Loom Weave

Build a tiny browser game called "Loom Weave".

Game spec
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A hand loom where you weave a cloth to match the pattern card. The warp hangs as a hundred vertical threads; each pick you throw, you first choose which shed to open — which subset of warp threads lifts — then throw the shuttle, and the weft that lands shows as a row of coloured threads in the cloth. The pattern card above the loom shows the target cloth as a grid of two yarn colours, and the twist is that your shed choice is constrained: threads are tied to shafts, so lifting one thread lifts every thread sharing its shaft, and a wrong shed drags the wrong colour to the face and puts a flaw in the cloth. Click a shaft lever to toggle it, or press the number keys, or use the arrows plus Enter; then Space throws the shuttle. A live flaw counter and a per-row comparison show which rows match the card, and three flaws ends the run. A finished panel pays by rows matched, flaws avoided and picks used, then the next card is denser and the shafts are more entangled. Combo rows of consecutive perfect picks multiply the payout. Workshop look: warm timber loom frame, taut cream warp with a subtle sheen, saturated wool weft, brass lease sticks, a clacking beater, and a shuttle rattle plus beater thud in WebAudio.

Hard constraints — the game will be embedded in a sandboxed iframe on a static gallery site, and a headless browser will screenshot it:

1. Output exactly ONE self-contained HTML file. All CSS and JS inline. Zero external requests: no CDNs, no external fonts, images, or sounds, no fetch/XHR/WebSocket. Any sound must be synthesized with WebAudio.
2. The iframe sandbox is "allow-scripts allow-pointer-lock" (plus an autoplay permission). So: no localStorage, cookies, or indexedDB (opaque origin — access throws); no popups, window.open, or navigation; no access to the parent page; alert()/prompt()/confirm() are silently blocked.
3. The playfield must be visible within 800 ms of load — that is when the screenshot is taken. No dead white screen. If there is a start screen, make it visually rich.
4. Controls: keyboard AND mouse must both work, plus on-screen touch buttons for phones. Call preventDefault() on game keys (arrows, space) so the page never scrolls.
5. The view is 16:9 and must scale to fill the viewport with no overflow or scrollbars.
6. Show a visible score. If the genre has a losing state, show a game-over screen with a restart (button and a key). Idle/clicker games skip game over but still need clear numeric feedback.
7. If you track a score, report it to the arcade shell so the player's best is remembered between visits: on every score change, call parent.postMessage({ source: "ai-arcade", type: "score", score: <number> }, "*"). It is safe to call it no matter what the parent does with it.
8. Keep it tiny: aim for under 400 lines, 60 fps, no frameworks. That 400-line target does not apply to 3D games — true 3D (a camera and perspective-projected world) or pseudo-3D (projected road/track, depth-sorted sprites) — which need their own software renderer and typically land at 800–1400 lines. The rest of this constraint still binds every game: 60 fps, no frameworks, no external assets, and no padding to reach a length.
9. Difficulty: the arcade shell passes the player's chosen difficulty as a URL query parameter. Read it with new URLSearchParams(location.search).get("difficulty") — the value is "easy", "medium", or "hard" (missing or unknown means "medium"). Make the three levels meaningfully different — speed, lives, enemy pressure, reaction time, whatever fits the genre; clicker/idle games with no losing state use starting resources and upgrade cost curves instead. Show the active level in the HUD. Without the parameter the game must be fully playable at its default (medium) tuning.

Return only the complete HTML file, no commentary.