:root{--bg: #0d1018;--panel: #161b27;--ink: #e7ecf5;--muted: #8a94a8;--accent: #6ad0ff;--line: #283044;--cubie: 64px;--spacing: 76px}*{box-sizing:border-box}html,body{margin:0;height:100%}body{background:radial-gradient(120% 120% at 50% 0%,#141a28 0%,var(--bg) 60%);color:var(--ink);font-family:Segoe UI,system-ui,-apple-system,sans-serif;-webkit-user-select:none;user-select:none;touch-action:none}#app{display:flex;flex-direction:column;align-items:center;min-height:100%;padding:12px;gap:12px}.hud{width:100%;max-width:540px;display:flex;align-items:center;justify-content:space-between;gap:10px}.brand{display:flex;flex-direction:column;line-height:1}.brand h1{margin:0;font-size:30px;letter-spacing:2px;font-weight:800;background:linear-gradient(90deg,#7ad6ff,#b88bff 60%,#ff8fae);-webkit-background-clip:text;background-clip:text;color:transparent}.brand .sub{color:var(--muted);font-size:11px;margin-top:3px;letter-spacing:.5px}.stats{display:flex;gap:8px}.stat{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:6px 10px;min-width:60px;text-align:center}.stat .k{color:var(--muted);font-size:10px;text-transform:uppercase;letter-spacing:1px}.stat .v{font-size:18px;font-weight:700;font-variant-numeric:tabular-nums}.bar{width:100%;max-width:540px;display:flex;align-items:center;justify-content:space-between;gap:8px;flex-wrap:wrap}.seg{display:inline-flex;border:1px solid var(--line);border-radius:999px;overflow:hidden;background:var(--panel)}.seg button{background:transparent;color:var(--muted);border:0;padding:6px 14px;font-size:12px;cursor:pointer;font-weight:600}.seg button.on{background:var(--accent);color:#04121b}.btn{background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:10px;padding:7px 12px;font-size:13px;cursor:pointer}.btn:hover{border-color:var(--accent)}.spin{width:100%;max-width:540px;display:flex;align-items:center;justify-content:center;gap:6px}.spin .cap{color:var(--muted);font-size:11px;margin-right:4px;letter-spacing:.5px}.spin button{width:42px;height:34px;background:var(--panel);border:1px solid var(--line);color:var(--ink);border-radius:9px;font-size:17px;line-height:1;cursor:pointer}.spin button:hover{border-color:var(--accent)}.spin button.on{background:var(--accent);color:#04121b;border-color:var(--accent)}.spin button.stop{font-size:12px;color:var(--muted)}.stage{position:relative;width:100%;max-width:540px;aspect-ratio:1 / 1;display:grid;place-items:center}.scene{position:relative;width:320px;height:320px;perspective:1100px;cursor:grab;display:grid;place-items:center}.scene:active{cursor:grabbing}.cube{grid-area:1 / 1;position:relative;width:var(--cubie);height:var(--cubie);transform-style:preserve-3d;transform:rotateX(-26deg) rotateY(-34deg);transition:transform .08s linear}.numcube{grid-area:1 / 1;width:var(--cubie);height:var(--cubie);transform-style:preserve-3d;pointer-events:none;transition:transform .08s linear;transform:rotateX(-26deg) rotateY(-34deg)}.n3{position:absolute;left:0;top:0;width:var(--cubie);height:var(--cubie);display:grid;place-items:center;color:#06101a;font-weight:800;font-variant-numeric:tabular-nums;text-shadow:0 0 4px rgba(255,255,255,.55),0 1px 2px rgba(255,255,255,.7);transform:translate3d(var(--tx),var(--ty),var(--tz)) rotateY(var(--bry, 0deg)) rotateX(var(--brx, 0deg))}.cubie{position:absolute;width:var(--cubie);height:var(--cubie);transform-style:preserve-3d;left:0;top:0}.face{position:absolute;width:var(--cubie);height:var(--cubie);display:grid;place-items:center;border:1px solid rgba(255,255,255,.1);border-radius:9px;font-weight:800;font-variant-numeric:tabular-nums;color:#06101a;text-shadow:0 1px 0 rgba(255,255,255,.25);backface-visibility:hidden;transition:background .12s ease,opacity .12s ease}.cubie.empty .face{background:#7896c80d;border-color:#7896c81f}.f-front{transform:translateZ(calc(var(--cubie) / 2))}.f-back{transform:rotateY(180deg) translateZ(calc(var(--cubie) / 2))}.f-right{transform:rotateY(90deg) translateZ(calc(var(--cubie) / 2))}.f-left{transform:rotateY(-90deg) translateZ(calc(var(--cubie) / 2))}.f-top{transform:rotateX(90deg) translateZ(calc(var(--cubie) / 2))}.f-bottom{transform:rotateX(-90deg) translateZ(calc(var(--cubie) / 2))}.len2{font-size:26px}.len3{font-size:22px}.len4{font-size:17px}.len5{font-size:14px}.len6{font-size:12px}.scene.ghost .cubie:not(.empty) .face{opacity:.42}.scene.ghost .cubie.empty .face{opacity:.25}@keyframes pop{0%{transform:scale(1)}40%{transform:scale(1.14)}to{transform:scale(1)}}.cubie.pop{animation:pop .18s ease-out}@keyframes spawnpulse{0%{box-shadow:0 0 #78dcff00}30%{box-shadow:0 0 0 4px #78dcff99}to{box-shadow:0 0 #78dcff00}}.cubie.spawn .face{animation:spawnpulse .5s ease-out}.layers{position:absolute;inset:0;display:none;grid-template-columns:repeat(3,1fr);gap:10px;align-content:center;padding:6px;background:#080b12d9;border-radius:14px}.stage.exploded .scene{visibility:hidden}.stage.exploded .layers{display:grid}.layer{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:8px}.layer h4{margin:0 0 6px;font-size:10px;color:var(--muted);text-align:center;text-transform:uppercase;letter-spacing:1px}.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:5px}.cell2{aspect-ratio:1/1;border-radius:8px;display:grid;place-items:center;font-weight:800;font-variant-numeric:tabular-nums;color:#06101a;background:#7896c80f}.pad{display:grid;grid-template-columns:repeat(3,44px);grid-auto-rows:38px;gap:6px;justify-content:center}.pad button{background:var(--panel);border:1px solid var(--line);color:var(--ink);border-radius:9px;font-size:16px;cursor:pointer}.pad button:hover{border-color:var(--accent)}.pad .z{color:var(--accent)}.hint{color:var(--muted);font-size:11px;text-align:center;max-width:540px;line-height:1.5}.hint b{color:var(--ink)}.over{position:absolute;inset:0;display:none;place-items:center;background:#080b12d1;border-radius:14px}.stage.over .over{display:grid}.over .card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:22px 26px;text-align:center}.over .card h2{margin:0 0 6px}.over .big{font-size:40px;font-weight:800;margin:8px 0;background:linear-gradient(90deg,#7ad6ff,#ff8fae);-webkit-background-clip:text;background-clip:text;color:transparent}.over .row{color:var(--muted);font-size:13px;margin:2px 0}@keyframes hlpulse{0%,to{box-shadow:0 0 8px 1px #ffffff73}50%{box-shadow:0 0 16px 4px #ffffffd9}}.cubie.hl .face{outline:2px solid #fff;animation:hlpulse 1.2s ease-in-out infinite}.help-ov{position:fixed;inset:0;z-index:50;background:#06090fb8;backdrop-filter:blur(3px);display:grid;place-items:start center;overflow:auto;padding:24px 14px}.help-modal{position:relative;width:100%;max-width:600px;background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:22px 24px 26px;box-shadow:0 24px 60px #00000080}.help-modal h2{margin:0 0 6px;font-size:24px}.help-modal .hl-name{background:linear-gradient(90deg,#7ad6ff,#b88bff 60%,#ff8fae);-webkit-background-clip:text;background-clip:text;color:transparent}.help-modal .lead{color:var(--muted);margin:0 0 16px;line-height:1.5}.help-modal h3{font-size:14px;margin:18px 0 6px}.help-modal p,.help-modal li{font-size:13px;line-height:1.5;color:var(--ink)}.help-modal b{color:#fff}.help-x{position:absolute;top:14px;right:14px;width:30px;height:30px;border-radius:8px;background:transparent;color:var(--muted);border:1px solid var(--line);cursor:pointer;font-size:14px}.help-x:hover{color:var(--ink);border-color:var(--accent)}.help-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px 18px;margin:4px 0 8px}.help-grid h3{margin:0 0 2px}.help-grid p{margin:0;color:var(--muted)}.help-grid b{color:var(--ink)}.demo-h{border-top:1px solid var(--line);padding-top:16px}.demo-lead{color:var(--muted);margin:0 0 10px}.help-demo{display:flex;flex-direction:column;align-items:center;gap:6px;background:#080b1280;border:1px solid var(--line);border-radius:14px;padding:12px 14px}.help-scene{position:relative;width:260px;height:222px;perspective:1000px;cursor:grab;touch-action:none;overflow:hidden;border-radius:12px;display:grid;place-items:center}.help-scene:active{cursor:grabbing}.help-cap{width:100%;text-align:center}.help-cap h4{margin:2px 0 6px;font-size:15px;color:var(--accent)}.help-cap p{margin:0 auto 10px;color:var(--ink);max-width:460px}.help-steps{display:flex;align-items:center;justify-content:center;gap:10px}.help-steps #help-ind{color:var(--muted);font-size:12px;font-variant-numeric:tabular-nums}.help-steps .btn:disabled{opacity:.4;cursor:default}.help-controls{margin:6px 0 0;padding-left:18px}.help-controls li{color:var(--muted);margin:2px 0}.help-controls b{color:var(--ink)}@media(max-width:540px){.help-grid,.help-demo{grid-template-columns:1fr}.help-scene{margin:0 auto}}@media(max-width:420px){.scene{transform:scale(.84)}.brand h1{font-size:26px}}