalRatio: 0.10,
+    maxVerticalRatio: 0.12,
+    minHorizontal: 30,
+    minVertical: 30
+  };
+  PRESENTATION_SAFE_ZONE_CONFIG.border = {
+    enabled: false,
+    color: 'rgba(100, 116, 139, 0.2)',
+    width: 1,
+    glowColor: 'rgba(100, 116, 139, 0.1)',
+    glowSize: '2px',
+    zIndex: 100
+  };
+  PRESENTATION_SAFE_ZONE_CONFIG.enforcement = {
+    enabled: false,
+    snapToEdge: false,
+    showWarning: false
+  };
+  
+  window.dispatchEvent(new CustomEvent('safeZoneConfigUpdated', {
+    detail: getSafeZoneConfig()
+  }));
+  
+  return getSafeZoneConfig();
+}
+
+// ════════════════════════════════════════════════════════════════════════════
+// Configuration Presets (Default Configuration Examples)
+// ════════════════════════════════════════════════════════════════════════════
+
+export const CONFIG_PRESETS = {
+  default: {
+    name: 'Default',
+    description: 'Standard default settings',
+    config: {
+      fonts: {
+        heading: "'Inter', 'Segoe UI', sans-serif",
+        body: "'Inter', 'Segoe UI', sans-serif",
+        code: "'Source Code Pro', 'Consolas', monospace"
+      },
+      fontSizes: {
+        h1: { min: 1.75, base: 4.5, max: 3 },      // clamp(1.75rem, 4.5vw, 3rem)
+        h2: { min: 1.5, base: 3.5, max: 2.5 },
+        h3: { min: 1.25, base: 2.8, max: 1.9 },
+        text: { min: 1.1, base: 1.8, max: 1.6 },
+        code: { min: 0.95, base: 1.5, max: 1.3 }
+      },
+      colors: {
+        primary: '#60a5fa',
+        secondary: '#a855f7',
+        background: '#0a1628',
+        surface: '#132337',
+        text: '#e2e8f0',
+        textSecondary: '#94a3b8',
+        accent: '#06b6d4',
+        codeBackground: '#1e293b',
+        codeBorder: '#334155'
+      },
+      background: {
+        type: 'solid',           // 'solid', 'gradient', 'image'
+        value: '#0a1628',
+        gradient: null,
+        image: null,
+        opacity: 1
+      },
+      animations: {
+        enabled: true,
+        duration: 0.6,
+        easing: 'cubic-bezier(0.4, 0, 0.2, 1)',
+        slideTransition: 'fade',  // 'fade', 'slide', 'none'
+      },
+      styles: {
+        borderRadius: '1.25rem',
+        shadow: '0 20px 40px rgba(0, 0, 0, 0.3)',
+        lineHeight: {
+          heading: 1.3,
+          body: 1.7
+        },
+        // UI Elements
+        previewOpacity: 0.68,
+        overlayBackground: 'rgba(10, 22, 40, 0.85)',
+        overlayBlur: '8px',
+        navBorderWidth: '2px',
+        navBorderOpacity: 0.5,
+        // Borders & Accents
+        headingAccentBorderWidth: '4px',
+        blockquoteBorderWidth: '4px',
+        imageBorderWidth: '2px',
+        linkUnderlineWidth: '2px',
+        tableBorderWidth: '1px',
+        hrBorderWidth: '2px',
+        // Effects
+        backdropGradientColor: 'rgba(59, 130, 246, 0.15)',
+        backdropGradientSpread: '70%',
+        backdropBlur: '60px',
+        // Page Indicator
+        pageIndicatorTop: '16px',
+        pageIndicatorRight: '16px',
+        pageIndicatorFontSize: '0.875rem',  // text-sm
+        pageIndicatorOpacity: 0.7,
+        pageIndicatorPaddingX: '12px',      // px-3
+        pageIndicatorPaddingY: '4px',       // py-1
+        pageIndicatorBgColor: 'rgba(22, 78, 99, 0.5)',  // bg-cyan-900/50
+        pageIndicatorTextColor: '#a5f3fc'   // text-cyan-200
+      },
+      typography: {
+        paragraphSpacing: {
+          before: 0.5,    // rem
+          after: 1        // rem
+        },
+        headingSpacing: {
+          before: 1.5,    // rem
+          after: 0.75     // rem
+        },
+        indentation: {
+          firstLine: 0,   // rem
+          hanging: 0,     // rem
+          blockQuote: 1.5 // rem
+        },
+        listIndent: 1.5,  // rem
+        textAlign: 'left' // 'left', 'center', 'right', 'justify'
+      },
+      layout: {
+        contentPadding: {
+          small: 40,      // px - for small screens
+          large: 48,      // px - for large screens
+          ultra: 64       // px - for ultra-wide screens
+        },
+        contentAlignment: {
+          horizontal: 'center',  // 'flex-start', 'center', 'flex-end'
+          vertical: 'center'     // 'flex-start', 'center', 'flex-end'
+        }
+      },
+      smartList: {
+        twoColumnThreshold: 6,   // items threshold for 2-column layout
+        threeColumnThreshold: 12 // items threshold for 3-column layout
+      }
+    }
+  },
+
+  professional: {
+    name: 'Professional',
+    description: 'For business presentations',
+    config: {
+      fonts: {
+        heading: "'Montserrat', 'Arial', sans-serif",
+        body: "'Lato', 'Helvetica', sans-serif",
+        code: "'Fira Code', monospace"
+      },
+      fontSizes: {
+        h1: { min: 2, base: 5, max: 3.5 },
+        h2: { min: 1.6, base: 4, max: 2.8 },
+        h3: { min: 1.3, base: 3, max: 2.1 },
+        text: { min: 1.2, base: 2, max: 1.8 },
+        code: { min: 1, base: 1.6, max: 1.4 }
+      },
+      colors: {
+        primary: '#3b82f6',
+        secondary: '#8b5cf6',
+        background: '#0f172a',
+        surface: '#1e293b',
+        text: '#f1f5f9',
+        textSecondary: '#cbd5e1',
+        accent: '#0ea5e9',
+        codeBackground: '#1e293b',
+        codeBorder: '#475569'
+      },
+      background: {
+        type: 'gradient',
+        value: null,
+        gradient: 'linear-gradient(135deg, #0f172a 0%, #1e293b 100%)',
+        image: null,
+        opacity: 1
+      },
+      animations: {
+        enabled: true,
+        duration: 0.7,
+        easing: 'cubic-bezier(0.25, 0.1, 0.25, 1)',
+        slideTransition: 'slide'
+      },
+      styles: {
+        borderRadius: '0.75rem',
+        shadow: '0 25px 50px rgba(0, 0, 0, 0.5)',
+        lineHeight: {
+          heading: 1.4,
+          body: 1.8
+        },
+        // UI Elements
+        previewOpacity: 0.68,
+        overlayBackground: 'rgba(15, 23, 42, 0.9)',
+        overlayBlur: '10px',
+        navBorderWidth: '2px',
+        navBorderOpacity: 0.6,
+        // Borders & Accents
+        headingAccentBorderWidth: '4px',
+        blockquoteBorderWidth: '4px',
+        imageBorderWidth: '2px',
+        linkUnderlineWidth: '2px',
+        tableBorderWidth: '1px',
+        hrBorderWidth: '2px',
+        // Effects
+        backdropGradientColor: 'rgba(59, 130, 246, 0.2)',
+        backdropGradientSpread: '65%',
+        backdropBlur: '80px',
+        // Page Indicator
+        pageIndicatorTop: '16px',
+        pageIndicatorRight: '16px',
+        pageIndicatorFontSize: '0.875rem',
+        pageIndicatorOpacity: 0.7,
+        pageIndicatorPaddingX: '12px',
+        pageIndicatorPaddingY: '4px',
+        pageIndicatorBgColor: 'rgba(30, 41, 59, 0.6)',
+        pageIndicatorTextColor: '#cbd5e1'
+      },
+      typography: {
+        paragraphSpacing: {
+          before: 0.75,
+          after: 1.25
+        },
+        headingSpacing: {
+          before: 2,
+          after: 1
+        },
+        indentation: {
+          firstLine: 0,
+          hanging: 0,
+          blockQuote: 2
+        },
+        listIndent: 2,
+        textAlign: 'left'
+      },
+      layout: {
+        contentPadding: {
+          small: 48,
+          large: 56,
+          ultra: 72
+        },
+        contentAlignment: {
+          horizontal: 'flex-start',
+          vertical: 'flex-start'
+        }
+      },
+      smartList: {
+        twoColumnThreshold: 6,
+        threeColumnThreshold: 12
+      }
+    }
+  },
+
+  minimal: {
+    name: 'Minimal',
+    description: 'Simple and clear design',
+    config: {
+      fonts: {
+        heading: "'Helvetica Neue', 'Arial', sans-serif",
+        body: "'Helvetica Neue', 'Arial', sans-serif",
+        code: "'SF Mono', 'Monaco', monospace"
+      },
+      fontSizes: {
+        h1: { min: 1.5, base: 4, max: 2.5 },
+        h2: { min: 1.3, base: 3, max: 2 },
+        h3: { min: 1.15, base: 2.5, max: 1.7 },
+        text: { min: 1, base: 1.6, max: 1.4 },
+        code: { min: 0.9, base: 1.4, max: 1.2 }
+      },
+      colors: {
+        primary: '#000000',
+        secondary: '#333333',
+        background: '#ffffff',
+        surface: '#f8f9fa',
+        text: '#000000',
+        textSecondary: '#666666',
+        accent: '#0066cc',
+        codeBackground: '#f5f5f5',
+        codeBorder: '#e0e0e0'
+      },
+      background: {
+        type: 'solid',
+        value: '#ffffff',
+        gradient: null,
+        image: null,
+        opacity: 1
+      },
+      animations: {
+        enabled: true,
+        duration: 0.3,
+        easing: 'ease-out',
+        slideTransition: 'fade'
+      },
+      styles: {
+        borderRadius: '0',
+        shadow: 'none',
+        lineHeight: {
+          heading: 1.2,
+          body: 1.6
+        },
+        // UI Elements
+        previewOpacity: 0.68,
+        overlayBackground: 'rgba(255, 255, 255, 0.85)',
+        overlayBlur: '6px',
+        navBorderWidth: '1px',
+        navBorderOpacity: 0.3,
+        // Borders & Accents
+        headingAccentBorderWidth: '2px',
+        blockquoteBorderWidth: '3px',
+        imageBorderWidth: '1px',
+        linkUnderlineWidth: '1px',
+        tableBorderWidth: '1px',
+        hrBorderWidth: '1px',
+        // Effects
+        backdropGradientColor: 'rgba(0, 102, 204, 0.05)',
+        backdropGradientSpread: '50%',
+        backdropBlur: '20px',
+        // Page Indicator
+        pageIndicatorTop: '12px',
+        pageIndicatorRight: '12px',
+        pageIndicatorFontSize: '0.75rem',
+        pageIndicatorOpacity: 0.6,
+        pageIndicatorPaddingX: '8px',
+        pageIndicatorPaddingY: '4px',
+        pageIndicatorBgColor: 'rgba(0, 0, 0, 0.1)',
+        pageIndicatorTextColor: '#666666'
+      },
+      typography: {
+        paragraphSpacing: {
+          before: 0.25,
+          after: 0.75
+        },
+        headingSpacing: {
+          before: 1.25,
+          after: 0.5
+        },
+        indentation: {
+          firstLine: 0,
+          hanging: 0,
+          blockQuote: 1
+        },
+        listIndent: 1.25,
+        textAlign: 'left'
+      },
+      layout: {
+        contentPadding: {
+          small: 32,
+          large: 40,
+          ultra: 52
+        },
+        contentAlignment: {
+          horizontal: 'center',
+          vertical: 'center'
+        }
+      },
+      smartList: {
+        twoColumnThreshold: 6,
+        threeColumnThreshold: 12
+      }
+    }
+  },
+
+  creative: {
+    name: 'Creative',
+    description: 'Creative and distinctive style',
+    config: {
+      fonts: {
+        heading: "'Poppins', 'Verdana', sans-serif",
+        body: "'Inter', sans-serif",
+        code: "'JetBrains Mono', monospace"
+      },
+      fontSizes: {
+        h1: { min: 2.2, base: 5.5, max: 4 },
+        h2: { min: 1.8, base: 4.5, max: 3 },
+        h3: { min: 1.4, base: 3.5, max: 2.3 },
+        text: { min: 1.15, base: 2, max: 1.7 },
+        code: { min: 1, base: 1.7, max: 1.5 }
+      },
+      colors: {
+        primary: '#ec4899',
+        secondary: '#8b5cf6',
+        background: '#1a0b2e',
+        surface: '#2d1b4e',
+        text: '#f0e7ff',
+        textSecondary: '#c4b5fd',
+        accent: '#f59e0b',
+        codeBackground: '#2d1b4e',
+        codeBorder: '#4c3575'
+      },
+      background: {
+        type: 'gradient',
+        value: null,
+        gradient: 'linear-gradient(135deg, #1a0b2e 0%, #2d1b4e 50%, #4c1d95 100%)',
+        image: null,
+        opacity: 1
+      },
+      animations: {
+        enabled: true,
+        duration: 0.8,
+        easing: 'cubic-bezier(0.68, -0.55, 0.265, 1.55)',
+        slideTransition: 'slide'
+      },
+      styles: {
+        borderRadius: '2rem',
+        shadow: '0 30px 60px rgba(139, 92, 246, 0.4)',
+        lineHeight: {
+          heading: 1.35,
+          body: 1.75
+        },
+        // UI Elements
+        previewOpacity: 0.68,
+        overlayBackground: 'rgba(26, 11, 46, 0.9)',
+        overlayBlur: '12px',
+        navBorderWidth: '3px',
+        navBorderOpacity: 0.7,
+        // Borders & Accents
+        headingAccentBorderWidth: '6px',
+        blockquoteBorderWidth: '5px',
+        imageBorderWidth: '3px',
+        linkUnderlineWidth: '3px',
+        tableBorderWidth: '2px',
+        hrBorderWidth: '4px',
+        // Effects
+        backdropGradientColor: 'rgba(236, 72, 153, 0.25)',
+        backdropGradientSpread: '75%',
+        backdropBlur: '100px',
+        // Page Indicator
+        pageIndicatorTop: '20px',
+        pageIndicatorRight: '20px',
+        pageIndicatorFontSize: '1rem',
+        pageIndicatorOpacity: 0.8,
+        pageIndicatorPaddingX: '16px',
+        pageIndicatorPaddingY: '6px',
+        pageIndicatorBgColor: 'rgba(139, 92, 246, 0.4)',
+        pageIndicatorTextColor: '#f0e7ff'
+      },
+      typography: {
+        paragraphSpacing: {
+          before: 0.5,
+          after: 1.5
+        },
+        headingSpacing: {
+          before: 2,
+          after: 1.25
+        },
+        indentation: {
+          firstLine: 0,
+          hanging: 0,
+          blockQuote: 2
+        },
+        listIndent: 2,
+        textAlign: 'left'
+      },
+      layout: {
+        contentPadding: {
+          small: 40,
+          large: 52,
+          ultra: 68
+        },
+        contentAlignment: {
+          horizontal: 'center',
+          vertical: 'center'
+        }
+      },
+      smartList: {
+        twoColumnThreshold: 6,
+        threeColumnThreshold: 12
+      }
+    }
+  }
+};
+
+// ════════════════════════════════════════════════════════════════════════════
+// Configuration Options (ตัวเลือกที่ใช้ได้)
+// ════════════════════════════════════════════════════════════════════════════
+
+export const FONT_OPTIONS = {
+  heading: [
+    { value: "'Inter', 'Segoe UI', sans-serif", label: 'Inter (Modern)' },
+    { value: "'Montserrat', 'Arial', sans-serif", label: 'Montserrat (Professional)' },
+    { value: "'Poppins', 'Verdana', sans-serif", label: 'Poppins (Friendly)' },
+    { value: "'Playfair Display', 'Georgia', serif", label: 'Playfair Display (Elegant)' },
+    { value: "'Space Grotesk', sans-serif", label: 'Space Grotesk (Tech)' },
+    { value: "'Helvetica Neue', 'Arial', sans-serif", label: 'Helvetica (Clean)' },
+    { value: "'Ubuntu', sans-serif", label: 'Ubuntu (Casual)' },
+    { value: "'Orbitron', sans-serif", label: 'Orbitron (Futuristic)' }
+  ],
+  body: [
+    { value: "'Inter', 'Segoe UI', sans-serif", label: 'Inter' },
+    { value: "'Lato', 'Helvetica', sans-serif", label: 'Lato' },
+    { value: "'Roboto', sans-serif", label: 'Roboto' },
+    { value: "'Open Sans', sans-serif", label: 'Open Sans' },
+    { value: "'Helvetica Neue', 'Arial', sans-serif", label: 'Helvetica' },
+    { value: "'Ubuntu', sans-serif", label: 'Ubuntu' }
+  ],
+  code: [
+    { value: "'Source Code Pro', 'Consolas', monospace", label: 'Source Code Pro' },
+    { value: "'Fira Code', monospace", label: 'Fira Code' },
+    { value: "'JetBrains Mono', monospace", label: 'JetBrains Mono' },
+    { value: "'Roboto Mono', monospace", label: 'Roboto Mono' },
+    { value: "'SF Mono', 'Monaco', monospace", label: 'SF Mono' },
+    { value: "'Courier Prime', 'Courier New', monospace", label: 'Courier' }
+  ]
+};
+
+export const BACKGROUND_TYPES = [
+  { value: 'solid', label: 'สีพื้น' },
+  { value: 'gradient', label: 'ไล่สี' },
+  { value: 'image', label: 'รูปภาพ' }
+];
+
+export const TRANSITION_TYPES = [
+  { value: 'fade', label: 'Fade (จางเข้า-จางออก)' },
+  { value: 'slide', label: 'Slide (เลื่อน)' },
+  { value: 'none', label: 'ไม่มีเอฟเฟค' }
+];
+
+export const TEXT_ALIGN_OPTIONS = [
+  { value: 'left', label: 'ชิดซ้าย' },
+  { value: 'center', label: 'กึ่งกลาง' },
+  { value: 'right', label: 'ชิดขวา' },
+  { value: 'justify', label: 'เต็มแนว' }
+];
+
+// ════════════════════════════════════════════════════════════════════════════
+// Configuration Management
+// ════════════════════════════════════════════════════════════════════════════
+
+let currentConfig = { ...CONFIG_PRESETS.default.config };
+
+/**
+ * ดึงค่า configuration ปัจจุบัน
+ */
+export function getCurrentConfig() {
+  return { ...currentConfig };
+}
+
+/**
+ * ตั้งค่า configuration ใหม่
+ */
+export function setConfig(newConfig, autoSave = true) {
+  currentConfig = { ...currentConfig, ...newConfig };
+  applyConfigToDOM();
+  
+  // Auto-save to localStorage
+  if (autoSave) {
+    ConfigStorage.autoSave(currentConfig);
+  }
+  
+  return currentConfig;
+}
+
+/**
+ * อัปเดตค่าเฉพาะส่วน (รองรับ nested objects)
+ */
+export function updateConfigPart(part, values, autoSave = true) {
+  if (!currentConfig[part]) {
+    currentConfig[part] = values;
+  } else if (typeof values === 'object' && !Array.isArray(values)) {
+    // Deep merge for nested objects
+    currentConfig[part] = deepMerge(currentConfig[part], values);
+  } else {
+    currentConfig[part] = values;
+  }
+  applyConfigToDOM();
+  
+  // Auto-save to localStorage
+  if (autoSave) {
+    ConfigStorage.autoSave(currentConfig);
+  }
+  
+  return currentConfig;
+}
+
+/**
+ * Deep merge helper function
+ */
+function deepMerge(target, source) {
+  const result = { ...target };
+  
+  for (const key in source) {
+    if (source.hasOwnProperty(key)) {
+      if (source[key] && typeof source[key] === 'object' && !Array.isArray(source[key])) {
+        result[key] = deepMerge(result[key] || {}, source[key]);
+      } else {
+        result[key] = source[key];
+      }
+    }
+  }
+  
+  return result;
+}
+
+/**
+ * โหลด preset
+ */
+export function loadPreset(presetName, autoSave = true) {
+  const preset = CONFIG_PRESETS[presetName];
+  if (!preset) {
+    console.error(`Preset "${presetName}" not found`);
+    return null;
+  }
+  currentConfig = { ...preset.config };
+  applyConfigToDOM();
+  
+  // Auto-save to localStorage
+  if (autoSave) {
+    ConfigStorage.autoSave(currentConfig);
+  }
+  
+  return currentConfig;
+}
+
+/**
+ * รีเซ็ตเป็นค่าเริ่มต้น
+ */
+export function resetConfig(autoSave = true) {
+  currentConfig = { ...CONFIG_PRESETS.default.config };
+  applyConfigToDOM();
+  
+  // Clear saved config และ save default
+  if (autoSave) {
+    ConfigStorage.clearLocalStorage();
+    ConfigStorage.saveToLocalStorage(currentConfig);
+  }
+  
+  return currentConfig;
+}
+
+/**
+ * โหลดการตั้งค่าที่บันทึกไว้จาก localStorage
+ */
+export function loadSavedConfig() {
+  const savedConfig = ConfigStorage.loadFromLocalStorage();
+  if (savedConfig) {
+    currentConfig = { ...CONFIG_PRESETS.default.config, ...savedConfig };
+    applyConfigToDOM();
+    console.log('[PresentationConfig] ✅ Loaded saved config from localStorage');
+    return currentConfig;
+  }
+  console.log('[PresentationConfig] No saved config found, using default');
+  return null;
+}
+
+/**
+ * Export การตั้งค่าปัจจุบันเป็นไฟล์
+ */
+export async function exportConfigToFile() {
+  return ConfigStorage.exportToFile(currentConfig);
+}
+
+/**
+ * Import การตั้งค่าจากไฟล์
+ */
+export async function importConfigFromFile() {
+  try {
+    const importedConfig = await ConfigStorage.importFromFile();
+    if (importedConfig) {
+      currentConfig = { ...CONFIG_PRESETS.default.config, ...importedConfig };
+      applyConfigToDOM();
+      ConfigStorage.saveToLocalStorage(currentConfig);
+      console.log('[PresentationConfig] ✅ Imported config from file');
+      return currentConfig;
+    }
+  } catch (error) {
+    console.error('[PresentationConfig] Failed to import config:', error);
+  }
+  return null;
+}
+
+/**
+ * ดึงรายชื่อ presets ทั้งหมด
+ */
+export function getAllPresets() {
+  return Object.entries(CONFIG_PRESETS).map(([key, preset]) => ({
+    id: key,
+    name: preset.name,
+    description: preset.description
+  }));
+}
+
+/**
+ * แปลง font size config เป็น clamp CSS
+ */
+function generateClampCSS(sizeConfig) {
+  return `clamp(${sizeConfig.min}rem, ${sizeConfig.base}vw, ${sizeConfig.max}rem)`;
+}
+
+/**
+ * ใส่ค่า configuration ลงใน DOM
+ */
+export function applyConfigToDOM() {
+  const root = document.documentElement;
+  
+  console.log('[PresentationConfig] Applying configuration to DOM...', currentConfig);
+
+  // Fonts
+  root.style.setProperty('--font-heading', currentConfig.fonts.heading);
+  root.style.setProperty('--font-body', currentConfig.fonts.body);
+  root.style.setProperty('--font-code', currentConfig.fonts.code);
+  root.style.setProperty('--font-primary', currentConfig.fonts.body); // Backward compatibility
+
+  // Font Sizes
+  const h1Size = generateClampCSS(currentConfig.fontSizes.h1);
+  const h2Size = generateClampCSS(currentConfig.fontSizes.h2);
+  const h3Size = generateClampCSS(currentConfig.fontSizes.h3);
+  const textSize = generateClampCSS(currentConfig.fontSizes.text);
+  const codeSize = generateClampCSS(currentConfig.fontSizes.code);
+  
+  root.style.setProperty('--font-size-h1', h1Size);
+  root.style.setProperty('--font-size-h2', h2Size);
+  root.style.setProperty('--font-size-h3', h3Size);
+  root.style.setProperty('--font-size-text', textSize);
+  root.style.setProperty('--font-size-code', codeSize);
+  
+  console.log('[PresentationConfig] Font sizes applied:', {
+    h1: h1Size,
+    h2: h2Size,
+    h3: h3Size,
+    text: textSize,
+    code: codeSize
+  });
+
+  // Colors
+  root.style.setProperty('--color-primary', currentConfig.colors.primary);
+  root.style.setProperty('--color-secondary', currentConfig.colors.secondary);
+  root.style.setProperty('--color-background', currentConfig.colors.background);
+  root.style.setProperty('--color-surface', currentConfig.colors.surface);
+  root.style.setProperty('--color-text', currentConfig.colors.text);
+  root.style.setProperty('--color-text-secondary', currentConfig.colors.textSecondary);
+  root.style.setProperty('--color-accent', currentConfig.colors.accent);
+  root.style.setProperty('--color-code-bg', currentConfig.colors.codeBackground);
+  root.style.setProperty('--color-code-border', currentConfig.colors.codeBorder);
+  
+  console.log('[PresentationConfig] Colors applied:', currentConfig.colors);
+
+  // Background
+  if (currentConfig.background.type === 'solid') {
+    document.body.style.background = currentConfig.background.value;
+  } else if (currentConfig.background.type === 'gradient') {
+    document.body.style.background = currentConfig.background.gradient;
+  } else if (currentConfig.background.type === 'image' && currentConfig.background.image) {
+    document.body.style.background = `url(${currentConfig.background.image})`;
