2048 · glm-4.7

The user wants me to build a playable 2048 game in a single HTML file with:
- Arrow-key tile sliding and merging
- Smooth animations
- A score display
- Win and lose states

I'll create a complete, self-contained index.html file with all CSS and JavaScript inline. No external resources or CDNs.

Let me plan the implementation:

1. HTML structure:
   - Game board (4x4 grid)
   - Score display
   - New game button
   - Win/lose overlay messages

2. CSS:
   - Grid layout for the board
   - Tile colors based on values
   - Smooth animations for sliding and merging
   - Responsive design

3. JavaScript:
   - Game state management (4x4 array)
   - Move logic for all 4 directions
   - Tile merging logic
   - Random tile spawning (2 or 4)
   - Win detection (2048 tile)
   - Lose detection (no valid moves)
   - Score tracking
   - Animation handling

Let me write this all in one file.

I'll create a complete 2048 game with all the features you requested. Let me build this in a single HTML file.

I've created the complete 2048 game. Let me verify the file was created correctly and summarize what I built.

I've created a fully playable 2048 game in `index.html`. Here's what's included: **Features:** - **Arrow key controls** - Use ↑↓←→ to slide tiles - **Smooth animations** - Tiles slide smoothly, new tiles pop in, merged tiles pulse - **Score tracking** - Current score and best score (saved to localStorage) - **Win state** - Shows "You Win!" when you reach 2048, with "Keep Playing" option - **Lose state** - Shows "Game Over!" when no moves remain - **New Game button** - Start fresh anytime **Technical details:** - Complete game logic: tile movement, merging, random spawning (2 or 4) - Responsive design - works on desktop and mobile - Mobile controls - on-screen buttons + touch swipe support - Color-coded tiles from 2 to 2048+ with proper styling - All CSS and JavaScript inline in a single file - No external dependencies or network requests The game runs entirely sandboxed with smooth CSS transitions for tile movement (0.15s ease-in-out) and animations for new/merged tiles.