Core features: - Player ship + AI opponent ships. - 3D rendering via Three.js UMD from CDN. - First-person or top-down view? Choose the best approach for a web page. View choice: Top-down is more accessible and fun on mobile, but first-person feels more immersive. Let's go with **first-person** (or perspective) camera — it gives better depth perception for shooting mechanics. The user wants a complete, single-file HTML document that runs immediately when opened in a browser. It must include inline CSS and JavaScript, using Three.js from a CDN if needed. The game is an air-combat shooter called "Dogfight". Key features: player ship, AI opponent ships, 3D rendering via Three.js UMD, first-person or top-down view (I'll choose first-person for better depth perception), mobile-safe canvas sizing, autoplay animation, no console errors, and it must end with ``. Let me plan the implementation: 1. Use Three.js from a CDN (e.g., cdnjs.com). I need to include the UMD build of three.js for browser use. 2. Create a scene, camera, renderer. 3. Add lighting and fog for atmosphere. 4. Implement player ship as a simple geometric shape (like a cone or custom mesh) that follows mouse movement in 3D space. 5. Implement AI ships that spawn randomly and move toward the player. 6. Add shooting mechanics: when clicking, shoot projectiles from the player's position towards the cursor direction. 7. Add collision detection between bullets and enemy ships, and also between enemies and the player (maybe simple distance checks). 8. Add visual effects like trails or particle explosions for impact. 9. Include a HUD with score, health, and maybe ammo count. 10. Make sure the canvas resizes properly on window resize. 11. Ensure all code is self-contained in one file, no external dependencies besides Three.js UMD. Let me start drafting the HTML structure: - `` - `` - `` with meta tags for viewport, charset, title "Dogfight - Air Combat Shooter" - `