+    document.body.style.backgroundSize = 'cover';
+    document.body.style.backgroundPosition = 'center';
+  }
+
+  // Animations
+  root.style.setProperty('--anim-duration', `${currentConfig.animations.duration}s`);
+  root.style.setProperty('--anim-easing', currentConfig.animations.easing);
+
+  // Styles
+  root.style.setProperty('--border-radius', currentConfig.styles.borderRadius);
+  root.style.setProperty('--shadow', currentConfig.styles.shadow);
+  root.style.setProperty('--line-height-heading', currentConfig.styles.lineHeight.heading);
+  root.style.setProperty('--line-height-body', currentConfig.styles.lineHeight.body);
+  
+  console.log('[PresentationConfig] Line heights applied:', currentConfig.styles.lineHeight);
+  
+  // UI Elements Styles
+  root.style.setProperty('--preview-opacity', currentConfig.styles.previewOpacity);
+  root.style.setProperty('--overlay-background', currentConfig.styles.overlayBackground);
+  root.style.setProperty('--overlay-blur', currentConfig.styles.overlayBlur);
+  root.style.setProperty('--nav-border-width', currentConfig.styles.navBorderWidth);
+  root.style.setProperty('--nav-border-opacity', currentConfig.styles.navBorderOpacity);
+  
+  // Borders & Accents
+  root.style.setProperty('--heading-accent-border-width', currentConfig.styles.headingAccentBorderWidth);
+  root.style.setProperty('--blockquote-border-width', currentConfig.styles.blockquoteBorderWidth);
+  root.style.setProperty('--image-border-width', currentConfig.styles.imageBorderWidth);
+  root.style.setProperty('--link-underline-width', currentConfig.styles.linkUnderlineWidth);
+  root.style.setProperty('--table-border-width', currentConfig.styles.tableBorderWidth);
+  root.style.setProperty('--hr-border-width', currentConfig.styles.hrBorderWidth);
+  
+  // Effects
+  root.style.setProperty('--backdrop-gradient-color', currentConfig.styles.backdropGradientColor);
+  root.style.setProperty('--backdrop-gradient-spread', currentConfig.styles.backdropGradientSpread);
+  root.style.setProperty('--backdrop-blur', currentConfig.styles.backdropBlur);
+  
+  // Page Indicator
+  root.style.setProperty('--page-indicator-top', currentConfig.styles.pageIndicatorTop);
+  root.style.setProperty('--page-indicator-right', currentConfig.styles.pageIndicatorRight);
+  root.style.setProperty('--page-indicator-font-size', currentConfig.styles.pageIndicatorFontSize);
+  root.style.setProperty('--page-indicator-opacity', currentConfig.styles.pageIndicatorOpacity);
+  root.style.setProperty('--page-indicator-padding-x', currentConfig.styles.pageIndicatorPaddingX);
+  root.style.setProperty('--page-indicator-padding-y', currentConfig.styles.pageIndicatorPaddingY);
+  root.style.setProperty('--page-indicator-bg-color', currentConfig.styles.pageIndicatorBgColor);
+  root.style.setProperty('--page-indicator-text-color', currentConfig.styles.pageIndicatorTextColor);
+
+  // Typography (NEW)
+  if (currentConfig.typography) {
+    console.log('[PresentationConfig] Applying typography:', currentConfig.typography);
+    
+    root.style.setProperty('--paragraph-spacing-before', `${currentConfig.typography.paragraphSpacing.before}rem`);
+    root.style.setProperty('--paragraph-spacing-after', `${currentConfig.typography.paragraphSpacing.after}rem`);
+    root.style.setProperty('--heading-spacing-before', `${currentConfig.typography.headingSpacing.before}rem`);
+    root.style.setProperty('--heading-spacing-after', `${currentConfig.typography.headingSpacing.after}rem`);
+    root.style.setProperty('--indent-first-line', `${currentConfig.typography.indentation.firstLine}rem`);
+    root.style.setProperty('--indent-hanging', `${currentConfig.typography.indentation.hanging || 0}rem`);
+    root.style.setProperty('--indent-blockquote', `${currentConfig.typography.indentation.blockQuote}rem`);
+    root.style.setProperty('--list-indent', `${currentConfig.typography.listIndent}rem`);
+    root.style.setProperty('--text-align', currentConfig.typography.textAlign);
+  }
+  
+  // Layout & Content Positioning (NEW)
+  if (currentConfig.layout) {
+    console.log('[PresentationConfig] Applying layout:', currentConfig.layout);
+    
+    root.style.setProperty('--content-padding-small', `${currentConfig.layout.contentPadding.small}px`);
+    root.style.setProperty('--content-padding-large', `${currentConfig.layout.contentPadding.large}px`);
+    root.style.setProperty('--content-padding-ultra', `${currentConfig.layout.contentPadding.ultra}px`);
+    root.style.setProperty('--content-align-horizontal', currentConfig.layout.contentAlignment.horizontal);
+    root.style.setProperty('--content-align-vertical', currentConfig.layout.contentAlignment.vertical);
+  }
+  
+  // Smart List Columns
+  if (currentConfig.smartList) {
+    root.style.setProperty('--smart-list-two-column-threshold', currentConfig.smartList.twoColumnThreshold);
+    root.style.setProperty('--smart-list-three-column-threshold', currentConfig.smartList.threeColumnThreshold);
+  }
+  
+  console.log('[PresentationConfig] ✅ Configuration applied successfully');
+
+  return currentConfig;
+}
+
+/**
+ * Export configuration เป็น JSON
+ */
+export function exportConfig() {
+  return JSON.stringify(currentConfig, null, 2);
+}
+
+/**
+ * Import configuration จาก JSON
+ */
+export function importConfig(jsonString) {
+  try {
+    const imported = JSON.parse(jsonString);
+    currentConfig = { ...CONFIG_PRESETS.default.config, ...imported };
+    applyConfigToDOM();
+    return currentConfig;
+  } catch (error) {
+    console.error('Failed to import configuration:', error);
+    return null;
+  }
+}
+
+/**
+ * Update typography settings from UI values
+ * @param {Object} values - Typography values from UI
+ */
+export function updateTypography(values) {
+  if (!currentConfig.typography) {
+    // Use default preset values instead of hardcoding
+    currentConfig.typography = { ...CONFIG_PRESETS.default.config.typography };
+  }
+  
+  // Deep merge typography values
+  currentConfig.typography = deepMerge(currentConfig.typography, values);
+  applyConfigToDOM();
+  return currentConfig;
+}
+
+/**
+ * Get current typography settings
+ */
+export function getTypography() {
+  return currentConfig.typography || null;
+}
+
+// ════════════════════════════════════════════════════════════════════════════
+// UI Integration
+// ════════════════════════════════════════════════════════════════════════════
+
+let uiCallbacks = {
+  onUpdate: null,
+  onSave: null,
+  setStatus: null
+};
+
+/**
+ * Initialize Presentation UI with DOM elements and callbacks
+ * @param {Object} domElements - Object containing all DOM element references
+ * @param {Object} callbacks - Callback functions { onUpdate, onSave, setStatus }
+ */
+export function initPresentationUI(domElements, callbacks = {}) {
+  uiCallbacks = { ...uiCallbacks, ...callbacks };
+  
+  // Populate font options
+  if (domElements.fontHeading && FONT_OPTIONS.heading) {
+    domElements.fontHeading.innerHTML = '';
+    FONT_OPTIONS.heading.forEach(opt => {
+      const option = document.createElement('option');
+      option.value = opt.value;
+      option.textContent = opt.label;
+      domElements.fontHeading.appendChild(option);
+    });
+  }
+
+  if (domElements.fontBody && FONT_OPTIONS.body) {
+    domElements.fontBody.innerHTML = '';
+    FONT_OPTIONS.body.forEach(opt => {
+      const option = document.createElement('option');
+      option.value = opt.value;
+      option.textContent = opt.label;
+      domElements.fontBody.appendChild(option);
+    });
+  }
+
+  if (domElements.fontCode && FONT_OPTIONS.code) {
+    domElements.fontCode.innerHTML = '';
+    FONT_OPTIONS.code.forEach(opt => {
+      const option = document.createElement('option');
+      option.value = opt.value;
+      option.textContent = opt.label;
+      domElements.fontCode.appendChild(option);
+    });
+  }
+
+  // Load current config into UI
+  loadConfigToUI(domElements);
+
+  // Setup event listeners
+  setupPresetListener(domElements);
+  setupFontListeners(domElements);
+  setupColorListeners(domElements);
+  setupAnimationListeners(domElements);
+  setupFontSizeListeners(domElements);
+  setupUIStylesListeners(domElements);
+  setupTypographyListeners(domElements);
+  setupLayoutListeners(domElements);
+  setupActionButtons(domElements);
+}
+
+/**
+ * Load current configuration to UI inputs
+ */
+function loadConfigToUI(domElements) {
+  // Load fonts
+  if (domElements.fontHeading) domElements.fontHeading.value = currentConfig.fonts.heading;
+  if (domElements.fontBody) domElements.fontBody.value = currentConfig.fonts.body;
+  if (domElements.fontCode) domElements.fontCode.value = currentConfig.fonts.code;
+
+  // Load colors
+  if (domElements.colorPrimary) domElements.colorPrimary.value = currentConfig.colors.primary;
+  if (domElements.colorAccent) domElements.colorAccent.value = currentConfig.colors.accent;
+  if (domElements.colorBackground) domElements.colorBackground.value = currentConfig.colors.background;
+  if (domElements.colorText) domElements.colorText.value = currentConfig.colors.text;
+
+  // Load animations
+  if (domElements.animationTransition) domElements.animationTransition.value = currentConfig.animations.slideTransition;
+  if (domElements.animationDuration) domElements.animationDuration.value = currentConfig.animations.duration;
+
+  // Load font sizes
+  if (currentConfig.fontSizes) {
+    if (domElements.fontSizeH1Min) domElements.fontSizeH1Min.value = currentConfig.fontSizes.h1.min;
+    if (domElements.fontSizeH1Base) domElements.fontSizeH1Base.value = currentConfig.fontSizes.h1.base;
+    if (domElements.fontSizeH1Max) domElements.fontSizeH1Max.value = currentConfig.fontSizes.h1.max;
+    if (domElements.fontSizeH2Min) domElements.fontSizeH2Min.value = currentConfig.fontSizes.h2.min;
+    if (domElements.fontSizeH2Base) domElements.fontSizeH2Base.value = currentConfig.fontSizes.h2.base;
+    if (domElements.fontSizeH2Max) domElements.fontSizeH2Max.value = currentConfig.fontSizes.h2.max;
+    if (domElements.fontSizeTextMin) domElements.fontSizeTextMin.value = currentConfig.fontSizes.text.min;
+    if (domElements.fontSizeTextBase) domElements.fontSizeTextBase.value = currentConfig.fontSizes.text.base;
+    if (domElements.fontSizeTextMax) domElements.fontSizeTextMax.value = currentConfig.fontSizes.text.max;
+  }
+
+  // Load line height
+  if (currentConfig.styles && currentConfig.styles.lineHeight) {
+    if (domElements.lineHeightHeading) domElements.lineHeightHeading.value = currentConfig.styles.lineHeight.heading;
+    if (domElements.lineHeightBody) domElements.lineHeightBody.value = currentConfig.styles.lineHeight.body;
+  }
+
+  // Load UI & Visual Effects
+  if (currentConfig.styles) {
+    if (domElements.previewOpacity) domElements.previewOpacity.value = currentConfig.styles.previewOpacity;
+    if (domElements.overlayBlur) domElements.overlayBlur.value = parseInt(currentConfig.styles.overlayBlur);
+    if (domElements.navBorderWidth) domElements.navBorderWidth.value = parseInt(currentConfig.styles.navBorderWidth);
+    if (domElements.backdropSpread) domElements.backdropSpread.value = parseInt(currentConfig.styles.backdropGradientSpread);
+    if (domElements.backdropBlur) domElements.backdropBlur.value = parseInt(currentConfig.styles.backdropBlur);
+  }
+
+  // Load Border Widths
+  if (currentConfig.styles) {
+    if (domElements.headingBorderWidth) domElements.headingBorderWidth.value = parseInt(currentConfig.styles.headingAccentBorderWidth);
+    if (domElements.blockquoteBorderWidth) domElements.blockquoteBorderWidth.value = parseInt(currentConfig.styles.blockquoteBorderWidth);
+    if (domElements.imageBorderWidth) domElements.imageBorderWidth.value = parseInt(currentConfig.styles.imageBorderWidth);
+    if (domElements.linkUnderlineWidth) domElements.linkUnderlineWidth.value = parseInt(currentConfig.styles.linkUnderlineWidth);
+    if (domElements.tableBorderWidth) domElements.tableBorderWidth.value = parseInt(currentConfig.styles.tableBorderWidth);
+    if (domElements.hrBorderWidth) domElements.hrBorderWidth.value = parseInt(currentConfig.styles.hrBorderWidth);
+  }
+
+  // Load typography
+  if (currentConfig.typography) {
+    if (domElements.paragraphBefore) domElements.paragraphBefore.value = currentConfig.typography.paragraphSpacing.before;
+    if (domElements.paragraphAfter) domElements.paragraphAfter.value = currentConfig.typography.paragraphSpacing.after;
+    if (domElements.headingBefore) domElements.headingBefore.value = currentConfig.typography.headingSpacing.before;
+    if (domElements.headingAfter) domElements.headingAfter.value = currentConfig.typography.headingSpacing.after;
+    if (domElements.indentFirst) domElements.indentFirst.value = currentConfig.typography.indentation.firstLine;
+    if (domElements.indentBlockquote) domElements.indentBlockquote.value = currentConfig.typography.indentation.blockQuote;
+    if (domElements.listIndent) domElements.listIndent.value = currentConfig.typography.listIndent;
+    if (domElements.textAlign) domElements.textAlign.value = currentConfig.typography.textAlign;
+  }
+
+  // Load Page Indicator
+  if (currentConfig.styles) {
+    if (domElements.pageIndicatorTop) domElements.pageIndicatorTop.value = parseInt(currentConfig.styles.pageIndicatorTop);
+    if (domElements.pageIndicatorRight) domElements.pageIndicatorRight.value = parseInt(currentConfig.styles.pageIndicatorRight);
+    if (domElements.pageIndicatorFontSize) domElements.pageIndicatorFontSize.value = parseFloat(currentConfig.styles.pageIndicatorFontSize);
+    if (domElements.pageIndicatorOpacity) domElements.pageIndicatorOpacity.value = currentConfig.styles.pageIndicatorOpacity;
+    if (domElements.pageIndicatorPaddingX) domElements.pageIndicatorPaddingX.value = parseInt(currentConfig.styles.pageIndicatorPaddingX);
+    if (domElements.pageIndicatorPaddingY) domElements.pageIndicatorPaddingY.value = parseInt(currentConfig.styles.pageIndicatorPaddingY);
+    if (domElements.pageIndicatorBgColor) domElements.pageIndicatorBgColor.value = currentConfig.styles.pageIndicatorBgColor;
+    if (domElements.pageIndicatorTextColor) domElements.pageIndicatorTextColor.value = currentConfig.styles.pageIndicatorTextColor;
+  }
+
+  // Load Smart List Column Settings
+  if (currentConfig.smartList) {
+    if (domElements.smartListTwoColumn) domElements.smartListTwoColumn.value = currentConfig.smartList.twoColumnThreshold;
+    if (domElements.smartListThreeColumn) domElements.smartListThreeColumn.value = currentConfig.smartList.threeColumnThreshold;
+  }
+
+  // Load Content Layout & Positioning Settings
+  if (currentConfig.layout) {
+    if (domElements.contentPaddingSmall) domElements.contentPaddingSmall.value = currentConfig.layout.contentPadding.small;
+    if (domElements.contentPaddingLarge) domElements.contentPaddingLarge.value = currentConfig.layout.contentPadding.large;
+    if (domElements.contentPaddingUltra) domElements.contentPaddingUltra.value = currentConfig.layout.contentPadding.ultra;
+    if (domElements.contentAlignHorizontal) domElements.contentAlignHorizontal.value = currentConfig.layout.contentAlignment.horizontal;
+    if (domElements.contentAlignVertical) domElements.contentAlignVertical.value = currentConfig.layout.contentAlignment.vertical;
+  }
+}
+
+/**
+ * Reload UI from current configuration (exported for external use)
+ */
+export function reloadUI(domElements) {
+  loadConfigToUI(domElements);
+}
+
+/**
+ * Load configuration from frontmatter object
+ * @param {Object} frontmatter - Frontmatter key-value pairs
+ * @param {Object} domElements - DOM element references for updating UI
+ */
+export function loadConfigFromFrontmatter(frontmatter, domElements) {
+  // Load preset first if specified
+  if (frontmatter['presentation.preset']) {
+    const presetName = frontmatter['presentation.preset'];
+    loadPreset(presetName);
+    if (domElements && domElements.presetSelector) {
+      domElements.presetSelector.value = presetName;
+    }
+  }
+
+  // Load fonts (overrides preset if specified)
+  const fontUpdates = {};
+  if (frontmatter['presentation.fonts.heading']) {
+    fontUpdates.heading = frontmatter['presentation.fonts.heading'];
+  }
+  if (frontmatter['presentation.fonts.body']) {
+    fontUpdates.body = frontmatter['presentation.fonts.body'];
+  }
+  if (frontmatter['presentation.fonts.code']) {
+    fontUpdates.code = frontmatter['presentation.fonts.code'];
+  }
+  if (Object.keys(fontUpdates).length > 0) {
+    updateConfigPart('fonts', fontUpdates);
+  }
+
+  // Load colors
+  const colorUpdates = {};
+  if (frontmatter['presentation.colors.primary']) {
+    colorUpdates.primary = frontmatter['presentation.colors.primary'];
+  }
+  if (frontmatter['presentation.colors.accent']) {
+    colorUpdates.accent = frontmatter['presentation.colors.accent'];
+  }
+  if (frontmatter['presentation.colors.background']) {
+    colorUpdates.background = frontmatter['presentation.colors.background'];
+  }
+  if (frontmatter['presentation.colors.text']) {
+    colorUpdates.text = frontmatter['presentation.colors.text'];
+  }
+  if (Object.keys(colorUpdates).length > 0) {
+    updateConfigPart('colors', colorUpdates);
+  }
+
+  // Load animations
+  const animationUpdates = {};
+  if (frontmatter['presentation.animations.slideTransition']) {
+    animationUpdates.slideTransition = frontmatter['presentation.animations.slideTransition'];
+  }
+  if (frontmatter['presentation.animations.duration'] !== undefined) {
+    animationUpdates.duration = parseFloat(frontmatter['presentation.animations.duration']);
+  }
+  if (Object.keys(animationUpdates).length > 0) {
+    updateConfigPart('animations', animationUpdates);
+  }
+
+  // Load font sizes
+  const fontSizeUpdates = {};
+  
+  if (frontmatter['presentation.fontSizes.h1.min'] !== undefined) {
+    if (!fontSizeUpdates.h1) fontSizeUpdates.h1 = {};
+    fontSizeUpdates.h1.min = parseFloat(frontmatter['presentation.fontSizes.h1.min']);
+  }
+  if (frontmatter['presentation.fontSizes.h1.base'] !== undefined) {
+    if (!fontSizeUpdates.h1) fontSizeUpdates.h1 = {};
+    fontSizeUpdates.h1.base = parseFloat(frontmatter['presentation.fontSizes.h1.base']);
+  }
+  if (frontmatter['presentation.fontSizes.h1.max'] !== undefined) {
+    if (!fontSizeUpdates.h1) fontSizeUpdates.h1 = {};
+    fontSizeUpdates.h1.max = parseFloat(frontmatter['presentation.fontSizes.h1.max']);
+  }
+  if (frontmatter['presentation.fontSizes.h2.min'] !== undefined) {
+    if (!fontSizeUpdates.h2) fontSizeUpdates.h2 = {};
+    fontSizeUpdates.h2.min = parseFloat(frontmatter['presentation.fontSizes.h2.min']);
+  }
+  if (frontmatter['presentation.fontSizes.h2.base'] !== undefined) {
+    if (!fontSizeUpdates.h2) fontSizeUpdates.h2 = {};
+    fontSizeUpdates.h2.base = parseFloat(frontmatter['presentation.fontSizes.h2.base']);
+  }
+  if (frontmatter['presentation.fontSizes.h2.max'] !== undefined) {
+    if (!fontSizeUpdates.h2) fontSizeUpdates.h2 = {};
+    fontSizeUpdates.h2.max = parseFloat(frontmatter['presentation.fontSizes.h2.max']);
+  }
+  if (frontmatter['presentation.fontSizes.text.min'] !== undefined) {
+    if (!fontSizeUpdates.text) fontSizeUpdates.text = {};
+    fontSizeUpdates.text.min = parseFloat(frontmatter['presentation.fontSizes.text.min']);
+  }
+  if (frontmatter['presentation.fontSizes.text.base'] !== undefined) {
+    if (!fontSizeUpdates.text) fontSizeUpdates.text = {};
+    fontSizeUpdates.text.base = parseFloat(frontmatter['presentation.fontSizes.text.base']);
+  }
+  if (frontmatter['presentation.fontSizes.text.max'] !== undefined) {
+    if (!fontSizeUpdates.text) fontSizeUpdates.text = {};
+    fontSizeUpdates.text.max = parseFloat(frontmatter['presentation.fontSizes.text.max']);
+  }
+  
+  if (Object.keys(fontSizeUpdates).length > 0) {
+    updateConfigPart('fontSizes', fontSizeUpdates);
+  }
+
+  // Load line height and UI styles
+  const styleUpdates = {};
+  if (frontmatter['presentation.styles.lineHeight.heading'] !== undefined || frontmatter['presentation.styles.lineHeight.body'] !== undefined) {
+    styleUpdates.lineHeight = {};
+    if (frontmatter['presentation.styles.lineHeight.heading'] !== undefined) {
+      styleUpdates.lineHeight.heading = parseFloat(frontmatter['presentation.styles.lineHeight.heading']);
+    }
+    if (frontmatter['presentation.styles.lineHeight.body'] !== undefined) {
+      styleUpdates.lineHeight.body = parseFloat(frontmatter['presentation.styles.lineHeight.body']);
+    }
+  }
+  
+  // Load UI & Visual Effects
+  if (frontmatter['presentation.styles.previewOpacity'] !== undefined) {
+    styleUpdates.previewOpacity = parseFloat(frontmatter['presentation.styles.previewOpacity']);
+  }
+  if (frontmatter['presentation.styles.overlayBlur']) {
+    styleUpdates.overlayBlur = frontmatter['presentation.styles.overlayBlur'];
+  }
+  if (frontmatter['presentation.styles.navBorderWidth']) {
+    styleUpdates.navBorderWidth = frontmatter['presentation.styles.navBorderWidth'];
+  }
+  if (frontmatter['presentation.styles.backdropGradientSpread']) {
+    styleUpdates.backdropGradientSpread = frontmatter['presentation.styles.backdropGradientSpread'];
+  }
+  if (frontmatter['presentation.styles.backdropBlur']) {
+    styleUpdates.backdropBlur = frontmatter['presentation.styles.backdropBlur'];
+  }
+  
+  // Load Border Widths
+  if (frontmatter['presentation.styles.headingAccentBorderWidth']) {
+    styleUpdates.headingAccentBorderWidth = frontmatter['presentation.styles.headingAccentBorderWidth'];
+  }
+  if (frontmatter['presentation.styles.blockquoteBorderWidth']) {
+    styleUpdates.blockquoteBorderWidth = frontmatter['presentation.styles.blockquoteBorderWidth'];
+  }
+  if (frontmatter['presentation.styles.imageBorderWidth']) {
+    styleUpdates.imageBorderWidth = frontmatter['presentation.styles.imageBorderWidth'];
+  }
+  if (frontmatter['presentation.styles.linkUnderlineWidth']) {
+    styleUpdates.linkUnderlineWidth = frontmatter['presentation.styles.linkUnderlineWidth'];
+  }
+  if (frontmatter['presentation.styles.tableBorderWidth']) {
+    styleUpdates.tableBorderWidth = frontmatter['presentation.styles.tableBorderWidth'];
+  }
+  if (frontmatter['presentation.styles.hrBorderWidth']) {
+    styleUpdates.hrBorderWidth = frontmatter['presentation.styles.hrBorderWidth'];
+  }
+  
+  // Load Page Indicator
+  if (frontmatter['presentation.styles.pageIndicatorTop']) {
