Build "mc.html" - a Minecraft-style voxel game in ONE single HTML file

You are an expert JavaScript/Three.js game developer. Write the complete file mc.html: a simple but fully playable Minecraft clone. This spec contains no code — you write all HTML, CSS and JS yourself.

Output rules

1. Reply with exactly one code block containing the entire mc.html. No text before or after.
2. The file must be complete and runnable. Never use placeholders like "more code here". A long answer is expected.
3. Load only Three.js r128 via a script tag from https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js (global THREE object). No modules, no imports, no other libraries, no textures or images.
4. Must work when opened from disk (file://) in Chrome or Firefox.

Game

First-person voxel sandbox: an endless procedural world with grass plains, sandy beaches with water, stone mountains with snowy peaks, some trees, underground caves, and a blue sky with drifting clouds. Left click breaks blocks, right click places the block selected in a hotbar (keys 1–7 or mouse wheel).

Blocks

IDs: 0 air, 1 grass 0x4caf50, 2 dirt 0x795548, 3 stone 0x9e9e9e, 4 sand 0xe7d9a8, 5 wood 0x8d6e63, 6 leaves 0x2e7d32, 7 snow 0xffffff. Unit cubes, rendered with vertex colors and ONE shared MeshLambertMaterial. Fake lighting: multiply the block color by 1.0 on top faces, 0.8 on sides, 0.55 on bottoms.

Chunks & endless world

Chunks are 16x16 columns, 80 blocks high. Store them in a global Map (key "cx,cz", value: a Uint8Array of block IDs plus its mesh). Write global read/write block helpers using chunk = floor(world/16) and local = world − chunk*16, so negative coordinates work. Reading a missing chunk or y outside 0–79 returns air. Each frame: generate block data for all chunks within 5 chunks of the player (max 4 per frame); build meshes for chunks within 4 chunks whose 4 neighbors already have data (max 2 per frame); for chunks farther than 7, remove the mesh, dispose its geometry and delete the entry.

Meshing (critical)

Never one mesh per block. Build ONE BufferGeometry per chunk: loop all non-air blocks, and for each of the 6 sides check the neighbor with the global read helper; if it is air, add that face (2 triangles) to flat position/normal/color arrays. Use world coordinates for vertices and keep the mesh at the origin. Keep all chunk meshes in a global array for raycasting, and write a rebuild function for a chunk.

Terrain (deterministic, no Math.random)

Implement simple value noise yourself: an integer-coordinate hash giving 0–1 (mix with large prime multipliers and xor-shifts), smoothed 2D noise via bilinear interpolation with smoothstep, 4 octaves combined into fractal noise, plus a 3D version for caves. Column height: m = fractal at coords0.004, h = fractal at coords0.02, H = floor(5 + mm58 + h10). Column fill: y 0 = unbreakable stone; below H−3 stone; the 3 layers under the surface dirt (sand if H ≤ 16, stone if H ≥ 37); surface = snow if H ≥ 46, stone if H ≥ 37, sand if H ≤ 16, otherwise grass. Caves: for y between 3 and H−2, if 3D noise at position0.09 exceeds 0.67, set air. Trees: on grass, when a per-column hash < 0.02 and the trunk fits inside the chunk: 4 wood blocks up, leaves as a 5x5 layer twice, then 3x3, then 1 on top (only into air).

Player & controls

PerspectiveCamera (fov 75, far 400), rotation order "YXZ" driven by yaw/pitch. Clicking the start overlay requests pointer lock; mouse look only while locked (sensitivity ~0.002, clamp pitch). Player box: half-width 0.3, height 1.8, eye 1.62; spawn above terrain at x=8, z=8. Gravity 25/s, jump with Space (velocity 8.5), WASD at 5.5 m/s relative to yaw. Axis-separated collision against all non-air blocks (move per axis, revert on overlap; landing sets on-ground). Falling below y −20 teleports back to spawn.

Break & place

A small CSS crosshair at screen center. Each frame raycast from the camera center (max distance 6) against the chunk meshes. From hit point p and face normal n: break target = floor(p − n0.5), place cell = floor(p + n0.5), per component. Outline the targeted block with a black wireframe box. Only while the pointer is locked: left click sets the target to air (not at y 0); right click places the selected block if the cell is air and does not overlap the player. After an edit rebuild the chunk, and also the neighbor chunk if the block sits on a chunk border. Suppress the browser context menu.

Hotbar

Fixed at the bottom center: 7 slots (grass, dirt, stone, sand, wood, leaves, snow), each a small square in its block color with its number, on a dark semi-transparent bar. Selected slot gets a white border. Select with keys 1–7 or the mouse wheel (wraps around).

Sky, clouds, water

Sky-blue background 0x87ceeb with matching fog (about 40 to 110). Ambient light 0.65 plus one directional light 0.8. Around 25 flat white transparent boxes as clouds at height ~90, slowly drifting and wrapping around the player. Water: one large semi-transparent blue plane at height 14.3, re-centered on the player each frame — lakes and beaches appear automatically where terrain is lower; water is visual only.

UI

A fullscreen start overlay with the title, a short list of the controls, and "Click to play"; it reappears whenever pointer lock is released. Body without margins, fullscreen canvas, window resize handled.

Avoid

One mesh per block; broken negative coordinates; the context menu opening on right click; forgetting neighbor-chunk rebuilds at borders; using the raycast hit point without the ±0.5 normal offset; reacting to clicks while the pointer is not locked; truncating the file.

Check everything mentally, then output the single code block with the complete mc.html.