Place video files bg1.mp4 through bg7.mp4 in this directory to use them as background videos for different game levels.

The videos will automatically change as the player progresses through levels:

• bg1.mp4 - Level 0
• bg2.mp4 - Level 1
• bg3.mp4 - Level 2
• bg4.mp4 - Level 3
• bg5.mp4 - Level 4
• bg6.mp4 - Level 5
• bg7.mp4 - Level 6
• bg8.mp4 - Level 7+

If a player reaches level 8 or higher, the game will continue to use bg8.mp4.

The video will automatically be sized and positioned to fit within the Tetris game board area (the inner playfield), maintaining aspect ratio with object-fit: contain. The video will not cover the entire screen - it stays within the game borders.

• MP4 (.mp4)
• WebM (.webm)
• Ogg (.ogg)

If a video file fails to load or is not found, the game will automatically fall back to the procedural shader-based background for that level.

All videos loop continuously and play muted. The level calculation is: level = Math.floor(lines * 0.1), so every 10 lines cleared advances one level.