+    styleUpdates.pageIndicatorTop = frontmatter['presentation.styles.pageIndicatorTop'];
+  }
+  if (frontmatter['presentation.styles.pageIndicatorRight']) {
+    styleUpdates.pageIndicatorRight = frontmatter['presentation.styles.pageIndicatorRight'];
+  }
+  if (frontmatter['presentation.styles.pageIndicatorFontSize']) {
+    styleUpdates.pageIndicatorFontSize = frontmatter['presentation.styles.pageIndicatorFontSize'];
+  }
+  if (frontmatter['presentation.styles.pageIndicatorOpacity'] !== undefined) {
+    styleUpdates.pageIndicatorOpacity = parseFloat(frontmatter['presentation.styles.pageIndicatorOpacity']);
+  }
+  if (frontmatter['presentation.styles.pageIndicatorPaddingX']) {
+    styleUpdates.pageIndicatorPaddingX = frontmatter['presentation.styles.pageIndicatorPaddingX'];
+  }
+  if (frontmatter['presentation.styles.pageIndicatorPaddingY']) {
+    styleUpdates.pageIndicatorPaddingY = frontmatter['presentation.styles.pageIndicatorPaddingY'];
+  }
+  if (frontmatter['presentation.styles.pageIndicatorBgColor']) {
+    styleUpdates.pageIndicatorBgColor = frontmatter['presentation.styles.pageIndicatorBgColor'];
+  }
+  if (frontmatter['presentation.styles.pageIndicatorTextColor']) {
+    styleUpdates.pageIndicatorTextColor = frontmatter['presentation.styles.pageIndicatorTextColor'];
+  }
+  
+  if (Object.keys(styleUpdates).length > 0) {
+    updateConfigPart('styles', styleUpdates);
+  }
+
+  // Load typography settings
+  const typographyUpdates = {};
+  
+  if (frontmatter['presentation.typography.paragraphSpacing.before'] !== undefined) {
+    if (!typographyUpdates.paragraphSpacing) typographyUpdates.paragraphSpacing = {};
+    typographyUpdates.paragraphSpacing.before = parseFloat(frontmatter['presentation.typography.paragraphSpacing.before']);
+  }
+  if (frontmatter['presentation.typography.paragraphSpacing.after'] !== undefined) {
+    if (!typographyUpdates.paragraphSpacing) typographyUpdates.paragraphSpacing = {};
+    typographyUpdates.paragraphSpacing.after = parseFloat(frontmatter['presentation.typography.paragraphSpacing.after']);
+  }
+  if (frontmatter['presentation.typography.headingSpacing.before'] !== undefined) {
+    if (!typographyUpdates.headingSpacing) typographyUpdates.headingSpacing = {};
+    typographyUpdates.headingSpacing.before = parseFloat(frontmatter['presentation.typography.headingSpacing.before']);
+  }
+  if (frontmatter['presentation.typography.headingSpacing.after'] !== undefined) {
+    if (!typographyUpdates.headingSpacing) typographyUpdates.headingSpacing = {};
+    typographyUpdates.headingSpacing.after = parseFloat(frontmatter['presentation.typography.headingSpacing.after']);
+  }
+  if (frontmatter['presentation.typography.indentation.firstLine'] !== undefined) {
+    if (!typographyUpdates.indentation) typographyUpdates.indentation = {};
+    typographyUpdates.indentation.firstLine = parseFloat(frontmatter['presentation.typography.indentation.firstLine']);
+  }
+  if (frontmatter['presentation.typography.indentation.blockQuote'] !== undefined) {
+    if (!typographyUpdates.indentation) typographyUpdates.indentation = {};
+    typographyUpdates.indentation.blockQuote = parseFloat(frontmatter['presentation.typography.indentation.blockQuote']);
+  }
+  if (frontmatter['presentation.typography.listIndent'] !== undefined) {
+    typographyUpdates.listIndent = parseFloat(frontmatter['presentation.typography.listIndent']);
+  }
+  if (frontmatter['presentation.typography.textAlign']) {
+    typographyUpdates.textAlign = frontmatter['presentation.typography.textAlign'];
+  }
+
+  if (Object.keys(typographyUpdates).length > 0) {
+    updateConfigPart('typography', typographyUpdates);
+  }
+
+  // Load Smart List Column Settings
+  const smartListUpdates = {};
+  if (frontmatter['presentation.smartList.twoColumnThreshold'] !== undefined) {
+    smartListUpdates.twoColumnThreshold = parseInt(frontmatter['presentation.smartList.twoColumnThreshold']);
+  }
+  if (frontmatter['presentation.smartList.threeColumnThreshold'] !== undefined) {
+    smartListUpdates.threeColumnThreshold = parseInt(frontmatter['presentation.smartList.threeColumnThreshold']);
+  }
+  if (Object.keys(smartListUpdates).length > 0) {
+    updateConfigPart('smartList', smartListUpdates);
+  }
+
+  // Reload UI to reflect changes
+  if (domElements) {
+    reloadUI(domElements);
+  }
+
+  return currentConfig;
+}
+
+/**
+ * Sync UI values back to configuration
+ */
+function syncUIToConfig(domElements) {
+  console.log('[PresentationConfig] Syncing UI to config...', domElements);
+  
+  // Update fonts
+  updateConfigPart('fonts', {
+    heading: domElements.fontHeading?.value,
+    body: domElements.fontBody?.value,
+    code: domElements.fontCode?.value
+  });
+
+  // Update colors
+  updateConfigPart('colors', {
+    primary: domElements.colorPrimary?.value,
+    accent: domElements.colorAccent?.value,
+    background: domElements.colorBackground?.value,
+    text: domElements.colorText?.value
+  });
+
+  // Update animations
+  updateConfigPart('animations', {
+    slideTransition: domElements.animationTransition?.value,
+    duration: parseFloat(domElements.animationDuration?.value || currentConfig.animations.duration)
+  });
+
+  // Update font sizes
+  updateConfigPart('fontSizes', {
+    h1: {
+      min: parseFloat(domElements.fontSizeH1Min?.value || currentConfig.fontSizes.h1.min),
+      base: parseFloat(domElements.fontSizeH1Base?.value || currentConfig.fontSizes.h1.base),
+      max: parseFloat(domElements.fontSizeH1Max?.value || currentConfig.fontSizes.h1.max)
+    },
+    h2: {
+      min: parseFloat(domElements.fontSizeH2Min?.value || currentConfig.fontSizes.h2.min),
+      base: parseFloat(domElements.fontSizeH2Base?.value || currentConfig.fontSizes.h2.base),
+      max: parseFloat(domElements.fontSizeH2Max?.value || currentConfig.fontSizes.h2.max)
+    },
+    text: {
+      min: parseFloat(domElements.fontSizeTextMin?.value || currentConfig.fontSizes.text.min),
+      base: parseFloat(domElements.fontSizeTextBase?.value || currentConfig.fontSizes.text.base),
+      max: parseFloat(domElements.fontSizeTextMax?.value || currentConfig.fontSizes.text.max)
+    }
+  });
+
+  // Update line height and UI styles
+  const currentStyles = currentConfig.styles || CONFIG_PRESETS.default.config.styles;
+  updateConfigPart('styles', {
+    ...currentStyles,
+    lineHeight: {
+      heading: parseFloat(domElements.lineHeightHeading?.value || currentStyles.lineHeight.heading),
+      body: parseFloat(domElements.lineHeightBody?.value || currentStyles.lineHeight.body)
+    },
+    // UI & Visual Effects
+    previewOpacity: parseFloat(domElements.previewOpacity?.value || currentStyles.previewOpacity),
+    overlayBlur: `${domElements.overlayBlur?.value || parseInt(currentStyles.overlayBlur)}px`,
+    navBorderWidth: `${domElements.navBorderWidth?.value || parseInt(currentStyles.navBorderWidth)}px`,
+    backdropGradientSpread: `${domElements.backdropSpread?.value || parseInt(currentStyles.backdropGradientSpread)}%`,
+    backdropBlur: `${domElements.backdropBlur?.value || parseInt(currentStyles.backdropBlur)}px`,
+    // Border Widths
+    headingAccentBorderWidth: `${domElements.headingBorderWidth?.value || parseInt(currentStyles.headingAccentBorderWidth)}px`,
+    blockquoteBorderWidth: `${domElements.blockquoteBorderWidth?.value || parseInt(currentStyles.blockquoteBorderWidth)}px`,
+    imageBorderWidth: `${domElements.imageBorderWidth?.value || parseInt(currentStyles.imageBorderWidth)}px`,
+    linkUnderlineWidth: `${domElements.linkUnderlineWidth?.value || parseInt(currentStyles.linkUnderlineWidth)}px`,
+    tableBorderWidth: `${domElements.tableBorderWidth?.value || parseInt(currentStyles.tableBorderWidth)}px`,
+    hrBorderWidth: `${domElements.hrBorderWidth?.value || parseInt(currentStyles.hrBorderWidth)}px`,
+    // Page Indicator
+    pageIndicatorTop: `${domElements.pageIndicatorTop?.value || parseInt(currentStyles.pageIndicatorTop)}px`,
+    pageIndicatorRight: `${domElements.pageIndicatorRight?.value || parseInt(currentStyles.pageIndicatorRight)}px`,
+    pageIndicatorFontSize: `${domElements.pageIndicatorFontSize?.value || parseFloat(currentStyles.pageIndicatorFontSize)}rem`,
+    pageIndicatorOpacity: parseFloat(domElements.pageIndicatorOpacity?.value || currentStyles.pageIndicatorOpacity),
+    pageIndicatorPaddingX: `${domElements.pageIndicatorPaddingX?.value || parseInt(currentStyles.pageIndicatorPaddingX)}px`,
+    pageIndicatorPaddingY: `${domElements.pageIndicatorPaddingY?.value || parseInt(currentStyles.pageIndicatorPaddingY)}px`,
+    pageIndicatorBgColor: domElements.pageIndicatorBgColor?.value || currentStyles.pageIndicatorBgColor,
+    pageIndicatorTextColor: domElements.pageIndicatorTextColor?.value || currentStyles.pageIndicatorTextColor
+  });
+
+  // Update typography (use current config as fallback)
+  const currentTypography = currentConfig.typography || CONFIG_PRESETS.default.config.typography;
+  
+  updateTypography({
+    paragraphSpacing: {
+      before: parseFloat(domElements.paragraphBefore?.value || currentTypography.paragraphSpacing.before),
+      after: parseFloat(domElements.paragraphAfter?.value || currentTypography.paragraphSpacing.after)
+    },
+    headingSpacing: {
+      before: parseFloat(domElements.headingBefore?.value || currentTypography.headingSpacing.before),
+      after: parseFloat(domElements.headingAfter?.value || currentTypography.headingSpacing.after)
+    },
+    indentation: {
+      firstLine: parseFloat(domElements.indentFirst?.value || currentTypography.indentation.firstLine),
+      hanging: currentTypography.indentation.hanging || 0,
+      blockQuote: parseFloat(domElements.indentBlockquote?.value || currentTypography.indentation.blockQuote)
+    },
+    listIndent: parseFloat(domElements.listIndent?.value || currentTypography.listIndent),
+    textAlign: domElements.textAlign?.value || currentTypography.textAlign
+  });
+
+  // Update Smart List Column Settings
+  const currentSmartList = currentConfig.smartList || CONFIG_PRESETS.default.config.smartList;
+  updateConfigPart('smartList', {
+    twoColumnThreshold: parseInt(domElements.smartListTwoColumn?.value || currentSmartList.twoColumnThreshold),
+    threeColumnThreshold: parseInt(domElements.smartListThreeColumn?.value || currentSmartList.threeColumnThreshold)
+  });
+  
+  // Update Content Layout & Positioning Settings
+  const currentLayout = currentConfig.layout || CONFIG_PRESETS.default.config.layout;
+  updateConfigPart('layout', {
+    contentPadding: {
+      small: parseInt(domElements.contentPaddingSmall?.value || currentLayout.contentPadding.small),
+      large: parseInt(domElements.contentPaddingLarge?.value || currentLayout.contentPadding.large),
+      ultra: parseInt(domElements.contentPaddingUltra?.value || currentLayout.contentPadding.ultra)
+    },
+    contentAlignment: {
+      horizontal: domElements.contentAlignHorizontal?.value || currentLayout.contentAlignment.horizontal,
+      vertical: domElements.contentAlignVertical?.value || currentLayout.contentAlignment.vertical
+    }
+  });
+  
+  console.log('[PresentationConfig] ✅ UI synced to config successfully');
+
+  // Trigger update callback
+  if (uiCallbacks.onUpdate) {
+    console.log('[PresentationConfig] Triggering onUpdate callback...');
+    uiCallbacks.onUpdate();
+  }
+}
+
+/**
+ * Setup preset selector listener
+ */
+function setupPresetListener(domElements) {
+  if (domElements.presetSelector) {
+    domElements.presetSelector.addEventListener('change', (e) => {
+      loadPreset(e.target.value);
+      loadConfigToUI(domElements);
+      
+      if (uiCallbacks.onUpdate) {
+        uiCallbacks.onUpdate();
+      }
+      
+      if (uiCallbacks.setStatus) {
+        uiCallbacks.setStatus(`Loaded preset: ${e.target.value}`, 'online');
+      }
+    });
+  }
+}
+
+/**
+ * Setup font change listeners
+ */
+function setupFontListeners(domElements) {
+  [domElements.fontHeading, domElements.fontBody, domElements.fontCode].forEach(select => {
+    if (select) {
+      // Real-time update on change
+      select.addEventListener('change', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(select);
+    }
+  });
+}
+
+/**
+ * Setup color change listeners
+ */
+function setupColorListeners(domElements) {
+  [domElements.colorPrimary, domElements.colorAccent, domElements.colorBackground, domElements.colorText].forEach(input => {
+    if (input) {
+      // Real-time update on input
+      input.addEventListener('input', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(input);
+    }
+  });
+}
+
+/**
+ * Setup animation change listeners
+ */
+function setupAnimationListeners(domElements) {
+  [domElements.animationTransition, domElements.animationDuration].forEach(input => {
+    if (input) {
+      // Real-time update on change/input
+      input.addEventListener('input', () => {
+        syncUIToConfig(domElements);
+      });
+      input.addEventListener('change', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(input);
+    }
+  });
+}
+
+/**
+ * Setup font size and line height change listeners
+ */
+function setupFontSizeListeners(domElements) {
+  [
+    domElements.fontSizeH1Min, domElements.fontSizeH1Base, domElements.fontSizeH1Max,
+    domElements.fontSizeH2Min, domElements.fontSizeH2Base, domElements.fontSizeH2Max,
+    domElements.fontSizeTextMin, domElements.fontSizeTextBase, domElements.fontSizeTextMax,
+    domElements.lineHeightHeading, domElements.lineHeightBody
+  ].forEach(input => {
+    if (input) {
+      // Real-time update on input
+      input.addEventListener('input', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(input);
+    }
+  });
+}
+
+/**
+ * Setup UI styles listeners
+ */
+function setupUIStylesListeners(domElements) {
+  [
+    domElements.previewOpacity, domElements.overlayBlur, domElements.navBorderWidth,
+    domElements.backdropSpread, domElements.backdropBlur,
+    domElements.headingBorderWidth, domElements.blockquoteBorderWidth,
+    domElements.imageBorderWidth, domElements.linkUnderlineWidth,
+    domElements.tableBorderWidth, domElements.hrBorderWidth,
+    domElements.pageIndicatorTop, domElements.pageIndicatorRight,
+    domElements.pageIndicatorFontSize, domElements.pageIndicatorOpacity,
+    domElements.pageIndicatorPaddingX, domElements.pageIndicatorPaddingY,
+    domElements.pageIndicatorBgColor, domElements.pageIndicatorTextColor,
+    domElements.smartListTwoColumn, domElements.smartListThreeColumn
+  ].forEach(input => {
+    if (input) {
+      // Real-time update on input
+      input.addEventListener('input', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(input);
+    }
+  });
+}
+
+/**
+ * Setup visual feedback system
+ * Highlights stage elements when hovering over related settings
+ */
+function setupVisualFeedback(inputElement) {
+  if (!inputElement || !inputElement.id) return;
+  
+  const feedbackMap = {
+    // Font settings -> all text elements
+    'fontHeading': { selector: 'h1, h2, h3, h4, h5, h6', type: 'content' },
+    'fontBody': { selector: 'p, li, blockquote', type: 'content' },
+    'fontCode': { selector: 'code, pre', type: 'content' },
+    
+    // Font sizes -> specific headings
+    'fontSizeH1Min': { selector: 'h1', type: 'content' },
+    'fontSizeH1Base': { selector: 'h1', type: 'content' },
+    'fontSizeH1Max': { selector: 'h1', type: 'content' },
+    'fontSizeH2Min': { selector: 'h2', type: 'content' },
+    'fontSizeH2Base': { selector: 'h2', type: 'content' },
+    'fontSizeH2Max': { selector: 'h2', type: 'content' },
+    'fontSizeTextMin': { selector: 'p, li', type: 'content' },
+    'fontSizeTextBase': { selector: 'p, li', type: 'content' },
+    'fontSizeTextMax': { selector: 'p, li', type: 'content' },
+    
+    // Colors -> elements with those colors
+    'colorPrimary': { selector: 'h1, a', type: 'content' },
+    'colorAccent': { selector: '.accent, .badge', type: 'content' },
+    'colorBackground': { selector: '#stage', type: 'content' },
+    'colorText': { selector: 'p, li, span', type: 'content' },
+    
+    // Line height
+    'lineHeightHeading': { selector: 'h1, h2, h3', type: 'content' },
+    'lineHeightBody': { selector: 'p, li', type: 'content' },
+    
+    // Border widths
+    'headingBorderWidth': { selector: 'h1, h2, h3', type: 'content' },
+    'blockquoteBorderWidth': { selector: 'blockquote', type: 'content' },
+    'imageBorderWidth': { selector: 'img', type: 'content' },
+    'linkUnderlineWidth': { selector: 'a', type: 'content' },
+    'tableBorderWidth': { selector: 'table, td, th', type: 'content' },
+    'hrBorderWidth': { selector: 'hr', type: 'content' },
+    
+    // Typography
+    'paragraphBefore': { selector: 'p', type: 'content' },
+    'paragraphAfter': { selector: 'p', type: 'content' },
+    'headingBefore': { selector: 'h1, h2, h3', type: 'content' },
+    'headingAfter': { selector: 'h1, h2, h3', type: 'content' },
+    'indentBlockquote': { selector: 'blockquote', type: 'content' },
+    'listIndent': { selector: 'ul, ol, li', type: 'content' },
+    'textAlign': { selector: 'p, h1, h2, h3', type: 'content' },
+    
+    // Smart lists
+    'smartListTwoColumn': { selector: 'ul, ol', type: 'content' },
+    'smartListThreeColumn': { selector: 'ul, ol', type: 'content' },
+    
+    // Content Layout
+    'contentPaddingSmall': { selector: '.scene', type: 'content' },
+    'contentPaddingLarge': { selector: '.scene', type: 'content' },
+    'contentPaddingUltra': { selector: '.scene', type: 'content' },
+    'contentAlignHorizontal': { selector: '#slideContainer, .scene', type: 'content' },
+    'contentAlignVertical': { selector: '#slideContainer, .scene', type: 'content' },
+    
+    // UI Elements
+    'previewOpacity': { selector: '.scene:not(.active)', type: 'ui' },
+    'overlayBlur': { selector: '#pauseOverlay', type: 'ui' },
+    'navBorderWidth': { selector: '.nav-btn', type: 'ui' },
+    'backdropSpread': { selector: '.gradient-backdrop', type: 'ui' },
+    'backdropBlur': { selector: '.gradient-backdrop', type: 'ui' },
+    'pageIndicatorTop': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorRight': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorFontSize': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorOpacity': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorPaddingX': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorPaddingY': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorBgColor': { selector: '#slideCounter', type: 'ui' },
+    'pageIndicatorTextColor': { selector: '#slideCounter', type: 'ui' }
+  };
+  
+  const mapping = feedbackMap[inputElement.id];
+  if (!mapping) return;
+  
+  // Mouse enter - highlight elements
+  inputElement.addEventListener('mouseenter', () => {
+    const stage = document.getElementById('stage');
+    if (!stage) return;
+    
+    const elements = stage.querySelectorAll(mapping.selector);
+    elements.forEach(el => {
+      // Add highlight class based on type
+      if (mapping.type === 'content') {
+        el.style.outline = '2px solid rgba(96, 165, 250, 0.5)'; // Blue for content
+        el.style.outlineOffset = '4px';
+        el.style.transition = 'outline 0.2s ease';
+      } else {
+        el.style.outline = '2px solid rgba(168, 85, 247, 0.5)'; // Purple for UI
+        el.style.outlineOffset = '4px';
+        el.style.transition = 'outline 0.2s ease';
+      }
+    });
+    
+    // Add visual feedback to the input itself
+    const color = mapping.type === 'content' ? 'rgba(96, 165, 250, 0.3)' : 'rgba(168, 85, 247, 0.3)';
+    inputElement.style.backgroundColor = color;
+    inputElement.style.transition = 'background-color 0.2s ease';
+  });
+  
+  // Mouse leave - remove highlight
+  inputElement.addEventListener('mouseleave', () => {
+    const stage = document.getElementById('stage');
+    if (!stage) return;
+    
+    const elements = stage.querySelectorAll(mapping.selector);
+    elements.forEach(el => {
+      el.style.outline = '';
+      el.style.outlineOffset = '';
+    });
+    
+    // Remove input highlight
+    inputElement.style.backgroundColor = '';
+  });
+}
+
+/**
+ * Setup typography change listeners
+ */
+function setupTypographyListeners(domElements) {
+  [
+    domElements.paragraphBefore, domElements.paragraphAfter,
+    domElements.headingBefore, domElements.headingAfter,
+    domElements.indentFirst, domElements.indentBlockquote,
+    domElements.listIndent, domElements.textAlign
+  ].forEach(input => {
+    if (input) {
+      // Real-time update on input
+      input.addEventListener('input', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(input);
+    }
+  });
+}
+
+/**
+ * Setup layout change listeners
+ */
+function setupLayoutListeners(domElements) {
+  [
+    domElements.contentPaddingSmall, domElements.contentPaddingLarge, domElements.contentPaddingUltra,
+    domElements.contentAlignHorizontal, domElements.contentAlignVertical
+  ].forEach(input => {
+    if (input) {
+      // Real-time update on input
+      input.addEventListener('input', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Real-time update on change (for select elements)
+      input.addEventListener('change', () => {
+        syncUIToConfig(domElements);
+      });
+      
+      // Visual feedback on hover
+      setupVisualFeedback(input);
+    }
+  });
+}
+
+/**
+ * Setup Save and Reset buttons
+ */
+function setupActionButtons(domElements) {
+  // Save button
+  if (domElements.saveSettingsBtn) {
+    domElements.saveSettingsBtn.addEventListener('click', () => {
+      if (uiCallbacks.onSave) {
+        uiCallbacks.onSave(currentConfig, domElements.presetSelector?.value);
+      }
+      
+      if (uiCallbacks.setStatus) {
+        uiCallbacks.setStatus('Settings saved to frontmatter', 'online');
+      }
+    });
+  }
+
+  // Reset button
+  if (domElements.resetSettingsBtn) {
+    domElements.resetSettingsBtn.addEventListener('click', () => {
+      resetConfig();
+      loadConfigToUI(domElements);
+      
+      if (domElements.presetSelector) {
+        domElements.presetSelector.value = 'default';
+      }
+      
+      if (uiCallbacks.onUpdate) {
+        uiCallbacks.onUpdate();
+      }
+      
+      if (uiCallbacks.setStatus) {
+        uiCallbacks.setStatus('Settings reset to default', 'online');
+      }
+    });
+  }
+}
+
+// Auto-apply on load
+if (typeof window !== 'undefined') {
+  window.addEventListener('DOMContentLoaded', () => {
+    applyConfigToDOM();
+  });
+}
+

