This is a one-shot benchmark. Work autonomously and do not ask questions. Create the complete final artifact as index.html in the current empty directory. There will be no second attempt and no feedback-driven corrections. You may test and inspect your own work during this single run. The artifact must open directly in a modern browser without a build step. CDN imports for Three.js are allowed, but do not use external models, textures, images, or other content assets.

Build a complete playable 3D Tetris game using Three.js in a single HTML file.

Pieces must fall into a three-dimensional grid rather than a flat 2D board.

Allow rotation around all three axes.

Completed horizontal planes should disappear.

Add translucent grid visualization, shadows, particle effects when layers disappear, score, next-piece preview and game-over state.

Use OrbitControls so the player can inspect the board from every direction.

Make spatial orientation immediately understandable.