diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1,7 +1,104 @@
 # TNT
 
-TNT's Not Tunnel - A lightweight terminal chat server
+**TNT's Not Tunnel** - A lightweight terminal chat server written in C
 
-## Work in Progress
+![License](https://img.shields.io/badge/license-MIT-blue.svg)
+![Language](https://img.shields.io/badge/language-C-blue.svg)
 
-This project is under active development.
+## Features
+
+- ✨ **Vim-style operations** - INSERT/NORMAL/COMMAND modes
+- 📜 **Message history** - Browse with j/k keys
+- 🕐 **Full timestamps** - Year-month-day hour:minute with timezone
+- 📖 **Bilingual help** - Press ? for Chinese/English help
+- 🌏 **UTF-8 support** - Full support for Chinese, Japanese, Korean
+- 📦 **Single binary** - Lightweight ~50KB executable
+- 🚀 **Telnet access** - No client installation needed
+- 💾 **Message persistence** - All messages saved to log file
+- ⚡ **Low resource usage** - Minimal memory and CPU
+
+## Building
+
+```bash
+make
+```
+
+For debug build:
+```bash
+make debug
+```
+
+## Running
+
+```bash
+./tnt
+```
+
+Connect from another terminal:
+```bash
+telnet localhost 2222
+```
+
+## Usage
+
+### Operating Modes
+
+- **INSERT** - Type and send messages (default)
+- **NORMAL** - Browse message history
+- **COMMAND** - Execute commands
+
+### Keyboard Shortcuts
+
+#### INSERT Mode
+- `ESC` - Enter NORMAL mode
+- `Enter` - Send message
+- `Backspace` - Delete character
+- `Ctrl+C` - Exit
+
+#### NORMAL Mode
+- `i` - Return to INSERT mode
+- `:` - Enter COMMAND mode
+- `j` - Scroll down (older messages)
+- `k` - Scroll up (newer messages)
+- `g` - Jump to top
+- `G` - Jump to bottom
+- `?` - Show help
+- `Ctrl+C` - Exit
+
+#### COMMAND Mode
+- `Enter` - Execute command
+- `ESC` - Cancel, return to NORMAL
+- `Backspace` - Delete character
+
+### Available Commands
+
+- `list`, `users`, `who` - Show online users
+- `help`, `commands` - Show available commands
+- `clear`, `cls` - Clear command output
+
+## Architecture
+
+- **Network**: Multi-threaded TCP server
+- **TUI**: ANSI escape sequences
+- **Storage**: Append-only log file
+- **Concurrency**: pthread + rwlock
+
+## Configuration
+
+Set port via environment variable:
+
+```bash
+PORT=3333 ./tnt
+```
+
+## Technical Details
+
+- Written in C11
+- POSIX-compliant
+- Thread-safe operations
+- Proper UTF-8 handling for CJK characters
+- Box-drawing characters for UI
+
+## License
+
+MIT License - see LICENSE file