src/renderer/js/slide-editor.js

@@ -0,0 +1,831 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Markdown Presenter - Slide Editor
+// In-Presentation Slide Editing System with Drag & Drop
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 2.1.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { DragDropManager } from './drag-drop-manager.js';
+import { PersistentStorage } from '../../shared/persistent-storage.js';
+import { ContentFingerprint } from '../../shared/content-fingerprint.js';
+import { setDisplayMode, getDisplayMode } from './presentation-config.js';
+import { 
+    switchToEditorMode, 
+    switchToPresentationMode,
+    getModeManager 
+} from './mode-manager.js';
+
+/**
+ * Slide Editor - แก้ไขสไลด์แบบ inline ใน Presentation Mode
+ * พร้อมระบบลากย้ายตำแหน่งและบันทึกถาวร
+ */
+export class SlideEditor {
+    constructor() {
+        this.isEditMode = false;
+        this.isDragMode = false;
+        this.currentSlideIndex = -1;
+        this.currentFilePath = null;
+        this.slideOverrides = new Map(); // เก็บการแก้ไขแยกตามสไลด์
+        this.originalContent = null;
+        this.hasUnsavedChanges = false;
+        
+        // DOM Elements
+        this.editBtn = document.getElementById('editSlideBtn');
+        this.saveBtn = document.getElementById('saveSlideBtn');
+        this.cancelBtn = document.getElementById('cancelEditBtn');
+        this.stage = document.getElementById('stage');
+        
+        // Position Controls
+        this.positionControls = document.getElementById('positionControls');
+        this.toggleSafeZoneBtn = document.getElementById('toggleSafeZoneBtn');
+        this.toggleSnapGridBtn = document.getElementById('toggleSnapGridBtn');
+        this.resetPositionsBtn = document.getElementById('resetPositionsBtn');
+        this.exportSettingsBtn = document.getElementById('exportSettingsBtn');
+        this.positionIndicator = document.getElementById('positionIndicator');
+        
+        // Managers
+        this.dragDropManager = new DragDropManager();
+        this.persistentStorage = new PersistentStorage();
+        
+        this.init();
+    }
+
+    /**
+     * Initialize editor
+     */
+    init() {
+        if (!this.editBtn || !this.saveBtn || !this.cancelBtn) {
+            console.warn('[SlideEditor] Required buttons not found');
+            return;
+        }
+
+        // Event listeners
+        this.editBtn.addEventListener('click', () => this.toggleEditMode());
+        this.saveBtn.addEventListener('click', () => this.saveChanges());
+        this.cancelBtn.addEventListener('click', () => this.cancelEdit());
+        
+        // Position control listeners
+        if (this.toggleSafeZoneBtn) {
+            this.toggleSafeZoneBtn.addEventListener('click', () => this.toggleSafeZone());
+        }
+        if (this.toggleSnapGridBtn) {
+            this.toggleSnapGridBtn.addEventListener('click', () => this.toggleSnapGrid());
+        }
+        if (this.resetPositionsBtn) {
+            this.resetPositionsBtn.addEventListener('click', () => this.resetAllPositions());
+        }
+        if (this.exportSettingsBtn) {
+            this.exportSettingsBtn.addEventListener('click', () => this.exportAllSettings());
+        }
+
+        // Keyboard shortcuts
+        document.addEventListener('keydown', (e) => {
+            if (!this.isEditMode) return;
+
+            // Ctrl/Cmd + S = Save
+            if ((e.ctrlKey || e.metaKey) && e.key === 's') {
+                e.preventDefault();
+                this.saveChanges();
+            }
+
+            // ESC = Cancel
+            if (e.key === 'Escape') {
+                e.preventDefault();
+                this.cancelEdit();
+            }
+        });
+
+        console.log('[SlideEditor] Initialized');
+    }
+
+    /**
+     * Show edit button when in presentation mode
+     */
+    showEditButton() {
+        if (this.editBtn) {
+            this.editBtn.classList.remove('hidden');
+        }
+    }
+
+    /**
+     * Hide edit button
+     */
+    hideEditButton() {
+        if (this.editBtn) {
+            this.editBtn.classList.add('hidden');
+        }
+        this.exitEditMode();
+    }
+
+    /**
+     * Set current slide index
+     */
+    setCurrentSlide(index) {
+        this.currentSlideIndex = index;
+    }
+
+    /**
+     * Toggle edit mode
+     */
+    toggleEditMode() {
+        if (this.isEditMode) {
+            this.exitEditMode();
+        } else {
+            this.enterEditMode();
+        }
+    }
+
+    /**
+     * Enter edit mode
+     */
+    /**
+     * Enter edit mode
+     */
+    enterEditMode() {
+        if (this.currentSlideIndex < 0) {
+            console.warn('[SlideEditor] No slide selected');
+            return;
+        }
+
+        // สลับไปโหมด editor และปิดโหมดอื่นทั้งหมด
+        switchToEditorMode();
+
+        this.isEditMode = true;
+        this.hasUnsavedChanges = false;
+
+        // Save original content
+        const activeScene = this.stage.querySelector('.scene.active');
+        if (!activeScene) {
+            console.warn('[SlideEditor] No active scene found');
+            return;
+        }
+
+        this.originalContent = activeScene.cloneNode(true);
+        
+        // Mode Manager จัดการ Smart Layout แล้ว ไม่ต้อง detach ที่นี่
+
+        // Make content editable
+        this.makeContentEditable(activeScene);
+
+        // Update UI
+        this.stage.classList.add('slide-editable');
+        this.editBtn.classList.add('active');
+        this.showEditIndicator();
+        
+        // Mode Manager จัดการ Safe Zone แล้ว ไม่ต้องแสดงที่นี่
+
+        console.log(`[SlideEditor] Edit mode entered for slide ${this.currentSlideIndex}`);
+    }
+
+    /**
+     * Exit edit mode (with unsaved changes check)
+     */
+    async exitEditMode() {
+        if (!this.isEditMode) return;
+
+        // ถ้ามีการแก้ไขที่ยังไม่บันทึก ให้ถามผู้ใช้
+        if (this.hasUnsavedChanges) {
+            const result = await this.showExitConfirmation('Edit Mode', 'You have unsaved changes.');
+            
+            if (result === 'cancel') {
+                // ยกเลิก ไม่ออกจาก Edit Mode
+                return;
+            } else if (result === 'save') {
+                // บันทึกก่อนออก
+                await this.saveCurrentSlide();
+            }
+            // ถ้าเลือก 'discard' ก็ออกเลยโดยไม่บันทึก
+        }
+
+        this.isEditMode = false;
+
+        // กลับไปโหมด presentation และปิดโหมดอื่นทั้งหมด
+        switchToPresentationMode();
+
+        // Remove contenteditable
+        const activeScene = this.stage.querySelector('.scene.active');
+        if (activeScene) {
+            this.makeContentNonEditable(activeScene);
+        }
+
+        // Update UI
+        this.stage.classList.remove('slide-editable');
+        this.editBtn.classList.remove('active');
+        this.hideEditIndicator();
+        this.hideSaveButtons();
+        
+        // Mode Manager จัดการ Safe Zone และ Smart Layout แล้ว
+
+        this.originalContent = null;
+        this.hasUnsavedChanges = false;
+
+        console.log('[SlideEditor] Edit mode exited');
+    }
+
+    /**
+     * Show exit confirmation dialog
+     * @param {string} modeName - ชื่อโหมด
+     * @param {string} message - ข้อความเพิ่มเติม
+     * @returns {Promise<string>} 'save', 'discard', หรือ 'cancel'
+     */
+    async showExitConfirmation(modeName, message = '') {
+        return new Promise((resolve) => {
+            const dialog = document.createElement('div');
+            dialog.className = 'exit-confirmation-dialog';
+            dialog.innerHTML = `
+                <div class="exit-confirmation-overlay"></div>
+                <div class="exit-confirmation-content">
+                    <div class="exit-confirmation-header">
+                        <h3>Exit ${modeName}?</h3>
+                    </div>
+                    <div class="exit-confirmation-body">
+                        <p class="warning-text">${message}</p>
+                        <p>Do you want to save your changes?</p>
+                    </div>
+                    <div class="exit-confirmation-footer">
+                        <button class="btn-exit-save" data-action="save">
+                            Save & Exit
+                        </button>
+                        <button class="btn-exit-discard" data-action="discard">
+                            Discard Changes
+                        </button>
+                        <button class="btn-exit-cancel" data-action="cancel">
+                            Cancel
+                        </button>
+                    </div>
+                </div>
+            `;
+            
+            document.body.appendChild(dialog);
+            
+            // Handle button clicks
+            dialog.querySelectorAll('button').forEach(btn => {
+                btn.addEventListener('click', () => {
+                    const action = btn.dataset.action;
+                    document.body.removeChild(dialog);
+                    resolve(action);
+                });
+            });
+            
+            // ESC to cancel
+            const escHandler = (e) => {
+                if (e.key === 'Escape') {
+                    document.body.removeChild(dialog);
+                    document.removeEventListener('keydown', escHandler);
+                    resolve('cancel');
+                }
+            };
+            document.addEventListener('keydown', escHandler);
+        });
+    }
+
+    /**
+     * Make scene content editable
+     */
+    makeContentEditable(scene) {
+        // Find all editable elements
+        const editableElements = scene.querySelectorAll('h1, h2, h3, h4, h5, h6, p, li, blockquote');
+        
+        editableElements.forEach((el, index) => {
+            el.setAttribute('contenteditable', 'true');
+            el.setAttribute('data-editable-id', `edit-${index}`);
+            el.setAttribute('data-placeholder', 'Click to edit...');
+            
+            // Track changes
+            el.addEventListener('input', () => this.onContentChange());
+            el.addEventListener('blur', () => this.onContentChange());
+        });
+    }
+
+    /**
+     * Remove contenteditable
+     */
+    makeContentNonEditable(scene) {
+        const editableElements = scene.querySelectorAll('[contenteditable="true"]');
+        
+        editableElements.forEach(el => {
+            el.removeAttribute('contenteditable');
+            el.removeAttribute('data-editable-id');
+            el.removeAttribute('data-placeholder');
+        });
+    }
+
+    /**
+     * Handle content change
+     */
+    onContentChange() {
+        if (!this.hasUnsavedChanges) {
+            this.hasUnsavedChanges = true;
+            this.showSaveButtons();
+        }
+    }
+
+    /**
+     * Save changes to current slide
+     */
+    saveChanges() {
+        if (!this.isEditMode || this.currentSlideIndex < 0) return;
+
+        const activeScene = this.stage.querySelector('.scene.active');
+        if (!activeScene) return;
+
+        // Extract edited content
+        const editedContent = this.extractEditedContent(activeScene);
+
+        // Save to overrides map
+        this.slideOverrides.set(this.currentSlideIndex, {
+            timestamp: Date.now(),
+            content: editedContent,
+            html: activeScene.innerHTML
+        });
+
+        console.log(`[SlideEditor] Saved changes for slide ${this.currentSlideIndex}`, editedContent);
+
+        // Exit edit mode
+        this.exitEditMode();
+
+        // Show success notification
+        this.showNotification('✓ Slide saved', 'success');
+    }
+
+    /**
+     * Cancel edit and revert changes
+     */
+    cancelEdit() {
+        if (!this.isEditMode || !this.originalContent) return;
+
+        const activeScene = this.stage.querySelector('.scene.active');
+        if (activeScene && this.originalContent) {
+            // Restore original content
+            activeScene.parentNode.replaceChild(this.originalContent.cloneNode(true), activeScene);
+            
+            // Re-add active class
+            const restoredScene = this.stage.querySelector('.scene[data-scene]');
+            if (restoredScene) {
+                restoredScene.classList.add('active');
+            }
+        }
+
+        this.exitEditMode();
+        this.showNotification('✗ Changes cancelled', 'warning');
+    }
+
+    /**
+     * Extract edited content from scene
+     */
+    extractEditedContent(scene) {
+        const content = {};
+        
+        // Extract text from editable elements
+        const editables = scene.querySelectorAll('[data-editable-id]');
+        editables.forEach(el => {
+            const id = el.getAttribute('data-editable-id');
+            content[id] = {
+                tag: el.tagName.toLowerCase(),
+                text: el.textContent.trim(),
+                html: el.innerHTML
+            };
+        });
+
+        return content;
+    }
+
+    /**
+     * Apply saved overrides to a slide
+     */
+    applyOverrides(slideIndex, scene) {
+        if (!this.slideOverrides.has(slideIndex)) return false;
+
+        const override = this.slideOverrides.get(slideIndex);
+        
+        // Apply saved HTML
+        if (override.html) {
+            scene.innerHTML = override.html;
+            console.log(`[SlideEditor] Applied overrides to slide ${slideIndex}`);
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Check if slide has overrides
+     */
+    hasOverrides(slideIndex) {
+        return this.slideOverrides.has(slideIndex);
+    }
+
+    /**
+     * Get all overrides
+     */
+    getAllOverrides() {
+        return Array.from(this.slideOverrides.entries()).map(([index, data]) => ({
+            slideIndex: index,
+            ...data
+        }));
+    }
+
+    /**
+     * Clear override for specific slide
+     */
+    clearOverride(slideIndex) {
+        this.slideOverrides.delete(slideIndex);
+    }
+
+    /**
+     * Clear all overrides
+     */
+    clearAllOverrides() {
+        this.slideOverrides.clear();
+    }
+
+    /**
+     * Export overrides as JSON
+     */
+    exportOverrides() {
+        const data = this.getAllOverrides();
+        return JSON.stringify(data, null, 2);
+    }
+
+    /**
+     * Import overrides from JSON
+     */
+    importOverrides(jsonString) {
+        try {
+            const data = JSON.parse(jsonString);
+            data.forEach(item => {
+                this.slideOverrides.set(item.slideIndex, {
+                    timestamp: item.timestamp,
+                    content: item.content,
+                    html: item.html
+                });
+            });
+            console.log(`[SlideEditor] Imported ${data.length} overrides`);
+            return true;
+        } catch (error) {
+            console.error('[SlideEditor] Failed to import overrides:', error);
+            return false;
+        }
+    }
+
+    /**
+     * Show edit mode indicator
+     */
+    showEditIndicator() {
+        let indicator = document.getElementById('editModeIndicator');
+        if (!indicator) {
+            indicator = document.createElement('div');
+            indicator.id = 'editModeIndicator';
+            indicator.className = 'edit-mode-indicator';
+            indicator.textContent = '✎ Edit Mode';
+            this.stage.appendChild(indicator);
+        }
+    }
+
+    /**
+     * Hide edit mode indicator
+     */
+    hideEditIndicator() {
+        const indicator = document.getElementById('editModeIndicator');
+        if (indicator) {
+            indicator.remove();
+        }
+    }
+
+    /**
+     * Show save/cancel buttons
+     */
+    showSaveButtons() {
+        if (this.saveBtn) this.saveBtn.classList.remove('hidden');
+        if (this.cancelBtn) this.cancelBtn.classList.remove('hidden');
+    }
+
+    /**
+     * Hide save/cancel buttons
+     */
+    hideSaveButtons() {
+        if (this.saveBtn) this.saveBtn.classList.add('hidden');
+        if (this.cancelBtn) this.cancelBtn.classList.add('hidden');
+    }
+
+    /**
+     * Show notification
+     */
+    showNotification(message, type = 'info') {
+        // Create notification element
+        const notification = document.createElement('div');
+        notification.className = `slide-edit-notification notification-${type}`;
+        notification.textContent = message;
+        notification.style.cssText = `
+            position: fixed;
+            top: 5rem;
+            left: 50%;
+            transform: translateX(-50%);
+            z-index: 1000;
+            background: ${type === 'success' ? 'rgba(16, 185, 129, 0.95)' : 
+                         type === 'warning' ? 'rgba(245, 158, 11, 0.95)' : 
+                         'rgba(59, 130, 246, 0.95)'};
+            color: white;
+            padding: 0.75rem 1.5rem;
+            border-radius: 0.5rem;
+            font-weight: 600;
+            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
+            animation: slideDown 0.3s ease-out;
+        `;
+
+        document.body.appendChild(notification);
+
+        // Remove after 3 seconds
+        setTimeout(() => {
+            notification.style.animation = 'slideUp 0.3s ease-out';
+            setTimeout(() => notification.remove(), 300);
+        }, 3000);
+    }
+
+    /**
+     * Reset editor state
+     */
+    reset() {
+        this.exitEditMode();
+        this.exitDragMode();
+        this.currentSlideIndex = -1;
+        this.hideEditButton();
+        this.hidePositionControls();
+    }
+
+    // ═══════════════════════════════════════════════════════════════════════════
+    // DRAG & DROP METHODS
+    // ═══════════════════════════════════════════════════════════════════════════
+
+    /**
+     * เข้าสู่ Drag Mode
+     */
+    /**
+     * เข้าสู่ Drag Mode
+     */
+    enterDragMode() {
+        const activeScene = this.stage?.querySelector('.scene.active');
+        if (!activeScene) return;
+
+        // สลับไปโหมด editor และปิดโหมดอื่นทั้งหมด
+        switchToEditorMode();
+
+        this.isDragMode = true;
+        
+        // Mode Manager จัดการ Smart Layout แล้ว ไม่ต้อง detach ที่นี่
+        
+        this.dragDropManager.enableDragging(activeScene);
+        this.showPositionControls();
+        
+        // เปลี่ยนสีปุ่ม edit
+        if (this.editBtn) {
+            this.editBtn.style.background = 'rgba(139, 92, 246, 0.9)'; // สีม่วง
+        }
+        
+        this.showNotification('⊕ Drag Mode - ลากเพื่อย้ายตำแหน่งบรรทัด', 'info');
+    }
+
+    /**
+     * ออกจาก Drag Mode
+     */
+    exitDragMode() {
+        const activeScene = this.stage?.querySelector('.scene.active');
+        if (activeScene) {
+            this.dragDropManager.disableDragging(activeScene);
+        }
+
+        // กลับไปโหมด presentation และปิดโหมดอื่นทั้งหมด
+        switchToPresentationMode();
+
+        this.isDragMode = false;
+        this.hidePositionControls();
+        
+        // Mode Manager จัดการ Smart Layout แล้ว ไม่ต้อง reattach ที่นี่
+        
+        // คืนสีปุ่ม edit
+        if (this.editBtn) {
+            this.editBtn.style.background = '';
+        }
+    }
+
+    /**
+     * Toggle Drag Mode
+     */
+    toggleDragMode() {
+        if (this.isDragMode) {
+            this.exitDragMode();
+        } else {
+            // ออกจาก Edit Mode ก่อน (ถ้ากำลัง edit อยู่)
+            if (this.isEditMode) {
+                this.exitEditMode();
+            }
+            this.enterDragMode();
+        }
+    }
+
+    /**
+     * แสดง Position Controls
+     */
+    showPositionControls() {
+        if (this.positionControls) {
+            this.positionControls.classList.remove('hidden');
+        }
+    }
+
+    /**
+     * ซ่อน Position Controls
+     */
+    hidePositionControls() {
+        if (this.positionControls) {
+            this.positionControls.classList.add('hidden');
+        }
+    }
+
+    /**
+     * Toggle Safe Zone
+     */
+    toggleSafeZone() {
+        const isActive = this.dragDropManager.showSafeZone;
+        this.dragDropManager.toggleSafeZone(!isActive);
+        
+        if (this.toggleSafeZoneBtn) {
+            if (!isActive) {
+                this.toggleSafeZoneBtn.classList.add('active');
+                this.showNotification('✓ Safe Zone เปิด', 'success');
+            } else {
+                this.toggleSafeZoneBtn.classList.remove('active');
+                this.showNotification('✗ Safe Zone ปิด', 'info');
+            }
+        }
+    }
+
+    /**
+     * Toggle Snap to Grid
+     */
+    toggleSnapGrid() {
+        const isActive = this.dragDropManager.snapToGrid;
+        this.dragDropManager.toggleSnapToGrid(!isActive);
+        
+        if (this.toggleSnapGridBtn) {
+            if (!isActive) {
+                this.toggleSnapGridBtn.classList.add('active');
+                this.showNotification('✓ Snap to Grid เปิด', 'success');
+            } else {
+                this.toggleSnapGridBtn.classList.remove('active');
+                this.showNotification('✗ Snap to Grid ปิด', 'info');
+            }
+        }
+    }
+
+    /**
+     * รีเซ็ตตำแหน่งทั้งหมดของสไลด์ปัจจุบัน
+     */
+    resetAllPositions() {
+        if (!confirm('รีเซ็ตตำแหน่งและการแก้ไขทั้งหมดของสไลด์นี้?\n(การตั้งค่าจะถูกลบถาวร)')) {
+            return;
+        }
+
+        const activeScene = this.stage?.querySelector('.scene.active');
+        if (!activeScene) return;
+
+        // รีเซ็ตตำแหน่ง
+        const elements = activeScene.querySelectorAll('.draggable-content');
+        elements.forEach(element => {
+            this.dragDropManager.resetPosition(element);
+        });
+
+        // ลบการแก้ไขเนื้อหา
+        if (this.currentSlideIndex >= 0) {
+            this.slideOverrides.delete(this.currentSlideIndex);
+        }
+
+        // ลบจาก localStorage
+        if (this.currentFilePath && this.currentSlideIndex >= 0) {
+            this.persistentStorage.clearSlide(this.currentFilePath, this.currentSlideIndex);
+        }
+
+        // ลบข้อมูล positions จาก dragDropManager
+        this.dragDropManager.clearAllPositions();
+
+        this.showNotification('✓ รีเซ็ตทั้งหมดเรียบร้อย', 'success');
+    }
+
+    /**
+     * Export การตั้งค่าทั้งหมด
+     */
+    exportAllSettings() {
+        if (!this.currentFilePath) {
+            this.showNotification('��� กรุณาเปิดไฟล์ก่อน', 'warning');
+            return;
+        }
+
+        const totalSlides = this.getTotalSlides();
+        this.persistentStorage.downloadJSON(this.currentFilePath, totalSlides);
+        this.showNotification('✓ ส่งออกการตั้งค่าเรียบร้อย', 'success');
+    }
+
+    /**
+     * นับจำนวน slides ทั้งหมด
+     */
+    getTotalSlides() {
+        // ควร implement ตามโครงสร้างจริง
+        return 10; // placeholder
+    }
+
+    /**
+     * ตั้งค่าไฟล์ปัจจุบัน
+     */
+    setCurrentFile(filePath) {
+        this.currentFilePath = filePath;
+        this.persistentStorage.setCurrentFile(filePath);
+    }
+
+    /**
+     * Apply positions จาก storage
+     */
+    applyPositions(slideIndex, scene) {
+        if (!this.currentFilePath) return false;
+
+        const positions = this.persistentStorage.loadPositions(this.currentFilePath, slideIndex);
+        if (!positions) return false;
+
+        this.dragDropManager.loadPositions(positions);
+        return true;
+    }
+
+    /**
+     * Save positions ไปยัง storage
+     */
+    savePositions() {
+        if (!this.currentFilePath || this.currentSlideIndex < 0) return;
+
+        const positions = this.dragDropManager.exportPositions();
+        this.persistentStorage.savePositions(
+            this.currentFilePath,
+            this.currentSlideIndex,
+            positions
+        );
+    }
+
+    // ═══════════════════════════════════════════════════════════════════════════
+    // CONTENT FINGERPRINTING
+    // ═══════════════════════════════════════════════════════════════════════════
+
+    /**
+     * สร้าง fingerprint map สำหรับ slide
+     */
+    createFingerprintMap(scene) {
+        return ContentFingerprint.mapSlideElements(scene);
+    }
+
+    /**
+     * Match settings กับ content ใหม่
+     */
+    matchSettingsToContent(scene, savedSettings) {
+        const elementMap = this.createFingerprintMap(scene);
+        const matched = [];
+
+        elementMap.forEach(({ element, fingerprint }) => {
+            const setting = ContentFingerprint.match(fingerprint, savedSettings);
+            if (setting) {
+                matched.push({
+                    element,
+                    setting,
+                    confidence: setting.matchConfidence
+                });
+            }
+        });
+
+        return matched;
+    }
+}
+
+// CSS for notification animation
+const style = document.createElement('style');
+style.textContent = `
+@keyframes slideDown {
+    from {
+        opacity: 0;
+        transform: translate(-50%, -20px);
+    }
+    to {
+        opacity: 1;
+        transform: translate(-50%, 0);
+    }
+}
+
+@keyframes slideUp {
+    from {
+        opacity: 1;
+        transform: translate(-50%, 0);
+    }
+    to {
+        opacity: 0;
+        transform: translate(-50%, -20px);
+    }
+}
+`;
+document.head.appendChild(style);
+

src/renderer/js/templates.js

@@ -0,0 +1,431 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Video Templates
+// Multiple Professional Templates for Video Creation
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+// สีหลักที่ใช้ร่วมกันทุก template
+const SHARED_COLORS = {
+  primary: '#60a5fa',       // Blue
+  secondary: '#a855f7',     // Purple
+  background: '#0a1628',    // Dark blue-black
+  surface: '#132337',       // Dark blue-gray
+  text: '#e2e8f0',          // Light gray
+  textSecondary: '#94a3b8', // Medium gray
+  accent: '#06b6d4'         // Cyan
+};
+
+export const VIDEO_TEMPLATES = {
+  // ════════════════════════════════════════════════════════════════════════════
+  // Modern Template - Inter Font + Rounded Corners
+  // ════════════════════════════════════════════════════════════════════════════
+  modern: {
+    id: 'modern',
+    name: 'Modern',
+    description: 'Clean and professional design with gradient accents',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Inter', 'Segoe UI', sans-serif",
+      code: "'Source Code Pro', monospace"
+    },
+    animations: {
+      duration: 0.6,
+      easing: 'cubic-bezier(0.4, 0, 0.2, 1)',
+      fadeIn: 'fadeIn 0.6s ease-out',
+      slideUp: 'slideUp 0.6s ease-out'
+    },
+    styles: {
+      borderRadius: '1.25rem',
+      shadow: '0 20px 40px rgba(0, 0, 0, 0.3)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.2), rgba(168, 85, 247, 0.2))'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Classic Template - Serif Font + Traditional Style
+  // ════════════════════════════════════════════════════════════════════════════
+  classic: {
+    id: 'classic',
+    name: 'Classic',
+    description: 'Traditional elegant design with serif fonts',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Playfair Display', 'Georgia', serif",
+      code: "'Courier Prime', 'Courier New', monospace"
+    },
+    animations: {
+      duration: 0.8,
+      easing: 'ease-in-out',
+      fadeIn: 'fadeIn 0.8s ease-in-out',
+      slideUp: 'slideUp 0.8s ease-in-out'
+    },
+    styles: {
+      borderRadius: '0.5rem',
+      shadow: '0 10px 30px rgba(0, 0, 0, 0.5)',
+      gradient: 'linear-gradient(180deg, rgba(59, 130, 246, 0.1), transparent)'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Minimal Template - Helvetica + Sharp Edges
+  // ════════════════════════════════════════════════════════════════════════════
+  minimal: {
+    id: 'minimal',
+    name: 'Minimal',
+    description: 'Ultra-clean minimalist design',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Helvetica Neue', 'Arial', sans-serif",
+      code: "'SF Mono', 'Monaco', monospace"
+    },
+    animations: {
+      duration: 0.4,
+      easing: 'linear',
+      fadeIn: 'fadeIn 0.4s linear',
+      slideUp: 'slideUp 0.4s linear'
+    },
+    styles: {
+      borderRadius: '0',
+      shadow: 'none',
+      gradient: 'none'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Mono Template - Monospace Font + Terminal Style
+  // ════════════════════════════════════════════════════════════════════════════
+  mono: {
+    id: 'mono',
+    name: 'Mono',
+    description: 'Monospace terminal-inspired style',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Roboto Mono', 'Consolas', monospace",
+      code: "'Fira Code', 'Courier New', monospace"
+    },
+    animations: {
+      duration: 0.3,
+      easing: 'ease-out',
+      fadeIn: 'fadeIn 0.3s ease-out',
+      slideUp: 'slideUp 0.3s ease-out'
+    },
+    styles: {
+      borderRadius: '0',
+      shadow: '0 0 20px rgba(0, 255, 0, 0.3)',
+      gradient: 'radial-gradient(circle, rgba(0, 255, 0, 0.1), transparent)'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Rounded Template - Poppins Font + Maximum Roundness
+  // ════════════════════════════════════════════════════════════════════════════
+  rounded: {
+    id: 'rounded',
+    name: 'Rounded',
+    description: 'Soft and friendly with rounded corners',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Poppins', 'Nunito', sans-serif",
+      code: "'JetBrains Mono', monospace"
+    },
+    animations: {
+      duration: 0.7,
+      easing: 'cubic-bezier(0.68, -0.55, 0.265, 1.55)',
+      fadeIn: 'fadeIn 0.7s cubic-bezier(0.68, -0.55, 0.265, 1.55)',
+      slideUp: 'slideUp 0.7s cubic-bezier(0.68, -0.55, 0.265, 1.55)'
+    },
+    styles: {
+      borderRadius: '0.25rem',
+      shadow: '0 4px 8px rgba(96, 165, 250, 0.15)',
+      gradient: 'none'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Rounded Template - Poppins Font + Maximum Roundness
+  // ════════════════════════════════════════════════════════════════════════════
+  rounded: {
+    id: 'rounded',
+    name: 'Rounded',
+    description: 'Soft and friendly with rounded corners',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Poppins', 'Nunito', sans-serif",
+      code: "'JetBrains Mono', monospace"
+    },
+    animations: {
+      duration: 0.65,
+      easing: 'cubic-bezier(0.34, 1.56, 0.64, 1)',
+      fadeIn: 'fadeIn 0.65s cubic-bezier(0.34, 1.56, 0.64, 1)',
+      slideUp: 'slideUp 0.65s cubic-bezier(0.34, 1.56, 0.64, 1)'
+    },
+    styles: {
+      borderRadius: '2.5rem',
+      shadow: '0 25px 50px rgba(96, 165, 250, 0.3)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.2), rgba(168, 85, 247, 0.2))'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Space Template - Space Grotesk Font + Futuristic
+  // ════════════════════════════════════════════════════════════════════════════
+  space: {
+    id: 'space',
+    name: 'Space',
+    description: 'Futuristic space-themed design',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Space Grotesk', 'Orbitron', sans-serif",
+      code: "'Space Mono', monospace"
+    },
+    animations: {
+      duration: 0.55,
+      easing: 'cubic-bezier(0.19, 1, 0.22, 1)',
+      fadeIn: 'fadeIn 0.55s cubic-bezier(0.19, 1, 0.22, 1)',
+      slideUp: 'slideUp 0.55s cubic-bezier(0.19, 1, 0.22, 1)'
+    },
+    styles: {
+      borderRadius: '0.75rem',
+      shadow: '0 0 20px rgba(96, 165, 250, 0.4), 0 0 40px rgba(168, 85, 247, 0.2)',
+      gradient: 'radial-gradient(circle, rgba(96, 165, 250, 0.15), transparent)'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Code Template - Developer-Friendly Monospace
+  // ════════════════════════════════════════════════════════════════════════════
+  code: {
+    id: 'code',
+    name: 'Code',
+    description: 'Developer-friendly monospace design',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Fira Code', 'Cascadia Code', monospace",
+      code: "'JetBrains Mono', 'Source Code Pro', monospace"
+    },
+    animations: {
+      duration: 0.38,
+      easing: 'cubic-bezier(0, 0, 0.2, 1)',
+      fadeIn: 'fadeIn 0.38s cubic-bezier(0, 0, 0.2, 1)',
+      slideUp: 'slideUp 0.38s cubic-bezier(0, 0, 0.2, 1)'
+    },
+    styles: {
+      borderRadius: '0.5rem',
+      shadow: '0 8px 24px rgba(96, 165, 250, 0.15)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.1), rgba(168, 85, 247, 0.1))'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Tech Template - Ubuntu Font + Clean Tech Style
+  // ════════════════════════════════════════════════════════════════════════════
+  tech: {
+    id: 'tech',
+    name: 'Tech',
+    description: 'Clean technical presentation style',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Ubuntu', 'Roboto', sans-serif",
+      code: "'Ubuntu Mono', 'Inconsolata', monospace"
+    },
+    animations: {
+      duration: 0.48,
+      easing: 'cubic-bezier(0.25, 0.1, 0.25, 1)',
+      fadeIn: 'fadeIn 0.48s cubic-bezier(0.25, 0.1, 0.25, 1)',
+      slideUp: 'slideUp 0.48s cubic-bezier(0.25, 0.1, 0.25, 1)'
+    },
+    styles: {
+      borderRadius: '0.5rem',
+      shadow: '0 8px 24px rgba(96, 165, 250, 0.15)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.1), rgba(168, 85, 247, 0.1))'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Tech Template - Ubuntu Font + Clean Tech Style
+  // ════════════════════════════════════════════════════════════════════════════
+  tech: {
+    id: 'tech',
+    name: 'Tech',
+    description: 'Clean technical presentation style',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Ubuntu', 'Roboto', sans-serif",
+      code: "'Ubuntu Mono', 'Inconsolata', monospace"
+    },
+    animations: {
+      duration: 0.72,
+      easing: 'cubic-bezier(0.16, 1, 0.3, 1)',
+      fadeIn: 'fadeIn 0.72s cubic-bezier(0.16, 1, 0.3, 1)',
+      slideUp: 'slideUp 0.72s cubic-bezier(0.16, 1, 0.3, 1)'
+    },
+    styles: {
+      borderRadius: '1rem',
+      shadow: '0 20px 40px rgba(96, 165, 250, 0.3)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.2), rgba(168, 85, 247, 0.2))'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Corporate Template - Professional Business Style
+  // ════════════════════════════════════════════════════════════════════════════
+  corporate: {
+    id: 'corporate',
+    name: 'Corporate',
+    description: 'Professional business presentation',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Lato', 'Open Sans', sans-serif",
+      code: "'Consolas', monospace"
+    },
+    animations: {
+      duration: 0.52,
+      easing: 'cubic-bezier(0.45, 0, 0.55, 1)',
+      fadeIn: 'fadeIn 0.52s cubic-bezier(0.45, 0, 0.55, 1)',
+      slideUp: 'slideUp 0.52s cubic-bezier(0.45, 0, 0.55, 1)'
+    },
+    styles: {
+      borderRadius: '0.5rem',
+      shadow: '0 6px 20px rgba(96, 165, 250, 0.2)',
+      gradient: 'linear-gradient(180deg, rgba(96, 165, 250, 0.1), transparent)'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Display Template - Display Fonts + High Impact
+  // ════════════════════════════════════════════════════════════════════════════
+  display: {
+    id: 'display',
+    name: 'Display',
+    description: 'Bold display fonts for maximum impact',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Montserrat', 'Oswald', sans-serif",
+      code: "'Inconsolata', monospace"
+    },
+    animations: {
+      duration: 0.72,
+      easing: 'cubic-bezier(0.16, 1, 0.3, 1)',
+      fadeIn: 'fadeIn 0.72s cubic-bezier(0.16, 1, 0.3, 1)',
+      slideUp: 'slideUp 0.72s cubic-bezier(0.16, 1, 0.3, 1)'
+    },
+    styles: {
+      borderRadius: '1rem',
+      shadow: '0 20px 40px rgba(96, 165, 250, 0.3)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.2), rgba(168, 85, 247, 0.2))'
+    }
+  },
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Corporate Template - Professional Business Style
+  // ════════════════════════════════════════════════════════════════════════════
+  corporate: {
+    id: 'corporate',
+    name: 'Corporate',
+    description: 'Professional business presentation',
+    colors: { ...SHARED_COLORS },
+    fonts: {
+      primary: "'Lato', 'Open Sans', sans-serif",
+      code: "'Consolas', monospace"
+    },
+    animations: {
+      duration: 0.5,
+      easing: 'ease-in-out',
+      fadeIn: 'fadeIn 0.5s ease-in-out',
+      slideUp: 'slideUp 0.5s ease-in-out'
+    },
+    styles: {
+      borderRadius: '0.5rem',
+      shadow: '0 8px 20px rgba(96, 165, 250, 0.15)',
+      gradient: 'linear-gradient(135deg, rgba(96, 165, 250, 0.08), rgba(168, 85, 247, 0.08))'
+    }
+  }
+};
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Template Helper Functions
+// ══════════════════════════════════════════════════════════════════════════════
+
+export function getTemplate(templateId) {
+  return VIDEO_TEMPLATES[templateId] || VIDEO_TEMPLATES.modern;
+}
+
+export function getAllTemplates() {
+  return Object.values(VIDEO_TEMPLATES);
+}
+
+export function applyTemplate(templateId) {
+  const template = getTemplate(templateId);
+  const root = document.documentElement;
+
+  // Apply colors as CSS variables
+  Object.entries(template.colors).forEach(([key, value]) => {
+    root.style.setProperty(`--color-${key}`, value);
+  });
+
+  // Apply fonts
+  root.style.setProperty('--font-primary', template.fonts.primary);
+  root.style.setProperty('--font-code', template.fonts.code);
+
+  // Apply animation settings
+  root.style.setProperty('--anim-duration', `${template.animations.duration}s`);
+  root.style.setProperty('--anim-easing', template.animations.easing);
+
+  // Apply styles
+  root.style.setProperty('--border-radius', template.styles.borderRadius);
+  root.style.setProperty('--shadow', template.styles.shadow);
+  root.style.setProperty('--gradient', template.styles.gradient);
+
+  // Apply syntax highlighting colors (if available)
+  if (template.syntax) {
+    Object.entries(template.syntax).forEach(([key, value]) => {
+      root.style.setProperty(`--syntax-${key}`, value);
+    });
+  }
+
+  return template;
+}
+
+export function generateCSS(template) {
+  return `
+    :root {
+      --color-primary: ${template.colors.primary};
+      --color-secondary: ${template.colors.secondary};
+      --color-background: ${template.colors.background};
+      --color-surface: ${template.colors.surface};
+      --color-text: ${template.colors.text};
+      --color-text-secondary: ${template.colors.textSecondary};
+      --color-accent: ${template.colors.accent};
+      
+      --font-primary: ${template.fonts.primary};
+      --font-code: ${template.fonts.code};
+      
+      --anim-duration: ${template.animations.duration}s;
+      --anim-easing: ${template.animations.easing};
+      
+      --border-radius: ${template.styles.borderRadius};
+      --shadow: ${template.styles.shadow};
+      --gradient: ${template.styles.gradient};
+    }
+
+    body {
+      font-family: var(--font-primary);
+      background-color: var(--color-background);
+      color: var(--color-text);
+    }
+
+    .code-block {
+      font-family: var(--font-code);
+      background: var(--color-surface);
+      border-radius: var(--border-radius);
+      box-shadow: var(--shadow);
+    }
+
+    .gradient-backdrop {
+      background: var(--gradient);
+    }
+  `;
+}

