单文件 WebGL2 体素生存沙盒：合成、生物与昼夜循环

Build a browser sandbox game in the spirit of Minecraft that feels as close to the original as possible. All in-game text in English. Controls: keyboard and mouse (desktop).  TECH - A single HTML file, plain WebGL2, no third-party libraries. - All 16×16 textures generated in code as pixel art (stone, dirt, grass, planks, leaves, ores, glass, water, lava, etc.). - Sounds synthesized with WebAudio: digging, footsteps, placing blocks, damage, mobs, explosions, calm background music.  WORLD - Infinite world made of 16×16×128 chunks, with a seed. - Biomes: plains, forest, birch forest, taiga, snowy tundra, desert, mountains, oceans, beaches. - Caves (winding tunnels and large caverns), lava at the lower levels, ores by depth: coal, iron, gold, diamonds. - Three tree types, tall grass, flowers, cacti, sugar cane, pumpkins. - Minecraft-style lighting: sky light and block light (torches, glowstone, lava) that spreads cell by cell, with smooth lighting and ambient occlusion. - Day/night cycle: sun, moon, stars, sunsets, 3D clouds, distance fog, rain. - Water and lava flow by levels; two sources make infinite water; water + lava make obsidian or cobblestone. Sand and gravel fall.  PLAYER - First person, collisions, jumping, sprinting, sneaking (doesn't fall off edges), swimming, ladders, fall damage. - Block breaking with crack stages and particles; break time depends on the tool. - Visible hand and held item with a swing animation. Third-person view on F5.  SURVIVAL - Health, hunger, saturation, air underwater. - Tools in 5 materials with durability, armor in 4 materials. - Inventory with 2×2 crafting, 3×3 crafting table, furnace with fuel, chests, bed (skip the night and set spawn). - Item drops, death and respawn. - Mobs: pigs, cows, sheep, chickens (breeding, shearing); at night zombies, skeletons with bows, spiders. Zombies and skeletons burn in sunlight. - Farming: hoe, seeds, wheat growth, bread. Doors, fences, fence gates, TNT.  CREATIVE - Flying on double-tap Space, instant block breaking, a catalog of all blocks with tabs and search.  UI - Title screen with a world panorama, world list (create / delete / play), options (FOV, render distance, sensitivity, sound, brightness, GUI scale). - Pause menu, death screen, HUD (hotbar, hearts, hunger, armor, air bubbles), F3 debug screen. - Chat with commands: /gamemode, /time, /give, /tp, /summon, /weather. - Worlds saved in localStorage.  RESTRICTIONS - Do not use Minecraft's name, logo, textures or characters (Steve, Creeper, etc.): give the game its own name and design your own mobs.  TESTING - Run the game in a headless browser, check every system and fix bugs before delivering.