docs/EN/MARKDOWN_VIDEO_PLAN.md


# 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