src/renderer/js/video-renderer.js

@@ -0,0 +1,529 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Video Renderer
+// 100% Native Video Rendering Engine - No External Dependencies
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+export class VideoRenderer {
+  constructor(options = {}) {
+    this.options = {
+      width: options.width || 1920,
+      height: options.height || 1080,
+      fps: options.fps || 60,
+      format: options.format || 'webm',
+      quality: options.quality || 0.95,
+      videoBitsPerSecond: options.videoBitsPerSecond || 8000000, // 8 Mbps
+      ...options
+    };
+
+    this.mediaRecorder = null;
+    this.recordedChunks = [];
+    this.isRecording = false;
+  }
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // WebM/MP4 Recording using MediaRecorder API
+  // ════════════════════════════════════════════════════════════════════════════
+
+  async startRecording(element) {
+    if (this.isRecording) {
+      throw new Error('Recording already in progress');
+    }
+
+    try {
+      // Create a canvas to capture the element
+      this.canvas = document.createElement('canvas');
+      this.canvas.width = this.options.width;
+      this.canvas.height = this.options.height;
+      this.ctx = this.canvas.getContext('2d', { 
+        willReadFrequently: true,
+        alpha: false 
+      });
+
+      // Store element reference
+      this.element = element;
+
+      // Start capturing frames
+      this.startFrameCapture();
+
+      // Get stream from canvas
+      const stream = this.canvas.captureStream(this.options.fps);
+
+      // Determine MIME type
+      const mimeType = this.getBestMimeType();
+      console.log('[VideoRenderer] Recording with:', mimeType, 'at', this.options.fps, 'fps');
+
+      // Create MediaRecorder
+      this.mediaRecorder = new MediaRecorder(stream, {
+        mimeType,
+        videoBitsPerSecond: this.options.videoBitsPerSecond
+      });
+
+      this.recordedChunks = [];
+
+      // Handle data available
+      this.mediaRecorder.addEventListener('dataavailable', (event) => {
+        if (event.data && event.data.size > 0) {
+          this.recordedChunks.push(event.data);
+          console.log('[VideoRenderer] Chunk received:', event.data.size, 'bytes');
+        }
+      });
+
+      // Start recording
+      this.mediaRecorder.start(100); // Collect data every 100ms
+      this.isRecording = true;
+
+      console.log('[VideoRenderer] Recording started successfully');
+
+      return {
+        success: true,
+        message: 'Recording started'
+      };
+    } catch (error) {
+      console.error('[VideoRenderer] Error starting recording:', error);
+      throw error;
+    }
+  }
+
+  startFrameCapture() {
+    const captureFrame = () => {
+      if (!this.isRecording) {
+        return;
+      }
+
+      try {
+        // Clear canvas
+        this.ctx.fillStyle = '#000000';
+        this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
+
+        // Get element's computed styles
+        const styles = window.getComputedStyle(this.element);
+        
+        // Draw background
+        if (styles.backgroundColor && styles.backgroundColor !== 'rgba(0, 0, 0, 0)') {
+          this.ctx.fillStyle = styles.backgroundColor;
+          this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
+        }
+
+        // Render element content using DOM to canvas conversion
+        this.renderElementToCanvas(this.element, this.ctx);
+
+      } catch (error) {
+        console.error('[VideoRenderer] Frame capture error:', error);
+      }
+
+      if (this.isRecording) {
+        this._frameId = requestAnimationFrame(captureFrame);
+      }
+    };
+
+    captureFrame();
+  }
+
+  renderElementToCanvas(element, ctx) {
+    // Get all text nodes and render them
+    const walker = document.createTreeWalker(
+      element,
+      NodeFilter.SHOW_TEXT | NodeFilter.SHOW_ELEMENT,
+      null
+    );
+
+    const texts = [];
+    let node;
+    
+    while (node = walker.nextNode()) {
+      if (node.nodeType === Node.TEXT_NODE && node.textContent.trim()) {
+        const parent = node.parentElement;
+        if (parent && parent.offsetParent !== null) {
+          const rect = parent.getBoundingClientRect();
+          const elementRect = element.getBoundingClientRect();
+          const styles = window.getComputedStyle(parent);
+          
+          texts.push({
+            text: node.textContent,
+            x: rect.left - elementRect.left,
+            y: rect.top - elementRect.top,
+            width: rect.width,
+            height: rect.height,
+            font: styles.font || '16px sans-serif',
+            color: styles.color || '#ffffff',
+            fontSize: styles.fontSize,
+            fontFamily: styles.fontFamily,
+            fontWeight: styles.fontWeight,
+            textAlign: styles.textAlign || 'left',
+            lineHeight: parseFloat(styles.lineHeight) || parseFloat(styles.fontSize) * 1.2
+          });
+        }
+      }
+    }
+
+    // Scale factor
+    const scaleX = this.canvas.width / element.offsetWidth;
+    const scaleY = this.canvas.height / element.offsetHeight;
+
+    // Render texts
+    texts.forEach(item => {
+      ctx.save();
+      ctx.fillStyle = item.color;
+      ctx.font = `${item.fontWeight} ${parseFloat(item.fontSize) * scaleY}px ${item.fontFamily}`;
+      ctx.textAlign = item.textAlign;
+      ctx.textBaseline = 'top';
+      
+      const x = item.x * scaleX;
+      const y = item.y * scaleY + (parseFloat(item.fontSize) * scaleY);
+      
+      ctx.fillText(item.text, x, y);
+      ctx.restore();
+    });
+  }
+
+  async stopRecording() {
+    if (!this.isRecording || !this.mediaRecorder) {
+      throw new Error('No recording in progress');
+    }
+
+    return new Promise((resolve, reject) => {
+      this.mediaRecorder.addEventListener('stop', () => {
+        // Stop frame capture
+        if (this._frameId) {
+          cancelAnimationFrame(this._frameId);
+          this._frameId = null;
+        }
+
+        const blob = new Blob(this.recordedChunks, {
+          type: this.mediaRecorder.mimeType
+        });
+
+        this.isRecording = false;
+
+        console.log('[VideoRenderer] Recording stopped. Total size:', blob.size, 'bytes');
+        console.log('[VideoRenderer] Total chunks:', this.recordedChunks.length);
+
+        resolve({
+          success: true,
+          blob,
+          size: blob.size,
+          mimeType: this.mediaRecorder.mimeType,
+          url: URL.createObjectURL(blob)
+        });
+      });
+
+      this.mediaRecorder.addEventListener('error', (event) => {
+        this.isRecording = false;
+        if (this._frameId) {
+          cancelAnimationFrame(this._frameId);
+          this._frameId = null;
+        }
+        reject(new Error(`Recording error: ${event.error}`));
+      });
+
+      this.mediaRecorder.stop();
+    });
+  }
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // GIF Rendering using Canvas
+  // ════════════════════════════════════════════════════════════════════════════
+
+  async renderGIF(element, duration, fps = 15) {
+    const frames = [];
+    const interval = 1000 / fps;
+    const totalFrames = Math.ceil((duration / 1000) * fps);
+
+    // Create canvas for capturing
+    const canvas = document.createElement('canvas');
+    canvas.width = this.options.width;
+    canvas.height = this.options.height;
+    const ctx = canvas.getContext('2d');
+
+    // Capture frames
+    for (let i = 0; i < totalFrames; i++) {
+      await this.wait(interval);
+      
+      // Draw element to canvas
+      await this.drawElementToCanvas(element, canvas, ctx);
+
+      // Get image data
+      const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
+      frames.push({
+        data: this.quantizeColors(imageData.data, 256),
+        width: canvas.width,
+        height: canvas.height,
+        delay: Math.round(interval / 10) // Delay in 1/100s
+      });
+    }
+
+    // Encode GIF
+    const gifData = this.encodeGIF(frames);
+
+    return {
+      success: true,
+      frames: frames.length,
+      data: gifData,
+      blob: new Blob([gifData], { type: 'image/gif' })
+    };
+  }
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Helper Functions
+  // ════════════════════════════════════════════════════════════════════════════
+
+  getBestMimeType() {
+    // Chromium/Electron supports WebM very well, MP4 encoding is not directly supported
+    const types = [
+      'video/webm;codecs=vp9,opus',
+      'video/webm;codecs=vp9',
+      'video/webm;codecs=vp8,opus',
+      'video/webm;codecs=vp8',
+      'video/webm'
+    ];
+
+    for (const type of types) {
+      if (MediaRecorder.isTypeSupported(type)) {
+        console.log('[VideoRenderer] Using MIME type:', type);
+        return type;
+      }
+    }
+
+    console.warn('[VideoRenderer] No preferred MIME type supported, using default');
+    return 'video/webm';
+  }
+
+  async captureElementStream(element) {
+    const canvas = document.createElement('canvas');
+    canvas.width = this.options.width;
+    canvas.height = this.options.height;
+    const ctx = canvas.getContext('2d');
+
+    // Capture frames manually
+    const captureFrame = async () => {
+      await this.drawElementToCanvas(element, canvas, ctx);
+    };
+
+    const intervalId = setInterval(captureFrame, 1000 / this.options.fps);
+
+    // Store interval ID for cleanup
+    this._captureIntervalId = intervalId;
+
+    return canvas.captureStream(this.options.fps);
+  }
+
+  async drawElementToCanvas(element, canvas, ctx) {
+    // Use html2canvas-like approach
+    const rect = element.getBoundingClientRect();
+    
+    // Clear canvas
+    ctx.clearRect(0, 0, canvas.width, canvas.height);
+
+    // Draw background
+    ctx.fillStyle = window.getComputedStyle(element).backgroundColor || '#000';
+    ctx.fillRect(0, 0, canvas.width, canvas.height);
+
+    // For simplicity, we'll use drawImage if element is video/canvas
+    // For other elements, we'd need to serialize to SVG
+    if (element.tagName === 'CANVAS' || element.tagName === 'VIDEO') {
+      ctx.drawImage(element, 0, 0, canvas.width, canvas.height);
+    } else {
+      // Serialize element to data URL and draw
+      const data = await this.elementToDataURL(element);
+      const img = new Image();
+      await new Promise((resolve, reject) => {
+        img.onload = resolve;
+        img.onerror = reject;
+        img.src = data;
+      });
+      ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
+    }
+  }
+
+  async elementToDataURL(element) {
+    // Create SVG foreignObject
+    const rect = element.getBoundingClientRect();
+    const svg = `
+      <svg xmlns="http://www.w3.org/2000/svg" width="${rect.width}" height="${rect.height}">
+        <foreignObject width="100%" height="100%">
+          <div xmlns="http://www.w3.org/1999/xhtml">
+            ${element.outerHTML}
+          </div>
+        </foreignObject>
+      </svg>
+    `;
+
+    const blob = new Blob([svg], { type: 'image/svg+xml' });
+    return URL.createObjectURL(blob);
+  }
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // GIF Encoding (Simplified LZW Compression)
+  // ════════════════════════════════════════════════════════════════════════════
+
+  encodeGIF(frames) {
+    const { width, height } = frames[0];
+
+    // GIF Header
+    const header = this.stringToBytes('GIF89a');
+
+    // Logical Screen Descriptor
+    const lsd = new Uint8Array(7);
+    lsd[0] = width & 0xFF;
+    lsd[1] = (width >> 8) & 0xFF;
+    lsd[2] = height & 0xFF;
+    lsd[3] = (height >> 8) & 0xFF;
+    lsd[4] = 0xF7; // Global Color Table Flag
+    lsd[5] = 0x00; // Background Color Index
+    lsd[6] = 0x00; // Pixel Aspect Ratio
+
+    // Global Color Table (256 colors)
+    const gct = this.generateColorTable(256);
+
+    // Application Extension (for looping)
+    const appExt = new Uint8Array([
+      0x21, 0xFF, 0x0B,
+      ...this.stringToBytes('NETSCAPE2.0'),
+      0x03, 0x01, 0x00, 0x00, 0x00
+    ]);
+
+    const frameData = [];
+
+    for (const frame of frames) {
+      // Graphics Control Extension
+      const gce = new Uint8Array([
+        0x21, 0xF9, 0x04,
+        0x04, // Disposal method
+        frame.delay & 0xFF, (frame.delay >> 8) & 0xFF,
+        0x00, // Transparent color index
+        0x00
+      ]);
+
+      // Image Descriptor
+      const imgDesc = new Uint8Array(10);
+      imgDesc[0] = 0x2C; // Image separator
+      imgDesc[1] = 0x00; imgDesc[2] = 0x00; // Left
+      imgDesc[3] = 0x00; imgDesc[4] = 0x00; // Top
+      imgDesc[5] = width & 0xFF; imgDesc[6] = (width >> 8) & 0xFF;
+      imgDesc[7] = height & 0xFF; imgDesc[8] = (height >> 8) & 0xFF;
+      imgDesc[9] = 0x00; // Packed fields
+
+      // Image Data (simplified - use minimal compression)
+      const imageData = this.compressImageData(frame.data);
+
+      frameData.push(...gce, ...imgDesc, ...imageData);
+    }
+
+    // Trailer
+    const trailer = new Uint8Array([0x3B]);
+
+    // Combine all parts
+    return new Uint8Array([
+      ...header,
+      ...lsd,
+      ...gct,
+      ...appExt,
+      ...frameData,
+      ...trailer
+    ]);
+  }
+
+  generateColorTable(size) {
+    const table = new Uint8Array(size * 3);
+    for (let i = 0; i < size; i++) {
+      table[i * 3] = i;
+      table[i * 3 + 1] = i;
+      table[i * 3 + 2] = i;
+    }
+    return table;
+  }
+
+  quantizeColors(imageData, colorCount) {
+    // Simple color quantization
+    const quantized = new Uint8Array(imageData.length / 4);
+    for (let i = 0; i < imageData.length; i += 4) {
+      const r = imageData[i];
+      const g = imageData[i + 1];
+      const b = imageData[i + 2];
+      const gray = Math.floor(0.299 * r + 0.587 * g + 0.114 * b);
+      quantized[i / 4] = Math.floor(gray * (colorCount - 1) / 255);
+    }
+    return quantized;
+  }
+
+  compressImageData(data) {
+    // Minimal LZW compression (simplified)
+    const lzwMinCodeSize = 8;
+    const compressed = [lzwMinCodeSize];
+
+    // Simple run-length encoding as fallback
+    const blocks = [];
+    let currentBlock = [];
+
+    for (let i = 0; i < data.length; i++) {
+      currentBlock.push(data[i]);
+      if (currentBlock.length === 255) {
+        blocks.push(currentBlock.length, ...currentBlock);
+        currentBlock = [];
+      }
+    }
+
+    if (currentBlock.length > 0) {
+      blocks.push(currentBlock.length, ...currentBlock);
+    }
+
+    blocks.push(0); // Block terminator
+
+    return new Uint8Array([...compressed, ...blocks]);
+  }
+
+  stringToBytes(str) {
+    return new Uint8Array([...str].map(c => c.charCodeAt(0)));
+  }
+
+  wait(ms) {
+    return new Promise(resolve => setTimeout(resolve, ms));
+  }
+
+  // ════════════════════════════════════════════════════════════════════════════
+  // Cleanup
+  // ════════════════════════════════════════════════════════════════════════════
+
+  cleanup() {
+    if (this._captureIntervalId) {
+      clearInterval(this._captureIntervalId);
+      this._captureIntervalId = null;
+    }
+
+    if (this.mediaRecorder && this.isRecording) {
+      this.mediaRecorder.stop();
+    }
+
+    this.recordedChunks = [];
+    this.mediaRecorder = null;
+    this.isRecording = false;
+  }
+}
+
+// ══════════════════════════════════════════════════════════════════════════════
+// Export Format Helpers
+// ══════════════════════════════════════════════════════════════════════════════
+
+export function blobToBase64(blob) {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onloadend = () => resolve(reader.result);
+    reader.onerror = reject;
+    reader.readAsDataURL(blob);
+  });
+}
+
+export function downloadBlob(blob, filename) {
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  a.href = url;
+  a.download = filename;
+  document.body.appendChild(a);
+  a.click();
+  document.body.removeChild(a);
+  URL.revokeObjectURL(url);
+}

src/shared/README.md

@@ -0,0 +1,97 @@
+# Shared Modules
+
+This folder contains modules used by both main and renderer processes.
+
+## Files
+
+### security-core.js
+Enterprise-grade security system with comprehensive protection.
+
+## Features
+
+### 1. Input Validation
+- Path traversal detection
+- Malicious pattern checking
+- Length validation
+
+### 2. Path Safety
+- Forbidden directory protection (Windows, System, etc.)
+- Whitelist validation
+- Workspace folder support
+
+### 3. Symlink Protection
+- Symlink detection
+- Circular reference prevention
+- Depth limiting
+
+### 4. File Validation
+- Extension whitelist
+- Size limits (min/max)
+- Content verification
+
+### 5. Integrity Verification
+- SHA-256 hash calculation
+- File tampering detection
+- Cache management
+
+### 6. Rate Limiting
+- Operation throttling
+- Time-window based limits
+- Abuse prevention
+
+### 7. ReDoS Protection
+- Regex timeout enforcement
+- Pattern execution monitoring
+- Safe regex execution
+
+## Usage
+
+```javascript
+import { SecurityManager } from './security-core.js';
+
+const security = new SecurityManager({
+  MAX_FILE_SIZE: 10 * 1024 * 1024,
+  ALLOWED_EXTENSIONS: ['.js', '.ts', '.py'],
+  EXTRA_ALLOWED_DIRS: ['/path/to/allowed/dir']
+});
+
+// Validate and read file
+const result = await security.secureReadFile(filePath);
+
+// Get statistics
+const stats = security.getSecurityStats();
+
+// Export audit log
+const log = security.exportSecurityLog();
+```
+
+## Custom Error Classes
+
+- `SecurityError` - Base security error
+- `PathTraversalError` - Path attack detected
+- `SymlinkError` - Symlink violation
+- `FileValidationError` - File validation failed
+- `ReDoSError` - Regex timeout
+- `RateLimitError` - Rate limit exceeded
+
+## Configuration
+
+All security settings are configurable:
+
+```javascript
+const SECURITY_CONFIG = {
+  MAX_PATH_LENGTH: 260,
+  MAX_FILE_SIZE: 10 * 1024 * 1024,
+  ALLOWED_EXTENSIONS: [...],
+  FORBIDDEN_PATHS: [...],
+  MAX_OPERATIONS_PER_MINUTE: 500,
+  // ... more settings
+};
+```
+
+## Adding New Validations
+
+1. Create validation method in SecurityManager class
+2. Add to validateFile() pipeline
+3. Add custom error class if needed
+4. Update configuration

src/shared/content-fingerprint.js

@@ -0,0 +1,236 @@
+/**
+ * Content Fingerprinting System
+ * 
+ * สร้าง unique identifier สำหรับแต่ละบรรทัดเนื้อหา
+ * ใช้ในการจับคู่การตั้งค่า (position, edits) กับเนื้อหา
+ * แม้ว่าจะมีการเพิ่ม/ลบเนื้อหาอื่นในไฟล์
+ * 
+ * @author Chahua Development Co., Ltd.
+ * @version 2.1.0
+ */
+
+export class ContentFingerprint {
+    /**
+     * สร้าง fingerprint จากเนื้อหาและ metadata
+     * 
+     * @param {HTMLElement} element - Element ที่ต้องการสร้าง fingerprint
+     * @returns {string} - Unique fingerprint string
+     */
+    static generate(element) {
+        if (!element) return null;
+
+        const tag = element.tagName.toLowerCase();
+        const text = element.textContent.trim();
+        
+        // ใช้ 80 ตัวอักษรแรกเพื่อความแม่นยำสูง
+        const contentPreview = text.substring(0, 80);
+        
+        // สร้าง fingerprint จาก tag + content + length
+        const fingerprint = `${tag}:${contentPreview}:${text.length}`;
+        
+        // สร้าง hash แบบง่าย
+        return this.simpleHash(fingerprint);
+    }
+
+    /**
+     * สร้าง stable fingerprint ที่ไม่เปลี่ยนแปลงง่าย
+     * เหมาะสำหรับการเก็บ settings ระยะยาว
+     * 
+     * @param {HTMLElement} element 
+     * @returns {Object} - Fingerprint object with multiple identifiers
+     */
+    static generateStable(element) {
+        if (!element) return null;
+
+        const tag = element.tagName.toLowerCase();
+        const text = element.textContent.trim();
+        
+        // Primary: hash ของ 80 ตัวแรก
+        const primary = this.generate(element);
+        
+        // Secondary: hash ของ 30 ตัวแรก (partial match)
+        const partialText = text.substring(0, 30);
+        const secondary = this.simpleHash(`${tag}:${partialText}`);
+        
+        // Tertiary: hash จาก pattern (ใช้ได้กับข้อความที่มี structure คล้ายกัน)
+        const pattern = this.extractPattern(text);
+        const tertiary = this.simpleHash(`${tag}:${pattern}`);
+
+        return {
+            primary,      // ความแม่นยำสูงสุด
+            secondary,    // ทนต่อการแก้ไขเล็กน้อย
+            tertiary,     // ทนต่อการเปลี่ยนแปลงมาก
+            tag,
+            length: text.length,
+            preview: text.substring(0, 50)
+        };
+    }
+
+    /**
+     * Extract pattern จากข้อความ
+     * เช่น "Item 1" -> "Item #"
+     * 
+     * @param {string} text 
+     * @returns {string}
+     */
+    static extractPattern(text) {
+        return text
+            .replace(/\d+/g, '#')           // เลข -> #
+            .replace(/[a-zA-Z]{4,}/g, 'W')  // คำยาว -> W
+            .substring(0, 40);              // เอาแค่ 40 ตัวแรก
+    }
+
+    /**
+     * Simple hash function (DJB2 algorithm)
+     * 
+     * @param {string} str 
+     * @returns {string} - Hex hash string
+     */
+    static simpleHash(str) {
+        let hash = 5381;
+        for (let i = 0; i < str.length; i++) {
+            hash = ((hash << 5) + hash) + str.charCodeAt(i);
+            hash = hash & hash; // Convert to 32bit integer
+        }
+        return Math.abs(hash).toString(36); // Base36 สั้นกว่า hex
+    }
+
+    /**
+     * จับคู่ fingerprint กับ settings ที่บันทึกไว้
+     * รองรับการ match แบบ fuzzy
+     * 
+     * @param {Object} stableFingerprint - จาก generateStable()
+     * @param {Array} savedSettings - Array of saved setting objects
+     * @returns {Object|null} - Matched setting หรือ null
+     */
+    static match(stableFingerprint, savedSettings) {
+        if (!stableFingerprint || !savedSettings || !savedSettings.length) {
+            return null;
+        }
+
+        // 1. ลอง match primary (exact match)
+        let matched = savedSettings.find(s => 
+            s.fingerprint?.primary === stableFingerprint.primary
+        );
+        if (matched) {
+            matched.matchConfidence = 'exact';
+            return matched;
+        }
+
+        // 2. ลอง match secondary (partial match)
+        matched = savedSettings.find(s => 
+            s.fingerprint?.secondary === stableFingerprint.secondary &&
+            s.fingerprint?.tag === stableFingerprint.tag
+        );
+        if (matched) {
+            matched.matchConfidence = 'high';
+            return matched;
+        }
+
+        // 3. ลอง match tertiary (pattern match)
+        matched = savedSettings.find(s => 
+            s.fingerprint?.tertiary === stableFingerprint.tertiary &&
+            s.fingerprint?.tag === stableFingerprint.tag
+        );
+        if (matched) {
+            matched.matchConfidence = 'medium';
+            return matched;
+        }
+
+        // 4. ลอง match โดยดูจาก tag + length (คล้ายกัน)
+        matched = savedSettings.find(s => 
+            s.fingerprint?.tag === stableFingerprint.tag &&
+            Math.abs(s.fingerprint?.length - stableFingerprint.length) < 10
+        );
+        if (matched) {
+            matched.matchConfidence = 'low';
+            return matched;
+        }
+
+        return null;
+    }
+
+    /**
+     * สร้าง fingerprint สำหรับทั้ง slide
+     * ใช้ detect ว่ามีการเปลี่ยนแปลงเนื้อหาหรือไม่
+     * 
+     * @param {HTMLElement} sceneElement 
+     * @returns {string}
+     */
+    static generateSlideFingerprint(sceneElement) {
+        if (!sceneElement) return null;
+
+        const elements = sceneElement.querySelectorAll('h1, h2, h3, h4, h5, h6, p, li, blockquote');
+        const fingerprints = Array.from(elements).map(el => this.generate(el));
+        
+        return this.simpleHash(fingerprints.join('|'));
+    }
+
+    /**
+     * เปรียบเทียบว่า slide เปลี่ยนแปลงหรือไม่
+     * 
+     * @param {string} oldFingerprint 
+     * @param {string} newFingerprint 
+     * @returns {boolean}
+     */
+    static hasSlideChanged(oldFingerprint, newFingerprint) {
+        return oldFingerprint !== newFingerprint;
+    }
+
+    /**
+     * สร้าง element mapping สำหรับทั้ง slide
+     * เพื่อใช้ในการ apply settings
+     * 
+     * @param {HTMLElement} sceneElement 
+     * @returns {Array} - Array of {element, fingerprint, index}
+     */
+    static mapSlideElements(sceneElement) {
+        if (!sceneElement) return [];
+
+        const elements = sceneElement.querySelectorAll('h1, h2, h3, h4, h5, h6, p, li, blockquote');
+        
+        return Array.from(elements).map((element, index) => ({
+            element,
+            fingerprint: this.generateStable(element),
+            index,
+            tag: element.tagName.toLowerCase()
+        }));
+    }
+
+    /**
+     * Validate fingerprint object
+     * 
+     * @param {Object} fingerprint 
+     * @returns {boolean}
+     */
+    static isValid(fingerprint) {
+        return fingerprint &&
+               fingerprint.primary &&
+               fingerprint.secondary &&
+               fingerprint.tertiary &&
+               fingerprint.tag;
+    }
+
+    /**
+     * สร้าง debug info สำหรับ fingerprint
+     * 
+     * @param {Object} fingerprint 
+     * @returns {string}
+     */
+    static debug(fingerprint) {
+        if (!fingerprint) return 'null';
+        
+        return `
+Fingerprint Debug:
+- Primary: ${fingerprint.primary}
+- Secondary: ${fingerprint.secondary}
+- Tertiary: ${fingerprint.tertiary}
+- Tag: ${fingerprint.tag}
+- Length: ${fingerprint.length}
+- Preview: "${fingerprint.preview}"
+        `.trim();
+    }
+}
+
+// Export เป็น named export
+export default ContentFingerprint;

