:root{--bg: #f4f5f7;--panel: #ffffff;--ink: #1b1d21;--ink-soft: #5b6068;--line: #d6d9de;--accent: #c0392b;--accent-soft: #e8a49b;--metal: #9aa3ad;--metal-dark: #6b7480;--metal-light: #c7ced6;--piston: #b8bec6;--rod: #7f8893;--crank: #5a626d;--bore: #2a2d33;--combustion: #e25822;--valve-intake: #3a7bd5;--valve-exhaust: #d9534f;--spark: #b58900;--spark-flash: #ffd34d;--stroke-intake: #3a7bd5;--stroke-compression: #e0a020;--stroke-power: #d1452f;--stroke-exhaust: #7a828c}@media(prefers-color-scheme:dark){:root{--bg: #15171c;--panel: #1e2127;--ink: #e7eaef;--ink-soft: #9aa1ac;--line: #2c313a;--accent: #e74c3c;--accent-soft: #7a2c25;--metal: #7e8794;--metal-dark: #4a525d;--metal-light: #aab2bd;--piston: #8f97a2;--rod: #6a727d;--crank: #444b55;--bore: #0d0f12;--combustion: #ff6a33;--valve-intake: #5b9bff;--valve-exhaust: #ff6b66;--spark: #ffd23f;--spark-flash: #fff6c2;--stroke-intake: #5b9bff;--stroke-compression: #f0bb3a;--stroke-power: #ff5e44;--stroke-exhaust: #9aa1ac}}*{box-sizing:border-box}html,body{margin:0;height:100%;background:var(--bg);color:var(--ink);font:15px/1.45 system-ui,-apple-system,Segoe UI,Roboto,sans-serif;-webkit-font-smoothing:antialiased}#app{display:grid;grid-template-columns:1fr 320px;grid-template-rows:auto 1fr;grid-template-areas:"header header" "stage  controls";height:100vh;height:100dvh}.app-header{grid-area:header;padding:12px 20px;border-bottom:1px solid var(--line);background:var(--panel);display:flex;align-items:baseline;flex-wrap:wrap;gap:8px 14px}#mode-switch{margin-left:auto;align-self:center}.segmented{display:inline-flex;border:1px solid var(--line);border-radius:8px;overflow:hidden}.segmented button{border:0;background:var(--panel);color:var(--ink-soft);padding:6px 14px;font-size:13px;cursor:pointer}.segmented button+button{border-left:1px solid var(--line)}.segmented button:hover{color:var(--ink)}.segmented button.active{background:var(--accent);color:#fff}.segmented button.active:hover{color:#fff}.app-header h1{margin:0;font-size:20px;letter-spacing:.5px}.subtitle{margin:0;color:var(--ink-soft);font-size:13px}.stage{grid-area:stage;position:relative;overflow:hidden}#scene{display:block;width:100%;height:100%;touch-action:none}#scene.orbit{cursor:grab}#scene.orbit.orbiting{cursor:grabbing}.controls{grid-area:controls;border-left:1px solid var(--line);background:var(--panel);padding:16px;overflow-y:auto}.control{margin-bottom:18px}.control label{display:flex;justify-content:space-between;font-size:13px;color:var(--ink-soft);margin-bottom:6px}.control label .value{color:var(--ink);font-variant-numeric:tabular-nums;font-weight:600}.control input[type=range]{width:100%;accent-color:var(--accent)}.btn{width:100%;padding:9px 12px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);font-size:14px;cursor:pointer}.btn:hover{border-color:var(--accent)}.btn.active{background:var(--accent);color:#fff;border-color:var(--accent)}.btn-row{display:flex;gap:8px;margin-bottom:14px}.btn-sm{padding:7px 6px;font-size:13px}.btn[type=button]{margin-bottom:14px}.control.is-disabled{opacity:.45}.control input[type=range]:disabled{cursor:not-allowed}.readout{display:grid;grid-template-columns:1fr auto;gap:4px 10px;padding:12px;margin-top:8px;border:1px solid var(--line);border-radius:8px;font-size:13px}.readout .k{color:var(--ink-soft)}.readout .v{text-align:right;font-variant-numeric:tabular-nums;font-weight:600}.section-title{font-size:11px;text-transform:uppercase;letter-spacing:.8px;color:var(--ink-soft);margin:4px 0 10px}@media(max-width:720px){#app{grid-template-columns:1fr;grid-template-rows:auto 1fr auto;grid-template-areas:"header" "stage" "controls"}.controls{border-left:none;border-top:1px solid var(--line);max-height:45vh}}