Markdown Viewer Enhanced

A browser extension that elegantly renders Markdown files with a file browser sidebar, Mermaid diagrams, syntax highlighting, KaTeX math formulas, table of contents navigation, multiple themes, and more.

## ✨ Key Features

- 📁 **File Browser** — Local file directory tree, folder expand/collapse, open files in new tab, breadcrumb navigation
- 🎨 **Multiple Themes** — Light / Dark / Auto (follows system), 15 code highlight themes (including auto)
- 📊 **Mermaid Diagrams** — Flowcharts, sequence diagrams, Gantt charts with click-to-zoom, drag & pan, keyboard shortcuts
- 🌱 **PlantUML Diagrams** — UML class, sequence, activity diagrams via online PlantUML server, click to zoom in lightbox
- 🔗 **Graphviz Diagrams** — DOT language graph rendering via local Viz.js engine, click to zoom with scale control bar
- 💻 **Syntax Highlighting** — Powered by highlight.js, 180+ languages, line numbers, one-click copy, diff syntax highlighting
- 🔢 **KaTeX Math** — Inline `$...$` and block `$$...$$` LaTeX formula rendering with placeholder protection
- 📑 **TOC Navigation** — Auto-generated heading tree with fold/expand, keyword search & filter, left/right sidebar, scroll tracking, URL hash navigation
- 📐 **Typography** — Font size, line height, content width, font family customization, sidebar drag-to-resize
- 🖼️ **Image Lightbox** — Click to zoom, scroll-wheel zoom (0.1x–20x), drag to pan, double-click reset, keyboard shortcuts (`+`/`-`/`0`/`R`/`Esc`), zoom percentage indicator
- 📝 **Extended Syntax** — GitHub alerts (including `[!BLANK]`), task lists, footnotes, definition lists, enhanced tables, `==highlight==`, `^superscript^`, `~subscript~`, `++underline++`, `:emoji:` GitHub-style emoji, `{color:xxx}text{/color}` inline colored text
- 📄 **YAML Front Matter** — `.mdc` files with YAML front matter header are rendered with styled metadata display
- ⚙️ **Settings System** — Popup quick panel + Options advanced page, real-time push to all tabs
- 🔄 **File Change Detection** — Auto-detect source file changes with "File updated" badge, click to reload
- 🌐 **Multi-language** — Chinese and English interface, switchable in settings

## 📋 Supported File Formats

| Extension | Description |
|-----------|-------------|
| `.md` | Markdown file |
| `.mdc` | Markdown component file |
| `.markdown` | Markdown file |
| `.mkd` | Markdown file |
| `.mdown` | Markdown file |
| `.mdtxt` | Markdown text file |
| `.mdtext` | Markdown text file |

## Accessing Local Files

To render local Markdown files, enable file access for the extension:

1. Go to your browser's extension management page
2. Find **Markdown Viewer Enhanced**
3. Click "Details" → Enable "Allow access to file URLs"