src/shared/layout-schema.js

@@ -0,0 +1,363 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Markdown Presenter - Layout Schema & Tree Builder
+// Converts parsed markdown slides into structured presentation layout blocks
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 1.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+const LayoutNodeKind = {
+    SLIDE: 'slide',
+    SECTION: 'section',
+    HEADING: 'heading',
+    TEXT: 'text',
+    LIST: 'list',
+    CODE: 'code',
+    TABLE: 'table',
+    CALLOUT: 'callout',
+    IMAGE: 'image',
+    DIVIDER: 'divider',
+    HTML: 'html',
+    LINK: 'link'
+};
+
+const ListKind = {
+    UNORDERED: 'unordered',
+    ORDERED: 'ordered',
+    TASK: 'task'
+};
+
+let layoutIdCounter = 0;
+function nextLayoutId(prefix) {
+    layoutIdCounter += 1;
+    return `${prefix}-${layoutIdCounter}`;
+}
+
+const HEADING_LINE_WEIGHTS = {
+    1: 3.2,
+    2: 2.6,
+    3: 2,
+    4: 1.6,
+    5: 1.4,
+    6: 1.2
+};
+
+function estimateTextLines(text) {
+    if (!text) return 1;
+    const words = text.trim().split(/\s+/).length;
+    return Math.max(1, Math.ceil(words / 12));
+}
+
+function estimateListLines(items) {
+    if (!items || items.length === 0) return 0;
+    return items.reduce((sum, item) => sum + Math.max(1.1, estimateTextLines(item.text) * 0.85), 0);
+}
+
+function estimateBlockLines(block) {
+    switch (block.kind) {
+        case LayoutNodeKind.HEADING:
+            return HEADING_LINE_WEIGHTS[block.level] || 2.4;
+        case LayoutNodeKind.TEXT:
+            return estimateTextLines(block.text);
+        case LayoutNodeKind.LIST:
+            return estimateListLines(block.items) + 0.5;
+        case LayoutNodeKind.CODE: {
+            const lines = block.content.split('\n').length;
+            return Math.min(12, lines + 1.5);
+        }
+        case LayoutNodeKind.TABLE: {
+            const rows = block.rows ? block.rows.length : 0;
+            return 2.5 + rows * 0.8;
+        }
+        case LayoutNodeKind.CALLOUT:
+            return Math.max(2, estimateTextLines(block.text) * 1.2);
+        case LayoutNodeKind.IMAGE:
+            return 4.5;
+        case LayoutNodeKind.DIVIDER:
+            return 0.5;
+        case LayoutNodeKind.HTML:
+            return 3;
+        case LayoutNodeKind.LINK:
+            return Math.max(1, estimateTextLines(block.text));
+        default:
+            return 1;
+    }
+}
+
+function createHeadingBlock(level, text, html = null) {
+    const normalizedLevel = Math.min(Math.max(level || 1, 1), 6);
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.HEADING,
+        level: normalizedLevel,
+        text: text || '',
+        html: html || null
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createSectionFromHeading(headingItem, fallbackTitle, fallbackLevel = 2) {
+    const level = headingItem ? parseInt(headingItem.type.replace('h', ''), 10) || fallbackLevel : fallbackLevel;
+    const title = headingItem ? headingItem.content : fallbackTitle;
+
+    const section = {
+        id: nextLayoutId('section'),
+        kind: LayoutNodeKind.SECTION,
+        level,
+        title: title || fallbackTitle || '',
+        heading: headingItem || null,
+        blocks: [],
+        metrics: {
+            estimatedLines: 0
+        }
+    };
+
+    const headingText = title || fallbackTitle || '';
+    if (headingText) {
+        const headingBlock = createHeadingBlock(level, headingText, headingItem?.html || null);
+        section.blocks.push(headingBlock);
+        section.metrics.estimatedLines += headingBlock.metrics.estimatedLines;
+    }
+
+    return section;
+}
+
+function createTextBlock(text, html = null) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.TEXT,
+        text,
+        html: html || null
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createListBlock(listType) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.LIST,
+        listType,
+        items: []
+    };
+    block.metrics = { estimatedLines: 0 };
+    return block;
+}
+
+function createCodeBlock(item) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.CODE,
+        language: item.language || 'text',
+        content: item.content
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createTableBlock(item) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.TABLE,
+        rows: item.rows || []
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createCalloutBlock(item) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.CALLOUT,
+        text: item.content,
+        level: item.level || 1,
+        html: item.html || null
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createImageBlock(item) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.IMAGE,
+        src: item.src,
+        alt: item.alt || '',
+        title: item.title || ''
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createDividerBlock() {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.DIVIDER
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createHtmlBlock(item) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.HTML,
+        html: item.html || item.content
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function createLinkBlock(item) {
+    const block = {
+        id: nextLayoutId('block'),
+        kind: LayoutNodeKind.LINK,
+        text: item.text || item.content || '',
+        href: item.url || item.href || '',
+        title: item.title || '',
+        html: item.html || null
+    };
+    block.metrics = { estimatedLines: estimateBlockLines(block) };
+    return block;
+}
+
+function appendBlockToSection(section, block) {
+    section.blocks.push(block);
+    section.metrics.estimatedLines += block.metrics.estimatedLines;
+}
+
+function appendListItem(block, item) {
+    block.items.push({
+        id: nextLayoutId('listitem'),
+        text: item.content,
+        marker: item.marker || null,
+        number: item.number || null,
+        checked: !!item.checked,
+        html: item.html || null
+    });
+    block.metrics.estimatedLines = estimateBlockLines(block);
+}
+
+function resolveListType(itemType) {
+    if (itemType === 'numbered-item') return ListKind.ORDERED;
+    if (itemType === 'task-list') return ListKind.TASK;
+    return ListKind.UNORDERED;
+}
+
+function addItemToSection(section, item) {
+    switch (item.type) {
+        case 'text': {
+            const lastBlock = section.blocks[section.blocks.length - 1];
+            if (lastBlock && lastBlock.kind === LayoutNodeKind.TEXT) {
+                const previousLines = lastBlock.metrics.estimatedLines;
+                lastBlock.text = `${lastBlock.text}\n\n${item.content}`;
+                if (item.html) {
+                    const joiner = lastBlock.html ? '<br><br>' : '';
+                    lastBlock.html = lastBlock.html ? `${lastBlock.html}${joiner}${item.html}` : item.html;
+                }
+                lastBlock.metrics.estimatedLines = estimateBlockLines(lastBlock);
+                section.metrics.estimatedLines += (lastBlock.metrics.estimatedLines - previousLines);
+            } else {
+                appendBlockToSection(section, createTextBlock(item.content, item.html || null));
+            }
+            break;
+        }
+        case 'list-item':
+        case 'numbered-item':
+        case 'task-list': {
+            const listType = resolveListType(item.type);
+            let listBlock = section.blocks[section.blocks.length - 1];
+            if (!listBlock || listBlock.kind !== LayoutNodeKind.LIST || listBlock.listType !== listType) {
+                listBlock = createListBlock(listType);
+                appendBlockToSection(section, listBlock);
+            }
+            const previousLines = listBlock.metrics.estimatedLines;
+            appendListItem(listBlock, item);
+            section.metrics.estimatedLines += (listBlock.metrics.estimatedLines - previousLines);
+            break;
+        }
+        case 'code':
+            appendBlockToSection(section, createCodeBlock(item));
+            break;
+        case 'table':
+            appendBlockToSection(section, createTableBlock(item));
+            break;
+        case 'blockquote':
+            appendBlockToSection(section, createCalloutBlock(item));
+            break;
+        case 'image':
+            appendBlockToSection(section, createImageBlock(item));
+            break;
+        case 'hr':
+            appendBlockToSection(section, createDividerBlock());
+            break;
+        case 'html':
+            appendBlockToSection(section, createHtmlBlock(item));
+            break;
+        case 'link':
+            appendBlockToSection(section, createLinkBlock(item));
+            break;
+        default:
+            appendBlockToSection(section, createTextBlock(item.content || '', item.html || null));
+            break;
+    }
+}
+
+export function buildLayoutTreeForSlide(slide) {
+    const root = {
+        id: nextLayoutId('slide'),
+        kind: LayoutNodeKind.SLIDE,
+        title: slide.title || '',
+        subtitle: slide.subtitle || '',
+        sections: [],
+        metrics: {
+            estimatedLines: 0
+        }
+    };
+
+    let currentSection = null;
+
+    const ensureSection = (headingItem = null) => {
+        if (headingItem) {
+            currentSection = createSectionFromHeading(headingItem, slide.title);
+            root.sections.push(currentSection);
+        } else if (!currentSection) {
+            currentSection = createSectionFromHeading(null, slide.title || '');
+            root.sections.push(currentSection);
+        }
+        return currentSection;
+    };
+
+    const contentItems = Array.isArray(slide.content) ? slide.content : [];
+    for (const item of contentItems) {
+        if (item.type && /^h[1-6]$/.test(item.type)) {
+            ensureSection(item);
+            continue;
+        }
+
+        ensureSection();
+        addItemToSection(currentSection, item);
+    }
+
+    if (root.sections.length === 0) {
+        currentSection = createSectionFromHeading(null, slide.title || 'Overview');
+        root.sections.push(currentSection);
+        if (contentItems.length === 0 && slide.subtitle) {
+            appendBlockToSection(currentSection, createTextBlock(slide.subtitle));
+        }
+    }
+
+    root.metrics.estimatedLines = root.sections.reduce((sum, section) => {
+        return sum + (section.metrics?.estimatedLines || 0);
+    }, 0);
+
+    return root;
+}
+
+export { 
+    LayoutNodeKind, 
+    ListKind, 
+    estimateBlockLines 
+};

src/shared/markdown-parser.js

@@ -0,0 +1,512 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Markdown Presenter - Markdown Parser
+// Parse Markdown into Presentation Slides
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Version: 2.0.0
+// License: MIT
+// ══════════════════════════════════════════════════════════════════════════════
+
+import { MarkdownSyntax, detectBlockType, parseInline } from './markdown-syntax.js';
+import { applyPagination, getPaginationInfo } from './slide-paginator.js';
+
+export class MarkdownParser {
+  constructor(options = {}) {
+    this.options = {
+      slideBreak: options.slideBreak || '---', // Horizontal rule for slide breaks
+      h1AsSlide: options.h1AsSlide !== false, // # creates new slide
+      h2AsSlide: options.h2AsSlide || false,  // ## creates new slide
+      enablePagination: options.enablePagination !== false, // Auto-split long slides
+      maxLinesPerSlide: options.maxLinesPerSlide || 8, // Max visual lines per slide
+      ...options
+    };
+  }
+
+  /**
+   * Parse markdown text into slides
+   * @param {string} markdown - Raw markdown text
+   * @returns {Array} Array of slide objects
+   */
+  parse(markdown) {
+    if (!markdown || typeof markdown !== 'string') {
+      throw new Error('Invalid markdown input');
+    }
+
+    // Split by slide breaks (---)
+    const rawSlides = this.splitIntoSlides(markdown);
+    
+    // Parse each slide
+    const slides = rawSlides.map((slideText, index) => {
+      return this.parseSlide(slideText, index);
+    });
+
+    // Filter empty slides
+    const nonEmptySlides = slides.filter(slide => slide.content.length > 0);
+    
+    // Apply pagination if enabled
+    if (this.options.enablePagination) {
+      const paginatedSlides = [];
+      let globalIndex = 0;
+      
+      for (const slide of nonEmptySlides) {
+        const pages = applyPagination(slide);
+        
+        // Update indices
+        pages.forEach((page, pageIndex) => {
+          page.index = globalIndex++;
+          page.originalIndex = slide.index;
+          paginatedSlides.push(page);
+        });
+      }
+      
+      return paginatedSlides;
+    }
+    
+    return nonEmptySlides;
+  }
+
+  /**
+   * Split markdown into slides based on rules
+   */
+  splitIntoSlides(markdown) {
+    const slides = [];
+    let currentSlide = [];
+    const lines = markdown.split('\n');
+    
+    // Skip frontmatter block if present
+    let startIndex = 0;
+    if (lines[0] && lines[0].trim() === '---') {
+      // Find closing ---
+      for (let i = 1; i < Math.min(lines.length, 50); i++) {
+        if (lines[i].trim() === '---') {
+          startIndex = i + 1;
+          break;
+        }
+      }
+    }
+
+    for (let i = startIndex; i < lines.length; i++) {
+      const line = lines[i];
+      const trimmed = line.trim();
+
+      // Check for slide break (---)
+      if (trimmed === '---' || trimmed === '___' || trimmed === '***') {
+        if (currentSlide.length > 0) {
+          slides.push(currentSlide.join('\n'));
+          currentSlide = [];
+        }
+        continue;
+      }
+
+      // Check for H1 as slide break
+      if (this.options.h1AsSlide && trimmed.startsWith('# ') && currentSlide.length > 0) {
+        slides.push(currentSlide.join('\n'));
+        currentSlide = [line];
+        continue;
+      }
+
+      // Check for H2 as slide break
+      if (this.options.h2AsSlide && trimmed.startsWith('## ') && currentSlide.length > 0) {
+        slides.push(currentSlide.join('\n'));
+        currentSlide = [line];
+        continue;
+      }
+
+      currentSlide.push(line);
+    }
+
+    // Add last slide
+    if (currentSlide.length > 0) {
+      slides.push(currentSlide.join('\n'));
+    }
+
+    return slides;
+  }
+
+  /**
+   * Parse individual slide content using Markdown Dictionary
+   */
+  parseSlide(slideText, index) {
+    const content = [];
+    const lines = slideText.split('\n');
+    
+    let title = '';
+    let subtitle = '';
+    let customDuration = null;
+    let inCodeBlock = false;
+    let codeLines = [];
+    let codeLang = '';
+    let codeFence = '```';
+    let inBlockquote = false;
+    let blockquoteLines = [];
+    let inTable = false;
+    let tableRows = [];
+    let inHtml = false;
+    let htmlLines = [];
+
+    for (let i = 0; i < lines.length; i++) {
+      const line = lines[i];
+      const trimmed = line.trim();
+      const nextLine = i < lines.length - 1 ? lines[i + 1] : null;
+
+      // Skip empty lines (unless in special block)
+      if (!trimmed && !inCodeBlock && !inHtml) {
+        // End blockquote on empty line
+        if (inBlockquote && blockquoteLines.length > 0) {
+          const quoteText = blockquoteLines.join('\n');
+          content.push({
+            type: 'blockquote',
+            content: quoteText,
+            html: this.parseInline(quoteText)
+          });
+          blockquoteLines = [];
+          inBlockquote = false;
+        }
+        // End table on empty line
+        if (inTable && tableRows.length > 0) {
+          content.push({
+            type: 'table',
+            rows: tableRows
+          });
+          tableRows = [];
+          inTable = false;
+        }
+        continue;
+      }
+
+      // Check for metadata (subtitle: or duration:)
+      if (trimmed.match(/^(subtitle|duration):\s*(.+)$/i)) {
+        const match = trimmed.match(/^(subtitle|duration):\s*(.+)$/i);
+        const key = match[1].toLowerCase();
+        const value = match[2].trim();
+        
+        if (key === 'subtitle') {
+          subtitle = value;
+        } else if (key === 'duration') {
+          customDuration = parseFloat(value);
+        }
+        continue;
+      }
+
+      // Code block detection (using dictionary)
+      const codeBlockCheck = MarkdownSyntax.blocks.codeBlock.detect(trimmed);
+      if (codeBlockCheck) {
+        if (codeBlockCheck.type === 'code-fence-start') {
+          if (!inCodeBlock) {
+            // Start code block
+            inCodeBlock = true;
+            codeLang = codeBlockCheck.language || 'text';
+            codeFence = codeBlockCheck.fence || '```';
+            codeLines = [];
+          } else {
+            // End code block
+            inCodeBlock = false;
+            content.push({
+              type: 'code',
+              language: codeLang,
+              content: codeLines.join('\n')
+            });
+            codeLines = [];
+            codeLang = '';
+            codeFence = '```';
+          }
+          continue;
+        } else if (codeBlockCheck.type === 'code-indented' && !inCodeBlock) {
+          // Indented code (4 spaces or tab)
+          content.push({
+            type: 'code',
+            language: 'text',
+            content: codeBlockCheck.content
+          });
+          continue;
+        }
+      }
+
+      if (inCodeBlock) {
+        codeLines.push(line);
+        continue;
+      }
+
+      // HTML block detection
+      const htmlCheck = MarkdownSyntax.blocks.html.detect(trimmed);
+      if (htmlCheck) {
+        if (!inHtml) {
+          inHtml = true;
+          htmlLines = [line];
+        } else {
+          htmlLines.push(line);
+        }
+        
+        // Check if HTML block ends (closing tag)
+        if (trimmed.match(/<\/[a-z][a-z0-9-]*\s*>/i) || trimmed === '-->') {
+          inHtml = false;
+          content.push({
+            type: 'html',
+            content: htmlLines.join('\n')
+          });
+          htmlLines = [];
+        }
+        continue;
+      }
+
+      if (inHtml) {
+        htmlLines.push(line);
+        continue;
+      }
+
+      // Heading detection (using dictionary - supports both ATX and Setext)
+      const headingCheck = MarkdownSyntax.blocks.heading.detect(trimmed, nextLine?.trim());
+      if (headingCheck) {
+        const text = headingCheck.content;
+        const level = headingCheck.level;
+        
+        const headingHtml = this.parseInline(text);
+
+        if (level === 1) {
+          if (!title) title = text;
+          content.push({ type: 'h1', content: text, html: headingHtml });
+        } else if (level === 2) {
+          if (!subtitle && title) subtitle = text;
+          content.push({ type: 'h2', content: text, html: headingHtml });
+        } else if (level === 3) {
+          content.push({ type: 'h3', content: text, html: headingHtml });
+        } else if (level === 4) {
+          content.push({ type: 'h4', content: text, html: headingHtml });
+        } else if (level === 5) {
+          content.push({ type: 'h5', content: text, html: headingHtml });
+        } else if (level === 6) {
+          content.push({ type: 'h6', content: text, html: headingHtml });
+        }
+        
+        // Skip next line if Setext style
+        if (headingCheck.style === 'setext') {
+          i++;
+        }
+        continue;
+      }
+
+      // Horizontal rule detection
+      const hrCheck = MarkdownSyntax.blocks.hr.detect(trimmed);
+      if (hrCheck) {
+        content.push({ type: 'hr' });
+        continue;
+      }
+
+      // Task list detection (GFM)
+      const taskCheck = MarkdownSyntax.blocks.taskList.detect(trimmed);
+      if (taskCheck) {
+        content.push({
+          type: 'task-list',
+          checked: taskCheck.checked,
+          content: taskCheck.content,
+          html: this.parseInline(taskCheck.content)
+        });
+        continue;
+      }
+
+      // Table detection (GFM)
+      const tableCheck = MarkdownSyntax.blocks.table.detect(trimmed);
+      if (tableCheck) {
+        inTable = true;
+        if (tableCheck.type === 'table-row') {
+          tableRows.push(tableCheck.cells);
+        }
+        continue;
+      }
+
+      // List detection (using dictionary - supports -, *, +, and numbered)
+      const listCheck = MarkdownSyntax.blocks.list.detect(trimmed);
+      if (listCheck) {
+        if (listCheck.ordered) {
+          content.push({
+            type: 'numbered-item',
+            number: listCheck.number,
+            content: listCheck.content,
+            html: this.parseInline(listCheck.content)
+          });
+        } else {
+          content.push({
+            type: 'list-item',
+            marker: listCheck.marker,
+            content: listCheck.content,
+            html: this.parseInline(listCheck.content)
+          });
+        }
+        continue;
+      }
+
+      // Blockquote detection (using dictionary - supports nested >)
+      const blockquoteCheck = MarkdownSyntax.blocks.blockquote.detect(trimmed);
+      if (blockquoteCheck) {
+        inBlockquote = true;
+        blockquoteLines.push(blockquoteCheck.content);
+        continue;
+      }
+
+      // Image detection (inline pattern)
+      if (trimmed.match(MarkdownSyntax.inline.image.patterns[0].regex)) {
+        const match = trimmed.match(/!\[([^\]]*)\]\(([^)\s]+)(?:\s+"([^"]+)")?\)/);
+        content.push({
+          type: 'image',
+          alt: match[1] || '',
+          src: match[2],
+          title: match[3] || ''
+        });
+        continue;
+      }
+
+      // Link detection (inline pattern)
+      if (trimmed.match(MarkdownSyntax.inline.link.patterns[0].regex)) {
+        const match = trimmed.match(/\[([^\]]+)\]\(([^)\s]+)(?:\s+"([^"]+)")?\)/);
+        content.push({
+          type: 'link',
+          text: match[1],
+          url: match[2],
+          title: match[3] || '',
+          html: this.parseInline(match[0])
+        });
+        continue;
+      }
+
+      // Regular text/paragraph (with inline formatting)
+      if (trimmed) {
+        content.push({
+          type: 'text',
+          content: trimmed,
+          html: this.parseInline(trimmed)
+        });
+      }
+    }
+
+    // Flush remaining blocks
+    if (blockquoteLines.length > 0) {
+      const quoteText = blockquoteLines.join('\n');
+      content.push({
+        type: 'blockquote',
+        content: quoteText,
+        html: this.parseInline(quoteText)
+      });
+    }
+    if (tableRows.length > 0) {
+      content.push({
+        type: 'table',
+        rows: tableRows
+      });
+    }
+    if (htmlLines.length > 0) {
+      content.push({
+        type: 'html',
+        content: htmlLines.join('\n')
+      });
+    }
+
+    const normalizedTitle = title ? title.trim() : '';
+
+    return {
+      index,
+      title: normalizedTitle,
+      subtitle: subtitle || '',
+      content,
+      duration: customDuration !== null ? customDuration : this.calculateDuration(content)
+    };
+  }
+
+  /**
+   * Calculate recommended duration for slide based on content
+   */
+  calculateDuration(content) {
+    let duration = 3; // Base duration in seconds
+
+    content.forEach(item => {
+      switch (item.type) {
+        case 'h1':
+          duration += 2;
+          break;
+        case 'h2':
+        case 'h3':
+          duration += 1.5;
+          break;
+        case 'h4':
+        case 'h5':
+        case 'h6':
+          duration += 1;
+          break;
+        case 'list-item':
+        case 'numbered-item':
+        case 'task-list':
+          duration += 1;
+          break;
+        case 'code':
+          const lines = item.content.split('\n').length;
+          duration += Math.min(lines * 0.5, 10); // Max 10 seconds for code
+          break;
+        case 'blockquote':
+          const words = item.content.split(' ').length;
+          duration += words * 0.4; // Quotes need more reading time
+          break;
+        case 'text':
+          const textWords = item.content.split(' ').length;
+          duration += textWords * 0.3; // ~200 words per minute
+          break;
+        case 'image':
+          duration += 3;
+          break;
+        case 'table':
+          const rows = item.rows ? item.rows.length : 1;
+          duration += rows * 1.5; // Tables need time to understand
+          break;
+        case 'html':
+          duration += 2; // HTML content
+          break;
+        case 'hr':
+          duration += 0.5; // Separator
+          break;
+        default:
+          duration += 1;
+      }
+    });
+
+    return Math.round(duration);
+  }
+
+  /**
+   * Parse inline markdown (bold, italic, code, strikethrough, etc.)
+   * Uses Markdown Dictionary for comprehensive syntax support
+   */
+  parseInline(text) {
+    if (!text) return '';
+    
+    // Use the dictionary's parseInline function
+    return parseInline(text);
+  }
+
+  /**
+   * Get summary of parsed markdown
+   */
+  getSummary(slides) {
+    const totalPages = slides.reduce((sum, slide) => {
+      return sum + (slide.totalPages || 1);
+    }, 0);
+    
+    return {
+      totalSlides: slides.length,
+      totalPages: totalPages,
+      estimatedDuration: slides.reduce((sum, slide) => sum + slide.duration, 0),
+      titles: slides.map(slide => slide.title),
+      paginatedSlides: slides.filter(s => s.totalPages > 1).length
+    };
+  }
+  
+  /**
+   * Get pagination info for a slide without parsing
+   */
+  getPaginationPreview(slideContent) {
+    return getPaginationInfo(slideContent);
+  }
+}
+
+// Export helper function
+export function parseMarkdown(markdown, options = {}) {
+  const parser = new MarkdownParser(options);
+  return parser.parse(markdown);
+}

