Tetris · deepseek-v3.1-terminus

We are going to build a Tetris game in a single HTML file with inline CSS and JavaScript.
 The game will have:
   - A canvas for the main game board
   - A preview for the next piece
   - Score display
   - Level (increasing speed) and lines cleared
   - All seven tetrominoes with their colors
   - Rotation, line clears, and increasing speed

 Steps:
 1. Set up the HTML structure with a container for the game, the main canvas, a side panel for next piece, score, level, and lines.
 2. Style the elements with CSS to arrange them appropriately.
 3. Write the JavaScript code for the game logic:
    a. Define the tetromino shapes and colors.
    b. Set up the game board (matrix) and game state.
    c. Draw the game board and the falling piece.
    d. Handle user input for moving and rotating the piece.
    e. Implement the game loop with increasing speed (levels).
    f. Check for line clears and update the score, level, and lines.
    g. Show the next piece preview.

 Let's create the index.html file with all the code.

I've created a complete Tetris game with all the requested features:

**Features included:**
- ✅ All 7 tetromino pieces (I, J, L, O, S, T, Z) with their correct shapes and colors
- ✅ Rotation using the up arrow key
- ✅ Line clearing with scoring
- ✅ Increasing speed based on level (speed increases every 10 lines cleared)
- ✅ Next-piece preview showing the upcoming piece
- ✅ Score tracking with increasing points for multiple line clears
- ✅ Level system (increases every 10 lines)
- ✅ Game over detection
- ✅ Pause functionality (press P)
- ✅ Hard drop (space bar)
- ✅ Smooth controls with arrow keys

**Controls:**
- ← → : Move left/right
- ↑ : Rotate piece
- ↓ : Soft drop (accelerated fall)
- Space : Hard drop (instant fall to bottom)
- P : Pause game

The game is fully self-contained in a single HTML file with no external dependencies. It features a modern dark theme with colored pieces, smooth animations, and a clean interface showing score, level, lines cleared, and next piece preview.

You can open the `index.html` file in any modern web browser to play the game immediately!