src/shared/markdown-syntax.js

@@ -0,0 +1,433 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Markdown Syntax Dictionary
+// Complete Markdown syntax patterns and recognition rules
+// ══════════════════════════════════════════════════════════════════════════════
+
+/**
+ * Markdown Syntax Dictionary
+ * Based on CommonMark + GitHub Flavored Markdown (GFM)
+ */
+export const MarkdownSyntax = {
+  // ════════════════════════════════════════════════════════════════════════════
+  // Block-level Elements
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  blocks: {
+    // Headings: # H1, ## H2, ### H3, #### H4, ##### H5, ###### H6
+    heading: {
+      patterns: [
+        /^(#{1,6})\s+(.+)$/,           // ATX style: # Heading
+        /^(.+)\n={3,}\s*$/,             // Setext H1: underline with ===
+        /^(.+)\n-{3,}\s*$/              // Setext H2: underline with ---
+      ],
+      detect: (line, nextLine) => {
+        // ATX headings
+        const atx = line.match(/^(#{1,6})\s+(.+)$/);
+        if (atx) {
+          return {
+            type: 'heading',
+            level: atx[1].length,
+            content: atx[2].trim(),
+            style: 'atx'
+          };
+        }
+        
+        // Setext headings (require next line)
+        if (nextLine) {
+          if (nextLine.match(/^={3,}\s*$/)) {
+            return { type: 'heading', level: 1, content: line.trim(), style: 'setext' };
+          }
+          if (nextLine.match(/^-{3,}\s*$/) && !line.match(/^\s*$/)) {
+            return { type: 'heading', level: 2, content: line.trim(), style: 'setext' };
+          }
+        }
+        
+        return null;
+      }
+    },
+    
+    // Horizontal Rules: ---, ***, ___
+    hr: {
+      patterns: [
+        /^-{3,}\s*$/,
+        /^\*{3,}\s*$/,
+        /^_{3,}\s*$/,
+        /^- {0,2}- {0,2}-/,
+        /^\* {0,2}\* {0,2}\*/,
+        /^_ {0,2}_ {0,2}_/
+      ],
+      detect: (line) => {
+        for (const pattern of MarkdownSyntax.blocks.hr.patterns) {
+          if (pattern.test(line.trim())) {
+            return { type: 'hr' };
+          }
+        }
+        return null;
+      }
+    },
+    
+    // Code Blocks: ```lang or indented 4 spaces
+    codeBlock: {
+      patterns: [
+        /^```(\w*)\s*$/,                // Fenced code block start
+        /^~~~(\w*)\s*$/,                // Alternative fence
+        /^    (.+)$/,                   // Indented code (4 spaces)
+        /^\t(.+)$/                      // Indented code (tab)
+      ],
+      detect: (line) => {
+        // Fenced code block
+        const fenced = line.match(/^```(\w*)\s*$/);
+        if (fenced) {
+          return { type: 'code-fence-start', language: fenced[1] || 'text' };
+        }
+        
+        const tilde = line.match(/^~~~(\w*)\s*$/);
+        if (tilde) {
+          return { type: 'code-fence-start', language: tilde[1] || 'text', fence: '~~~' };
+        }
+        
+        // Indented code
+        if (line.match(/^    (.+)$/) || line.match(/^\t(.+)$/)) {
+          return { type: 'code-indented', content: line.replace(/^    |\t/, '') };
+        }
+        
+        return null;
+      }
+    },
+    
+    // Blockquotes: > Quote
+    blockquote: {
+      patterns: [
+        /^>\s?(.*)$/,                   // > Quote
+        /^> ?> ?(.*)$/                  // Nested: >> Quote
+      ],
+      detect: (line) => {
+        const match = line.match(/^(>+)\s?(.*)$/);
+        if (match) {
+          return {
+            type: 'blockquote',
+            level: match[1].length,
+            content: match[2]
+          };
+        }
+        return null;
+      }
+    },
+    
+    // Lists: Unordered (-, *, +) and Ordered (1., 2.)
+    list: {
+      patterns: [
+        /^(\s*)([-*+])\s+(.+)$/,        // Unordered: -, *, +
+        /^(\s*)(\d{1,9})[.)]\s+(.+)$/   // Ordered: 1., 2), etc.
+      ],
+      detect: (line) => {
+        // Unordered list
+        const unordered = line.match(/^(\s*)([-*+])\s+(.+)$/);
+        if (unordered) {
+          return {
+            type: 'list',
+            ordered: false,
+            indent: unordered[1].length,
+            marker: unordered[2],
+            content: unordered[3]
+          };
+        }
+        
+        // Ordered list
+        const ordered = line.match(/^(\s*)(\d{1,9})[.)]\s+(.+)$/);
+        if (ordered) {
+          return {
+            type: 'list',
+            ordered: true,
+            indent: ordered[1].length,
+            number: parseInt(ordered[2]),
+            content: ordered[3]
+          };
+        }
+        
+        return null;
+      }
+    },
+    
+    // Task Lists (GFM): - [ ] Task or - [x] Done
+    taskList: {
+      patterns: [
+        /^(\s*)([-*+])\s+\[([ xX])\]\s+(.+)$/
+      ],
+      detect: (line) => {
+        const match = line.match(/^(\s*)([-*+])\s+\[([ xX])\]\s+(.+)$/);
+        if (match) {
+          return {
+            type: 'task-list',
+            indent: match[1].length,
+            checked: match[3].toLowerCase() === 'x',
+            content: match[4]
+          };
+        }
+        return null;
+      }
+    },
+    
+    // Tables (GFM): | Header | Header |
+    table: {
+      patterns: [
+        /^\|(.+)\|$/,                   // Table row
+        /^\|?\s*:?-+:?\s*(\|\s*:?-+:?\s*)+\|?$/ // Separator
+      ],
+      detect: (line) => {
+        if (line.match(/^\|(.+)\|$/)) {
+          return { type: 'table-row', cells: line.split('|').filter(c => c.trim()) };
+        }
+        if (line.match(/^\|?\s*:?-+:?\s*(\|\s*:?-+:?\s*)+\|?$/)) {
+          return { type: 'table-separator' };
+        }
+        return null;
+      }
+    },
+    
+    // HTML Blocks: <div>, <!-- comment -->
+    html: {
+      patterns: [
+        /^<([a-z][a-z0-9-]*)\b[^>]*>/i, // Opening tag
+        /^<\/([a-z][a-z0-9-]*)\s*>/i,   // Closing tag
+        /^<!--/,                         // Comment start
+        /^<\?/,                          // Processing instruction
+        /^<![A-Z]/,                      // Declaration
+        /^<!\[CDATA\[/                   // CDATA section
+      ],
+      detect: (line) => {
+        for (const pattern of MarkdownSyntax.blocks.html.patterns) {
+          if (pattern.test(line.trim())) {
+            return { type: 'html', content: line };
+          }
+        }
+        return null;
+      }
+    },
+    
+    // Metadata blocks (YAML frontmatter, TOML, JSON)
+    metadata: {
+      patterns: [
+        /^---\s*$/,     // YAML
+        /^\+\+\+\s*$/,  // TOML
+        /^;;;\s*$/      // JSON (some parsers)
+      ],
+      detect: (line) => {
+        if (line.trim() === '---') return { type: 'metadata', format: 'yaml' };
+        if (line.trim() === '+++') return { type: 'metadata', format: 'toml' };
+        if (line.trim() === ';;;') return { type: 'metadata', format: 'json' };
+        return null;
+      }
+    }
+  },
+  
+  // ════════════════════════════════════════════════════════════════════════════
+  // Inline Elements
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  inline: {
+    // Emphasis: *italic*, _italic_, **bold**, __bold__, ***bold italic***
+    emphasis: {
+      patterns: [
+        { regex: /\*\*\*(.+?)\*\*\*/g, type: 'bold-italic', tag: 'strong-em' },
+        { regex: /___(.+?)___/g, type: 'bold-italic', tag: 'strong-em' },
+        { regex: /\*\*(.+?)\*\*/g, type: 'bold', tag: 'strong' },
+        { regex: /__(.+?)__/g, type: 'bold', tag: 'strong' },
+        { regex: /\*(.+?)\*/g, type: 'italic', tag: 'em' },
+        { regex: /_(.+?)_/g, type: 'italic', tag: 'em' }
+      ]
+    },
+    
+    // Strikethrough (GFM): ~~deleted~~
+    strikethrough: {
+      patterns: [
+        { regex: /~~(.+?)~~/g, type: 'strikethrough', tag: 'del' }
+      ]
+    },
+    
+    // Code: `inline code`
+    code: {
+      patterns: [
+        { regex: /``(.+?)``/g, type: 'code', tag: 'code' },  // Double backtick
+        { regex: /`(.+?)`/g, type: 'code', tag: 'code' }      // Single backtick
+      ]
+    },
+    
+    // Links: [text](url "title"), [text][ref], <url>
+    link: {
+      patterns: [
+        { regex: /\[([^\]]+)\]\(([^)\s]+)(?:\s+"([^"]+)")?\)/g, type: 'link' },     // Inline
+        { regex: /\[([^\]]+)\]\[([^\]]+)\]/g, type: 'link-ref' },                   // Reference
+        { regex: /\[([^\]]+)\]/g, type: 'link-shortcut' },                          // Shortcut
+        { regex: /<(https?:\/\/[^>]+)>/g, type: 'autolink' },                       // Autolink
+        { regex: /<([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})>/g, type: 'email' } // Email
+      ]
+    },
+    
+    // Images: ![alt](url "title"), ![alt][ref]
+    image: {
+      patterns: [
+        { regex: /!\[([^\]]*)\]\(([^)\s]+)(?:\s+"([^"]+)")?\)/g, type: 'image' },   // Inline
+        { regex: /!\[([^\]]*)\]\[([^\]]+)\]/g, type: 'image-ref' }                  // Reference
+      ]
+    },
+    
+    // Line breaks: two spaces + newline, backslash + newline, <br>
+    lineBreak: {
+      patterns: [
+        { regex: /  \n/g, type: 'soft-break' },
+        { regex: /\\\n/g, type: 'hard-break' },
+        { regex: /<br\s*\/?>/gi, type: 'html-break' }
+      ]
+    },
+    
+    // Escape sequences: \*, \[, etc.
+    escape: {
+      characters: ['\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '#', '+', '-', '.', '!', '|']
+    },
+    
+    // Emoji (GFM): :smile:, :heart:
+    emoji: {
+      pattern: /:([a-z0-9_+-]+):/g
+    },
+    
+    // Mentions (GFM): @username
+    mention: {
+      pattern: /@([a-zA-Z0-9_-]+)/g
+    },
+    
+    // Hashtags: #tag
+    hashtag: {
+      pattern: /#([a-zA-Z0-9_-]+)/g
+    }
+  },
+  
+  // ════════════════════════════════════════════════════════════════════════════
+  // Special Constructs
+  // ════════════════════════════════════════════════════════════════════════════
+  
+  special: {
+    // Footnotes: [^1], [^note]
+    footnote: {
+      definition: /^\[\^([^\]]+)\]:\s+(.+)$/,
+      reference: /\[\^([^\]]+)\]/g
+    },
+    
+    // Abbreviations: *[HTML]: Hyper Text Markup Language
+    abbreviation: {
+      pattern: /^\*\[([^\]]+)\]:\s+(.+)$/
+    },
+    
+    // Definition lists:
+    // Term
+    // : Definition
+    definitionList: {
+      term: /^([^\n:]+)\s*$/,
+      definition: /^:\s+(.+)$/
+    },
+    
+    // Math (KaTeX/MathJax): $inline$, $$block$$
+    math: {
+      inline: /\$([^$]+)\$/g,
+      block: /\$\$([^$]+)\$\$/g
+    }
+  }
+};
+
+/**
+ * Check if a line matches any block-level syntax
+ */
+export function detectBlockType(line, nextLine = null) {
+  // Check each block type
+  for (const [blockName, block] of Object.entries(MarkdownSyntax.blocks)) {
+    const result = block.detect(line, nextLine);
+    if (result) {
+      return result;
+    }
+  }
+  return { type: 'paragraph' };
+}
+
+/**
+ * Parse inline markdown syntax
+ */
+function escapeHtml(str) {
+  if (str == null) return '';
+  return String(str)
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#39;');
+}
+
+export function parseInline(text) {
+  if (!text) return '';
+
+  let result = escapeHtml(text);
+
+  // Images (handle before links so the leading ! is preserved)
+  result = result.replace(/!\[([^\]]*)\]\(([^)\s]+)(?:\s+"([^"]+)")?\)/g, (match, alt, url, title) => {
+    const altAttr = escapeHtml(alt || '');
+    const srcAttr = escapeHtml(url || '');
+    const titleAttr = title ? ` title="${escapeHtml(title)}"` : '';
+    return `<img src="${srcAttr}" alt="${altAttr}"${titleAttr}>`;
+  });
+
+  // Inline links [text](url "title")
+  result = result.replace(/\[([^\]]+)\]\(([^)\s]+)(?:\s+"([^"]+)")?\)/g, (match, label, url, title) => {
+    const textContent = escapeHtml(label || '');
+    const hrefAttr = escapeHtml(url || '#');
+    const titleAttr = title ? ` title="${escapeHtml(title)}"` : '';
+    return `<a href="${hrefAttr}"${titleAttr}>${textContent}</a>`;
+  });
+
+  // Autolinks <https://example.com>
+  result = result.replace(/&lt;(https?:\/\/[^&]+)&gt;/g, (match, url) => {
+    const hrefAttr = escapeHtml(url);
+    return `<a href="${hrefAttr}">${hrefAttr}</a>`;
+  });
+
+  // Email autolinks <user@example.com>
+  result = result.replace(/&lt;([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})&gt;/g, (match, email) => {
+    const mailto = `mailto:${email}`;
+    return `<a href="${escapeHtml(mailto)}">${escapeHtml(email)}</a>`;
+  });
+
+  // Emphasis and code (process complex patterns first)
+  const replacements = [
+    { regex: /\*\*\*(.+?)\*\*\*/g, wrap: content => `<strong><em>${content}</em></strong>` },
+    { regex: /___(.+?)___/g, wrap: content => `<strong><em>${content}</em></strong>` },
+    { regex: /\*\*(.+?)\*\*/g, wrap: content => `<strong>${content}</strong>` },
+    { regex: /__(.+?)__/g, wrap: content => `<strong>${content}</strong>` },
+    { regex: /\*(.+?)\*/g, wrap: content => `<em>${content}</em>` },
+    { regex: /_(.+?)_/g, wrap: content => `<em>${content}</em>` },
+    { regex: /~~(.+?)~~/g, wrap: content => `<del>${content}</del>` },
+    { regex: /``(.+?)``/g, wrap: content => `<code>${content}</code>` },
+    { regex: /`(.+?)`/g, wrap: content => `<code>${content}</code>` }
+  ];
+
+  replacements.forEach(({ regex, wrap }) => {
+    result = result.replace(regex, (match, content) => wrap(content));
+  });
+
+  // Line breaks
+  result = result.replace(/  \n/g, '<br>');
+  result = result.replace(/\\\n/g, '<br>');
+  result = result.replace(/&lt;br\s*\/?&gt;/gi, '<br>');
+
+  return result;
+}
+
+/**
+ * Get syntax info for documentation
+ */
+export function getSyntaxInfo(category) {
+  const info = {
+    blocks: 'Block-level elements (headings, lists, code blocks, etc.)',
+    inline: 'Inline elements (emphasis, links, images, etc.)',
+    special: 'Special constructs (footnotes, math, definitions, etc.)'
+  };
+  
+  return info[category] || 'Unknown category';
+}

src/shared/persistent-storage.js

@@ -0,0 +1,535 @@
+/**
+ * Persistent Storage Manager
+ * 
+ * จัดการการบันทึกและโหลดการตั้งค่าทั้งหมด (positions, edits, layouts)
+ * รองรับ localStorage และ Export/Import JSON
+ * Auto-save ทุก 2-3 วินาที
+ * 
+ * @author Chahua Development Co., Ltd.
+ * @version 2.1.0
+ */
+
+export class PersistentStorage {
+    constructor() {
+        this.currentFilePath = null;
+        this.autoSaveInterval = null;
+        this.autoSaveDelay = 2000; // 2 วินาที
+        this.hasUnsavedChanges = false;
+        
+        // Storage keys
+        this.STORAGE_PREFIX = 'chahua-md-presenter';
+        this.POSITIONS_KEY = 'positions';
+        this.EDITS_KEY = 'edits';
+        this.LAYOUTS_KEY = 'layouts';
+        this.SETTINGS_KEY = 'settings';
+        
+        this.init();
+    }
+
+    init() {
+        // Listen for changes
+        this.setupEventListeners();
+        
+        // Auto-save on window close
+        window.addEventListener('beforeunload', () => {
+            if (this.hasUnsavedChanges) {
+                this.save();
+            }
+        });
+    }
+
+    /**
+     * Setup event listeners สำหรับ auto-save
+     */
+    setupEventListeners() {
+        // Listen for position changes
+        document.addEventListener('positionChanged', () => {
+            this.hasUnsavedChanges = true;
+            this.scheduleAutoSave();
+        });
+
+        // Listen for content changes
+        document.addEventListener('contentChanged', () => {
+            this.hasUnsavedChanges = true;
+            this.scheduleAutoSave();
+        });
+
+        // Listen for layout changes
+        document.addEventListener('layoutChanged', () => {
+            this.hasUnsavedChanges = true;
+            this.scheduleAutoSave();
+        });
+    }
+
+    /**
+     * กำหนดไฟล์ปัจจุบัน
+     * 
+     * @param {string} filePath 
+     */
+    setCurrentFile(filePath) {
+        this.currentFilePath = filePath;
+    }
+
+    /**
+     * สร้าง storage key จาก file path และ slide index
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @param {string} dataType - 'positions', 'edits', 'layouts', 'settings'
+     * @returns {string}
+     */
+    getStorageKey(filePath, slideIndex = null, dataType = 'positions') {
+        const cleanPath = this.sanitizeFilePath(filePath);
+        const slideKey = slideIndex !== null ? `:slide-${slideIndex}` : '';
+        return `${this.STORAGE_PREFIX}:${cleanPath}${slideKey}:${dataType}`;
+    }
+
+    /**
+     * Sanitize file path สำหรับใช้เป็น key
+     * 
+     * @param {string} filePath 
+     * @returns {string}
+     */
+    sanitizeFilePath(filePath) {
+        if (!filePath) return 'untitled';
+        
+        // แปลง path เป็น hash เพื่อให้สั้นลง
+        return this.simpleHash(filePath);
+    }
+
+    /**
+     * Simple hash function
+     * 
+     * @param {string} str 
+     * @returns {string}
+     */
+    simpleHash(str) {
+        let hash = 0;
+        for (let i = 0; i < str.length; i++) {
+            const char = str.charCodeAt(i);
+            hash = ((hash << 5) - hash) + char;
+            hash = hash & hash;
+        }
+        return Math.abs(hash).toString(36);
+    }
+
+    /**
+     * บันทึก positions สำหรับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @param {Object} positions 
+     */
+    savePositions(filePath, slideIndex, positions) {
+        const key = this.getStorageKey(filePath, slideIndex, this.POSITIONS_KEY);
+        const data = {
+            timestamp: Date.now(),
+            filePath,
+            slideIndex,
+            positions
+        };
+        
+        try {
+            localStorage.setItem(key, JSON.stringify(data));
+            return true;
+        } catch (error) {
+            console.error('Failed to save positions:', error);
+            return false;
+        }
+    }
+
+    /**
+     * โหลด positions สำหรับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @returns {Object|null}
+     */
+    loadPositions(filePath, slideIndex) {
+        const key = this.getStorageKey(filePath, slideIndex, this.POSITIONS_KEY);
+        
+        try {
+            const data = localStorage.getItem(key);
+            if (!data) return null;
+            
+            const parsed = JSON.parse(data);
+            return parsed.positions;
+        } catch (error) {
+            console.error('Failed to load positions:', error);
+            return null;
+        }
+    }
+
+    /**
+     * บันทึก content edits สำ��รับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @param {Object} edits 
+     */
+    saveEdits(filePath, slideIndex, edits) {
+        const key = this.getStorageKey(filePath, slideIndex, this.EDITS_KEY);
+        const data = {
+            timestamp: Date.now(),
+            filePath,
+            slideIndex,
+            edits
+        };
+        
+        try {
+            localStorage.setItem(key, JSON.stringify(data));
+            return true;
+        } catch (error) {
+            console.error('Failed to save edits:', error);
+            return false;
+        }
+    }
+
+    /**
+     * โหลด content edits สำหรับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @returns {Object|null}
+     */
+    loadEdits(filePath, slideIndex) {
+        const key = this.getStorageKey(filePath, slideIndex, this.EDITS_KEY);
+        
+        try {
+            const data = localStorage.getItem(key);
+            if (!data) return null;
+            
+            const parsed = JSON.parse(data);
+            return parsed.edits;
+        } catch (error) {
+            console.error('Failed to load edits:', error);
+            return null;
+        }
+    }
+
+    /**
+     * บันทึก layout settings สำหรับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @param {Object} layout 
+     */
+    saveLayout(filePath, slideIndex, layout) {
+        const key = this.getStorageKey(filePath, slideIndex, this.LAYOUTS_KEY);
+        const data = {
+            timestamp: Date.now(),
+            filePath,
+            slideIndex,
+            layout
+        };
+        
+        try {
+            localStorage.setItem(key, JSON.stringify(data));
+            return true;
+        } catch (error) {
+            console.error('Failed to save layout:', error);
+            return false;
+        }
+    }
+
+    /**
+     * โหลด layout settings สำหรับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     * @returns {Object|null}
+     */
+    loadLayout(filePath, slideIndex) {
+        const key = this.getStorageKey(filePath, slideIndex, this.LAYOUTS_KEY);
+        
+        try {
+            const data = localStorage.getItem(key);
+            if (!data) return null;
+            
+            const parsed = JSON.parse(data);
+            return parsed.layout;
+        } catch (error) {
+            console.error('Failed to load layout:', error);
+            return null;
+        }
+    }
+
+    /**
+     * บันทึกทุกอย่างสำหรับไฟล์ปัจจุบัน
+     * 
+     * @param {Array} allData - Array of {slideIndex, positions, edits, layout}
+     */
+    saveAll(filePath, allData) {
+        let savedCount = 0;
+        
+        allData.forEach(slideData => {
+            const { slideIndex, positions, edits, layout } = slideData;
+            
+            if (positions) {
+                this.savePositions(filePath, slideIndex, positions);
+                savedCount++;
+            }
+            
+            if (edits) {
+                this.saveEdits(filePath, slideIndex, edits);
+                savedCount++;
+            }
+            
+            if (layout) {
+                this.saveLayout(filePath, slideIndex, layout);
+                savedCount++;
+            }
+        });
+        
+        this.hasUnsavedChanges = false;
+        return savedCount;
+    }
+
+    /**
+     * โหลดทุกอย่างสำหรับไฟล์ปัจจุบัน
+     * 
+     * @param {string} filePath 
+     * @param {number} totalSlides 
+     * @returns {Array}
+     */
+    loadAll(filePath, totalSlides) {
+        const allData = [];
+        
+        for (let i = 0; i < totalSlides; i++) {
+            const positions = this.loadPositions(filePath, i);
+            const edits = this.loadEdits(filePath, i);
+            const layout = this.loadLayout(filePath, i);
+            
+            if (positions || edits || layout) {
+                allData.push({
+                    slideIndex: i,
+                    positions,
+                    edits,
+                    layout
+                });
+            }
+        }
+        
+        return allData;
+    }
+
+    /**
+     * Export ทุกอย่างเป็น JSON file
+     * 
+     * @param {string} filePath 
+     * @param {number} totalSlides 
+     * @returns {string} - JSON string
+     */
+    exportToJSON(filePath, totalSlides) {
+        const allData = this.loadAll(filePath, totalSlides);
+        
+        const exportData = {
+            version: '2.1.0',
+            exportedAt: new Date().toISOString(),
+            filePath,
+            totalSlides,
+            slides: allData
+        };
+        
+        return JSON.stringify(exportData, null, 2);
+    }
+
+    /**
+     * Import จาก JSON file
+     * 
+     * @param {string} jsonString 
+     * @returns {boolean}
+     */
+    importFromJSON(jsonString) {
+        try {
+            const data = JSON.parse(jsonString);
+            
+            if (!data.version || !data.slides) {
+                throw new Error('Invalid JSON format');
+            }
+            
+            const { filePath, slides } = data;
+            
+            slides.forEach(slideData => {
+                const { slideIndex, positions, edits, layout } = slideData;
+                
+                if (positions) {
+                    this.savePositions(filePath, slideIndex, positions);
+                }
+                
+                if (edits) {
+                    this.saveEdits(filePath, slideIndex, edits);
+                }
+                
+                if (layout) {
+                    this.saveLayout(filePath, slideIndex, layout);
+                }
+            });
+            
+            return true;
+        } catch (error) {
+            console.error('Failed to import JSON:', error);
+            return false;
+        }
+    }
+
+    /**
+     * Download JSON file
+     * 
+     * @param {string} filePath 
+     * @param {number} totalSlides 
+     */
+    downloadJSON(filePath, totalSlides) {
+        const json = this.exportToJSON(filePath, totalSlides);
+        const blob = new Blob([json], { type: 'application/json' });
+        const url = URL.createObjectURL(blob);
+        
+        const a = document.createElement('a');
+        a.href = url;
+        a.download = `presentation-settings-${Date.now()}.json`;
+        document.body.appendChild(a);
+        a.click();
+        document.body.removeChild(a);
+        URL.revokeObjectURL(url);
+    }
+
+    /**
+     * Schedule auto-save
+     */
+    scheduleAutoSave() {
+        if (this.autoSaveInterval) {
+            clearTimeout(this.autoSaveInterval);
+        }
+        
+        this.autoSaveInterval = setTimeout(() => {
+            this.save();
+        }, this.autoSaveDelay);
+    }
+
+    /**
+     * บันทึกทันที (manual save)
+     */
+    save() {
+        if (!this.hasUnsavedChanges) return;
+        
+        // Trigger save event
+        const event = new CustomEvent('persistentStorageSave', {
+            detail: {
+                filePath: this.currentFilePath,
+                timestamp: Date.now()
+            }
+        });
+        document.dispatchEvent(event);
+        
+        this.hasUnsavedChanges = false;
+    }
+
+    /**
+     * ลบข้อมูลสำหรับ slide หนึ่ง
+     * 
+     * @param {string} filePath 
+     * @param {number} slideIndex 
+     */
+    clearSlide(filePath, slideIndex) {
+        const posKey = this.getStorageKey(filePath, slideIndex, this.POSITIONS_KEY);
+        const editKey = this.getStorageKey(filePath, slideIndex, this.EDITS_KEY);
+        const layoutKey = this.getStorageKey(filePath, slideIndex, this.LAYOUTS_KEY);
+        
+        localStorage.removeItem(posKey);
+        localStorage.removeItem(editKey);
+        localStorage.removeItem(layoutKey);
+    }
+
+    /**
+     * ลบข้อมูลทั้งหมดสำหรับไฟล์หนึ่ง
+     * 
+     * @param {string} filePath 
+     */
+    clearFile(filePath) {
+        const prefix = `${this.STORAGE_PREFIX}:${this.sanitizeFilePath(filePath)}`;
+        
+        // หา keys ทั้งหมดที่ตรงกับ prefix
+        const keysToRemove = [];
+        for (let i = 0; i < localStorage.length; i++) {
+            const key = localStorage.key(i);
+            if (key.startsWith(prefix)) {
+                keysToRemove.push(key);
+            }
+        }
+        
+        // ลบทั้งหมด
+        keysToRemove.forEach(key => localStorage.removeItem(key));
+    }
+
+    /**
+     * ลบข้อมูลทั้งหมด
+     */
+    clearAll() {
+        const keysToRemove = [];
+        for (let i = 0; i < localStorage.length; i++) {
+            const key = localStorage.key(i);
+            if (key.startsWith(this.STORAGE_PREFIX)) {
+                keysToRemove.push(key);
+            }
+        }
+        
+        keysToRemove.forEach(key => localStorage.removeItem(key));
+    }
+
+    /**
+     * Get storage usage info
+     * 
+     * @returns {Object}
+     */
+    getStorageInfo() {
+        let totalSize = 0;
+        let itemCount = 0;
+        
+        for (let i = 0; i < localStorage.length; i++) {
+            const key = localStorage.key(i);
+            if (key.startsWith(this.STORAGE_PREFIX)) {
+                const value = localStorage.getItem(key);
+                totalSize += key.length + value.length;
+                itemCount++;
+            }
+        }
+        
+        return {
+            itemCount,
+            totalSize,
+            totalSizeKB: (totalSize / 1024).toFixed(2),
+            maxSize: 5120, // 5MB typical localStorage limit
+            usagePercent: ((totalSize / (5 * 1024 * 1024)) * 100).toFixed(2)
+        };
+    }
+
+    /**
+     * Cleanup old data (optional)
+     * ลบข้อมูลที่เก่ากว่า X วัน
+     * 
+     * @param {number} daysOld 
+     */
+    cleanupOldData(daysOld = 30) {
+        const cutoffTime = Date.now() - (daysOld * 24 * 60 * 60 * 1000);
+        const keysToRemove = [];
+        
+        for (let i = 0; i < localStorage.length; i++) {
+            const key = localStorage.key(i);
+            if (!key.startsWith(this.STORAGE_PREFIX)) continue;
+            
+            try {
+                const data = JSON.parse(localStorage.getItem(key));
+                if (data.timestamp && data.timestamp < cutoffTime) {
+                    keysToRemove.push(key);
+                }
+            } catch (error) {
+                // Invalid JSON, skip
+            }
+        }
+        
+        keysToRemove.forEach(key => localStorage.removeItem(key));
+        return keysToRemove.length;
+    }
+}
+
+export default PersistentStorage;

src/shared/security-core.js

@@ -0,0 +1,600 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Chahua Video Builder - Security Core Module
+// ══════════════════════════════════════════════════════════════════════════════
+// Company: Chahua Development Co., Ltd.
+// Repository: https://github.com/chahuadev/chahuadev-Video-Builder.git
+// Version: 1.0.0
+// License: MIT
+// Contact: chahuadev@gmail.com
+// ══════════════════════════════════════════════════════════════════════════════
+// @description Enterprise-grade security module for video builder application
+// @security_level FORTRESS - Maximum Protection
+// ══════════════════════════════════════════════════════════════════════════════
+
+import fs from 'fs';
+import path from 'path';
+import crypto from 'crypto';
+
+// ╔══════════════════════════════════════════════════════════════════════════════════╗
+// ║                         Custom Error Classes - Zone 0                            ║
+// ║                     Enhanced Error Handling System                               ║
+// ╚══════════════════════════════════════════════════════════════════════════════════╝
+
+class SecurityError extends Error {
+    constructor(message, filePath = null, errorCode = 'SEC_001') {
+        super(message);
+        this.name = 'SecurityError';
+        this.filePath = filePath;
+        this.errorCode = errorCode;
+        this.timestamp = new Date().toISOString();
+    }
+}
+
+class PathTraversalError extends SecurityError {
+    constructor(message, filePath = null, attemptedPath = null) {
+        super(message, filePath, 'PATH_TRAVERSAL_001');
+        this.name = 'PathTraversalError';
+        this.attemptedPath = attemptedPath;
+    }
+}
+
+class SymlinkError extends SecurityError {
+    constructor(message, filePath = null, linkTarget = null) {
+        super(message, filePath, 'SYMLINK_001');
+        this.name = 'SymlinkError';
+        this.linkTarget = linkTarget;
+    }
+}
+
+class FileValidationError extends SecurityError {
+    constructor(message, filePath = null, reason = null) {
+        super(message, filePath, 'FILE_VAL_001');
+        this.name = 'FileValidationError';
+        this.reason = reason;
+    }
+}
+
+class ReDoSError extends SecurityError {
+    constructor(message, pattern = null, filePath = null) {
+        super(message, filePath, 'REDOS_001');
+        this.name = 'ReDoSError';
+        this.pattern = pattern;
+    }
+}
+
+class RateLimitError extends SecurityError {
+    constructor(message, operation = null) {
+        super(message, null, 'RATE_LIMIT_001');
+        this.name = 'RateLimitError';
+        this.operation = operation;
+    }
+}
+
+// ╔══════════════════════════════════════════════════════════════════════════════════╗
+// ║                         Security Configuration - Zone 1                          ║
+// ║                    System-wide Security Settings                                 ║
+// ╚══════════════════════════════════════════════════════════════════════════════════╝
+
+const SECURITY_CONFIG = {
+    // Path Security
+    MAX_PATH_LENGTH: 260,
+    ALLOWED_EXTENSIONS: [
+        '.js', '.ts', '.jsx', '.tsx', '.vue', '.svelte',
+        '.html', '.css', '.scss', '.sass', '.less',
+        '.py', '.java', '.cpp', '.c', '.cs', '.go', '.rs', '.rb',
+        '.php', '.pl', '.sh', '.bash', '.zsh',
+        '.yml', '.yaml', '.json', '.xml', '.toml',
+        '.md', '.txt', '.sql', '.lua', '.swift', '.kt', '.dart', '.scala'
+    ],
+    FORBIDDEN_PATHS: [
+        /^[A-Z]:\\Windows\\/i,
+        /^[A-Z]:\\Program Files\\/i,
+        /^\/etc\//,
+        /^\/usr\/bin\//,
+        /^\/System\//,
+        /^\/bin\//,
+        /^\/sbin\//,
+        /node_modules/,
+        /\.git/
+    ],
+    // Additional allowed directories (absolute paths). Empty by default.
+    EXTRA_ALLOWED_DIRS: [],
+    
+    // File Security
+    MAX_FILE_SIZE: 10 * 1024 * 1024, // 10MB
+    MIN_FILE_SIZE: 1, // 1 byte
+    
+    // Symlink Security
+    ALLOW_SYMLINKS: false,
+    MAX_SYMLINK_DEPTH: 3,
+    
+    // ReDoS Protection
+    ENABLE_REDOS_PROTECTION: true,
+    MAX_PATTERN_EXECUTION_TIME: 1000, // 1 second
+    REGEX_TIMEOUT: 5000, // 5 seconds
+    
+    // Rate Limiting
+    MAX_FILES_PER_SECOND: 50,
+    MAX_OPERATIONS_PER_MINUTE: 500,
+    RATE_LIMIT_WINDOW: 60000, // 1 minute
+    
+    // Content Security
+    MAX_ANIMATION_DURATION: 300000, // 5 minutes
+    MAX_BLOCKS_PER_FILE: 1000,
+    MAX_LINES_PER_BLOCK: 50,
+    
+    // Hash & Integrity
+    HASH_ALGORITHM: 'sha256',
+    VERIFY_FILE_INTEGRITY: true
+};
+
+// ╔══════════════════════════════════════════════════════════════════════════════════╗
+// ║                         Security Manager - Zone 2                                ║
+// ║                    Core Security Implementation                                  ║
+// ╚══════════════════════════════════════════════════════════════════════════════════╝
+
+class SecurityManager {
+    constructor(config = {}) {
+        this.config = { ...SECURITY_CONFIG, ...config };
+        this.rateLimitStore = new Map();
+        this.fileHashCache = new Map();
+        this.operationLog = [];
+        this.startTime = Date.now();
+    }
+
+    // ══════════════════════════════════════════════════════════════════════════════
+    //                         Input Validation Functions
+    // ══════════════════════════════════════════════════════════════════════════════
+
+    /**
+     * Validate user input for path traversal and malicious patterns
+     */
+    validateInput(target) {
+        if (!target || typeof target !== 'string') {
+            throw new SecurityError('Invalid input: target must be a non-empty string');
+        }
+
+        // Check for path traversal patterns (but allow absolute paths)
+        const dangerousPatterns = [
+            /\.\.[\/\\]/,           // ../ or ..\
+            /[<>"|?*]/,             // Invalid filename characters (allow : for Windows drives)
+            /\0/,                   // Null bytes
+            /[\x00-\x1f\x7f]/       // Control characters
+        ];
+
+        for (const pattern of dangerousPatterns) {
+            if (pattern.test(target)) {
+                throw new PathTraversalError(
+                    `Dangerous pattern detected in input: ${target}`,
+                    null,
+                    target
+                );
+            }
+        }
+
+        // Length validation
+        if (target.length > this.config.MAX_PATH_LENGTH) {
+            throw new PathTraversalError(
+                `Path too long: ${target.length} > ${this.config.MAX_PATH_LENGTH}`,
+                null,
+                target
+            );
+        }
+
+        return true;
+    }
+
+    /**
+     * Check if path is safe and not in forbidden directories
+     */
+    isPathSafe(targetPath) {
+        const normalizedPath = path.normalize(targetPath).replace(/\\/g, '/');
+
+        // Check against forbidden paths
+        for (const forbiddenPattern of this.config.FORBIDDEN_PATHS) {
+            if (forbiddenPattern.test(normalizedPath)) {
+                throw new PathTraversalError(
+                    `Access to forbidden path: ${targetPath}`,
+                    targetPath,
+                    normalizedPath
+                );
+            }
+        }
+
+        // Allow files within working directory OR workspace folder OR any EXTRA_ALLOWED_DIRS
+        const absolutePath = path.resolve(targetPath);
+        const workingDir = process.cwd();
+        const workspaceDir = path.join(workingDir, 'workspace');
+
+        const isInWorkingDir = absolutePath.startsWith(workingDir);
+        const isInWorkspace = absolutePath.startsWith(workspaceDir);
+
+        let isInExtra = false;
+        if (Array.isArray(this.config.EXTRA_ALLOWED_DIRS)) {
+            for (const extra of this.config.EXTRA_ALLOWED_DIRS) {
+                if (!extra) continue;
+                try {
+                    const absExtra = path.resolve(extra);
+                    if (absolutePath.startsWith(absExtra)) {
+                        isInExtra = true;
+                        break;
+                    }
+                } catch (e) {
+                    // ignore invalid entries
+                }
+            }
+        }
+
+        if (!isInWorkingDir && !isInWorkspace && !isInExtra) {
+            throw new PathTraversalError(
+                `Path outside allowed directories. Please copy files to workspace folder: ${workspaceDir}`,
+                targetPath,
+                absolutePath
+            );
+        }
+
+        return true;
+    }
+
+    /**
+     * Check symlink safety and prevent circular references
+     */
+    checkSymlinkSafety(filePath, depth = 0) {
+        if (!this.config.ALLOW_SYMLINKS) {
+            try {
+                const stats = fs.lstatSync(filePath);
+                if (stats.isSymbolicLink()) {
+                    throw new SymlinkError(
+                        'Symlinks are disabled by security policy',
+                        filePath,
+                        fs.readlinkSync(filePath)
+                    );
+                }
+            } catch (error) {
+                if (error instanceof SymlinkError) throw error;
+                // File doesn't exist or other error - will be caught by file validation
+            }
+        }
+
+        // Check symlink depth
+        if (depth > this.config.MAX_SYMLINK_DEPTH) {
+            throw new SymlinkError(
+                `Symlink depth exceeded: ${depth} > ${this.config.MAX_SYMLINK_DEPTH}`,
+                filePath,
+                null
+            );
+        }
+
+        return { safe: true, depth };
+    }
+
+    /**
+     * Validate file extension
+     */
+    validateFileExtension(filePath) {
+        const ext = path.extname(filePath).toLowerCase();
+        
+        if (!this.config.ALLOWED_EXTENSIONS.includes(ext)) {
+            throw new FileValidationError(
+                `File extension not allowed: ${ext}`,
+                filePath,
+                'INVALID_EXTENSION'
+            );
+        }
+
+        return true;
+    }
+
+    /**
+     * Validate file size
+     */
+    validateFileSize(filePath) {
+        try {
+            const stats = fs.statSync(filePath);
+            const size = stats.size;
+
+            if (size < this.config.MIN_FILE_SIZE) {
+                throw new FileValidationError(
+                    `File too small: ${size} bytes`,
+                    filePath,
+                    'FILE_TOO_SMALL'
+                );
+            }
+
+            if (size > this.config.MAX_FILE_SIZE) {
+                throw new FileValidationError(
+                    `File too large: ${size} > ${this.config.MAX_FILE_SIZE}`,
+                    filePath,
+                    'FILE_TOO_LARGE'
+                );
+            }
+
+            return { valid: true, size };
+        } catch (error) {
+            if (error instanceof FileValidationError) throw error;
+            throw new FileValidationError(
+                `Cannot validate file size: ${error.message}`,
+                filePath,
+                'STAT_ERROR'
+            );
+        }
+    }
+
+    /**
+     * Calculate file hash for integrity verification
+     */
+    calculateFileHash(filePath) {
+        try {
+            const content = fs.readFileSync(filePath);
+            const hash = crypto
+                .createHash(this.config.HASH_ALGORITHM)
+                .update(content)
+                .digest('hex');
+            
+            this.fileHashCache.set(filePath, {
+                hash,
+                timestamp: Date.now()
+            });
+
+            return hash;
+        } catch (error) {
+            throw new SecurityError(
+                `Failed to calculate file hash: ${error.message}`,
+                filePath,
+                'HASH_ERROR'
+            );
+        }
+    }
+
+    /**
+     * Verify file integrity
+     */
+    verifyFileIntegrity(filePath, expectedHash) {
+        const currentHash = this.calculateFileHash(filePath);
+        
+        if (currentHash !== expectedHash) {
+            throw new SecurityError(
+                'File integrity verification failed - file may have been tampered with',
+                filePath,
+                'INTEGRITY_ERROR'
+            );
+        }
+
+        return true;
+    }
+
+    // ══════════════════════════════════════════════════════════════════════════════
+    //                         Rate Limiting Functions
+    // ══════════════════════════════════════════════════════════════════════════════
+
+    /**
+     * Check rate limit for operations
+     */
+    checkRateLimit(operation) {
+        const now = Date.now();
+        const key = `${operation}_${now}`;
+        
+        // Clean old entries
+        for (const [k, v] of this.rateLimitStore.entries()) {
+            if (now - v.timestamp > this.config.RATE_LIMIT_WINDOW) {
+                this.rateLimitStore.delete(k);
+            }
+        }
+
+        // Count operations in current window
+        const recentOps = Array.from(this.rateLimitStore.values())
+            .filter(entry => 
+                entry.operation === operation &&
+                now - entry.timestamp < this.config.RATE_LIMIT_WINDOW
+            );
+
+        if (recentOps.length >= this.config.MAX_OPERATIONS_PER_MINUTE) {
+            throw new RateLimitError(
+                `Rate limit exceeded for operation: ${operation}`,
+                operation
+            );
+        }
+
+        // Record operation
+        this.rateLimitStore.set(key, {
+            operation,
+            timestamp: now
+        });
+
+        return true;
+    }
+
+    // ══════════════════════════════════════════════════════════════════════════════
+    //                         ReDoS Protection Functions
+    // ══════════════════════════════════════════════════════════════════════════════
+
+    /**
+     * Safe regex execution with timeout protection
+     */
+    safeRegexExecution(pattern, content, filePath = null) {
+        if (!this.config.ENABLE_REDOS_PROTECTION) {
+            return pattern.test(content);
+        }
+
+        const startTime = Date.now();
+        let timeoutId;
+        let result = false;
+
+        const timeoutPromise = new Promise((_, reject) => {
+            timeoutId = setTimeout(() => {
+                reject(new ReDoSError(
+                    'Regex execution timeout - possible ReDoS attack',
+                    pattern.toString(),
+                    filePath
+                ));
+            }, this.config.MAX_PATTERN_EXECUTION_TIME);
+        });
+
+        const executionPromise = new Promise((resolve) => {
+            result = pattern.test(content);
+            resolve(result);
+        });
+
+        return Promise.race([executionPromise, timeoutPromise])
+            .finally(() => {
+                clearTimeout(timeoutId);
+                const executionTime = Date.now() - startTime;
+                
+                if (executionTime > this.config.MAX_PATTERN_EXECUTION_TIME * 0.8) {
+                    console.warn(`[SECURITY] Slow regex execution: ${executionTime}ms`);
+                }
+            });
+    }
+
+    // ══════════════════════════════════════════════════════════════════════════════
+    //                         Complete File Validation
+    // ══════════════════════════════════════════════════════════════════════════════
+
+    /**
+     * Comprehensive file validation pipeline
+     */
+    async validateFile(filePath) {
+        try {
+            // 1. Resolve absolute path
+            const absolutePath = path.resolve(filePath);
+
+            // 2. Input validation
+            this.validateInput(absolutePath);
+
+            // 3. Path safety check
+            this.isPathSafe(absolutePath);
+
+            // 4. Symlink safety
+            this.checkSymlinkSafety(absolutePath);
+
+            // 5. File extension validation
+            this.validateFileExtension(absolutePath);
+
+            // 6. File size validation
+            const sizeInfo = this.validateFileSize(absolutePath);
+
+            // 7. Rate limit check
+            this.checkRateLimit(`file_access_${absolutePath}`);
+
+            // 8. Calculate hash for integrity
+            const hash = this.config.VERIFY_FILE_INTEGRITY 
+                ? this.calculateFileHash(absolutePath)
+                : null;
+
+            // Log successful validation
+            this.logOperation('FILE_VALIDATION_SUCCESS', {
+                filePath: absolutePath,
+                size: sizeInfo.size,
+                hash
+            });
+
+            return {
+                valid: true,
+                filePath: absolutePath,
+                size: sizeInfo.size,
+                hash,
+                timestamp: Date.now()
+            };
+
+        } catch (error) {
+            this.logOperation('FILE_VALIDATION_FAILED', {
+                filePath,
+                error: error.message,
+                errorType: error.name
+            });
+            throw error;
+        }
+    }
+
+    /**
+     * Read file with full security validation
+     */
+    async secureReadFile(filePath) {
+        const validation = await this.validateFile(filePath);
+        
+        try {
+            const content = fs.readFileSync(validation.filePath, 'utf8');
+            
+            return {
+                success: true,
+                content,
+                filePath: validation.filePath,
+                size: validation.size,
+                hash: validation.hash
+            };
+        } catch (error) {
+            throw new SecurityError(
+                `Failed to read file: ${error.message}`,
+                validation.filePath,
+                'READ_ERROR'
+            );
+        }
+    }
+
+    // ══════════════════════════════════════════════════════════════════════════════
+    //                         Logging & Monitoring
+    // ══════════════════════════════════════════════════════════════════════════════
+
+    /**
+     * Log security operations
+     */
+    logOperation(type, data) {
+        const entry = {
+            type,
+            timestamp: new Date().toISOString(),
+            data,
+            uptime: Date.now() - this.startTime
+        };
+
+        this.operationLog.push(entry);
+
+        // Keep only recent logs (last 1000)
+        if (this.operationLog.length > 1000) {
+            this.operationLog.shift();
+        }
+
+        // Console output in dev mode
+        if (process.env.NODE_ENV === 'development') {
+            console.log(`[SECURITY] ${type}:`, data);
+        }
+    }
+
+    /**
+     * Get security statistics
+     */
+    getSecurityStats() {
+        return {
+            totalOperations: this.operationLog.length,
+            uptime: Date.now() - this.startTime,
+            rateLimitEntries: this.rateLimitStore.size,
+            cachedHashes: this.fileHashCache.size,
+            config: this.config
+        };
+    }
+
+    /**
+     * Export security log
+     */
+    exportSecurityLog() {
+        return {
+            generatedAt: new Date().toISOString(),
+            stats: this.getSecurityStats(),
+            operations: this.operationLog
+        };
+    }
+}
+
+// ══════════════════════════════════════════════════════════════════════════════
+//                         Module Exports
+// ══════════════════════════════════════════════════════════════════════════════
+
+export {
+    SecurityManager,
+    SecurityError,
+    PathTraversalError,
+    SymlinkError,
+    FileValidationError,
+    ReDoSError,
+    RateLimitError,
+    SECURITY_CONFIG
+};

src/shared/slide-paginator.js

@@ -0,0 +1,362 @@
+// ══════════════════════════════════════════════════════════════════════════════
+// Slide Paginator - Auto-split slides based on visual line count
+// ══════════════════════════════════════════════════════════════════════════════
+
+/**
+ * Configuration for slide pagination
+ */
+export const PaginationConfig = {
+  maxLinesPerSlide: 6,           // Maximum visual lines per slide (reduced to prevent overflow)
+  minLinesForSplit: 4,           // Minimum lines to justify creating new slide
+  balanceThreshold: 0.3,         // Balance ratio for splitting (30%)
+  
+  // Visual line weights (how many lines each content type occupies)
+  visualLines: {
+    h1: 2.5,         // H1 takes 2.5 lines (large font with spacing)
+    h2: 2,           // H2 takes 2 lines
+    h3: 1.5,
+    h4: 1.2,
+    h5: 1,
+    h6: 1,
+    text: 1,         // Normal text = 1 line
+    'list-item': 1.2, // Lists need more space
+    'numbered-item': 1.2,
+    'task-list': 1.2,
+    'code-line': 1,   // Code lines are more readable at 1:1 ratio
+    blockquote: 1.2,
+    image: 4,        // Images take significant space
+    table: 2.5,      // Base table size
+    'table-row': 0.8, // Each table row
+    hr: 1,
+    html: 3,
+    link: 1
+  },
+  
+  // Block types that should NOT be split
+  atomicBlocks: ['image', 'html', 'hr'],
+  
+  // Block types that CAN be split into multiple parts
+  splittableBlocks: ['code', 'blockquote', 'table']
+};
+
+/**
+ * Calculate visual lines for a content item
+ */
+export function calculateVisualLines(item) {
+  const config = PaginationConfig;
+  
+  switch (item.type) {
+    case 'code':
+      const codeLines = item.content.split('\n').length;
+      return Math.ceil(codeLines * config.visualLines['code-line']) + 1; // +1 for wrapper
+    
+    case 'blockquote':
+      // Count lines in blockquote
+      const quoteLines = item.content.split('\n').length;
+      return quoteLines * config.visualLines.blockquote;
+    
+    case 'table':
+      const rows = item.rows ? item.rows.length : 0;
+      return config.visualLines.table + (rows * config.visualLines['table-row']);
+    
+    default:
+      return config.visualLines[item.type] || 1;
+  }
+}
+
+/**
+ * Calculate total visual lines for an array of content items
+ */
+export function calculateTotalLines(contentArray) {
+  return contentArray.reduce((total, item) => {
+    return total + calculateVisualLines(item);
+  }, 0);
+}
+
+/**
+ * Check if content exceeds max lines per slide
+ */
+export function needsPagination(contentArray) {
+  return calculateTotalLines(contentArray) > PaginationConfig.maxLinesPerSlide;
+}
+
+/**
+ * Split a code block into multiple parts
+ */
+function splitCodeBlock(codeItem, targetLines) {
+  const lines = codeItem.content.split('\n');
+  const linesPerPart = Math.ceil(targetLines / PaginationConfig.visualLines['code-line']);
+  const parts = [];
+  
+  for (let i = 0; i < lines.length; i += linesPerPart) {
+    parts.push({
+      type: 'code',
+      language: codeItem.language,
+      content: lines.slice(i, i + linesPerPart).join('\n'),
+      isContinuation: i > 0,
+      hasMore: i + linesPerPart < lines.length
+    });
+  }
+  
+  return parts;
+}
+
+/**
+ * Split a blockquote into multiple parts
+ */
+function splitBlockquote(quoteItem, targetLines) {
+  const lines = quoteItem.content.split('\n');
+  const parts = [];
+  
+  for (let i = 0; i < lines.length; i += targetLines) {
+    parts.push({
+      type: 'blockquote',
+      content: lines.slice(i, i + targetLines).join('\n'),
+      level: quoteItem.level,
+      isContinuation: i > 0,
+      hasMore: i + targetLines < lines.length
+    });
+  }
+  
+  return parts;
+}
+
+/**
+ * Split a table into multiple parts
+ */
+function splitTable(tableItem, targetLines) {
+  if (!tableItem.rows || tableItem.rows.length <= 2) {
+    return [tableItem]; // Too small to split
+  }
+  
+  const header = tableItem.rows[0];
+  const separator = tableItem.rows[1];
+  const dataRows = tableItem.rows.slice(2);
+  
+  const rowsPerPart = Math.max(2, Math.floor(targetLines / PaginationConfig.visualLines['table-row']));
+  const parts = [];
+  
+  for (let i = 0; i < dataRows.length; i += rowsPerPart) {
+    parts.push({
+      type: 'table',
+      rows: [
+        header,
+        separator,
+        ...dataRows.slice(i, i + rowsPerPart)
+      ],
+      isContinuation: i > 0,
+      hasMore: i + rowsPerPart < dataRows.length
+    });
+  }
+  
+  return parts;
+}
+
+/**
+ * Split a large content block into multiple parts
+ */
+function splitLargeBlock(item, availableLines) {
+  const targetLines = Math.max(3, availableLines);
+  
+  switch (item.type) {
+    case 'code':
+      return splitCodeBlock(item, targetLines);
+    case 'blockquote':
+      return splitBlockquote(item, targetLines);
+    case 'table':
+      return splitTable(item, targetLines);
+    default:
+      return [item]; // Can't split this type
+  }
+}
+
+/**
+ * Main pagination function - split content into multiple slides
+ */
+export function paginateContent(contentArray, slideInfo = {}) {
+  const config = PaginationConfig;
+  const slides = [];
+  let currentSlide = [];
+  let currentLines = 0;
+  
+  // Extract title and subtitle (they go on first slide only)
+  const title = slideInfo.title || '';
+  const subtitle = slideInfo.subtitle || '';
+  const titleLines = title ? config.visualLines.h1 : 0;
+  const subtitleLines = subtitle ? config.visualLines.h2 : 0;
+  const headerLines = titleLines + subtitleLines;
+  
+  for (let i = 0; i < contentArray.length; i++) {
+    const item = contentArray[i];
+    const itemLines = calculateVisualLines(item);
+    
+    // Check if this item is atomic (cannot be split)
+    const isAtomic = config.atomicBlocks.includes(item.type);
+    const isSplittable = config.splittableBlocks.includes(item.type);
+    
+    // Calculate available space in current slide
+    const usedLines = currentSlide.length === 0 ? headerLines : 0;
+    const availableLines = config.maxLinesPerSlide - currentLines - usedLines;
+    
+    // Case 1: Item fits in current slide
+    if (currentLines + itemLines <= config.maxLinesPerSlide - usedLines) {
+      currentSlide.push(item);
+      currentLines += itemLines;
+    }
+    // Case 2: Item is too large and can be split
+    else if (isSplittable && itemLines > config.maxLinesPerSlide / 2) {
+      // Try to use remaining space in current slide
+      if (availableLines >= config.minLinesForSplit) {
+        const parts = splitLargeBlock(item, availableLines);
+        
+        // Add first part to current slide
+        if (parts.length > 0) {
+          currentSlide.push(parts[0]);
+          currentLines += calculateVisualLines(parts[0]);
+        }
+        
+        // Start new slide if current is full
+        if (currentSlide.length > 0) {
+          slides.push({
+            content: currentSlide,
+            lines: currentLines,
+            pageNumber: slides.length + 1
+          });
+          currentSlide = [];
+          currentLines = 0;
+        }
+        
+        // Add remaining parts
+        for (let j = 1; j < parts.length; j++) {
+          const part = parts[j];
+          const partLines = calculateVisualLines(part);
+          
+          if (currentLines + partLines <= config.maxLinesPerSlide) {
+            currentSlide.push(part);
+            currentLines += partLines;
+          } else {
+            // Flush current slide
+            if (currentSlide.length > 0) {
+              slides.push({
+                content: currentSlide,
+                lines: currentLines,
+                pageNumber: slides.length + 1
+              });
+            }
+            // Start new slide with this part
+            currentSlide = [part];
+            currentLines = partLines;
+          }
+        }
+      } else {
+        // Not enough space, start new slide
+        if (currentSlide.length > 0) {
+          slides.push({
+            content: currentSlide,
+            lines: currentLines,
+            pageNumber: slides.length + 1
+          });
+        }
+        
+        // Split item across multiple slides
+        const parts = splitLargeBlock(item, config.maxLinesPerSlide);
+        for (const part of parts) {
+          slides.push({
+            content: [part],
+            lines: calculateVisualLines(part),
+            pageNumber: slides.length + 1
+          });
+        }
+        
+        currentSlide = [];
+        currentLines = 0;
+      }
+    }
+    // Case 3: Item doesn't fit and is atomic (must start new slide)
+    else {
+      // Flush current slide if not empty
+      if (currentSlide.length > 0) {
+        slides.push({
+          content: currentSlide,
+          lines: currentLines,
+          pageNumber: slides.length + 1
+        });
+      }
+      
+      // Start new slide with this item
+      currentSlide = [item];
+      currentLines = itemLines;
+    }
+  }
+  
+  // Add last slide
+  if (currentSlide.length > 0) {
+    slides.push({
+      content: currentSlide,
+      lines: currentLines,
+      pageNumber: slides.length + 1
+    });
+  }
+  
+  return slides;
+}
+
+/**
+ * Apply pagination to parsed slide and create multiple slides if needed
+ */
+export function applyPagination(slide) {
+  const totalLines = calculateTotalLines(slide.content);
+  
+  // No pagination needed
+  if (totalLines <= PaginationConfig.maxLinesPerSlide) {
+    return [{
+      ...slide,
+      visualLines: totalLines,
+      totalPages: 1,
+      pageNumber: 1
+    }];
+  }
+  
+  // Split into multiple pages
+  const pages = paginateContent(slide.content, {
+    title: slide.title,
+    subtitle: slide.subtitle
+  });
+  
+  // Create slide objects for each page
+  return pages.map((page, index) => ({
+    ...slide,
+    content: page.content,
+    visualLines: page.lines,
+    totalPages: pages.length,
+    pageNumber: index + 1,
+    title: !slide.title
+      ? ''
+      : index === 0
+        ? slide.title
+        : `${slide.title} (${index + 1}/${pages.length})`,
+    subtitle: index === 0 ? slide.subtitle : '',
+    // Adjust duration proportionally
+    duration: Math.ceil((slide.duration / pages.length) * 10) / 10
+  }));
+}
+
+/**
+ * Get pagination info for a content array
+ */
+export function getPaginationInfo(contentArray) {
+  const totalLines = calculateTotalLines(contentArray);
+  const needsSplit = totalLines > PaginationConfig.maxLinesPerSlide;
+  const estimatedPages = Math.ceil(totalLines / PaginationConfig.maxLinesPerSlide);
+  
+  return {
+    totalLines,
+    maxLinesPerSlide: PaginationConfig.maxLinesPerSlide,
+    needsPagination: needsSplit,
+    estimatedPages,
+    breakdown: contentArray.map(item => ({
+      type: item.type,
+      lines: calculateVisualLines(item)
+    }))
+  };
+}