:root{color-scheme:dark;--bg-top: #07111e;--bg-bottom: #02060d;--panel: rgba(9, 18, 31, .78);--panel-border: rgba(143, 196, 255, .18);--panel-shadow: 0 24px 60px rgba(0, 0, 0, .35);--text-main: #eef4ff;--text-muted: #9fb4d4;--accent: #ffd35a;--accent-alt: #53d39d;--danger: #ff8478;--surface: rgba(255, 255, 255, .06);--surface-strong: rgba(255, 255, 255, .12);--focus: #8ac4ff;--radius-xl: 28px;--radius-lg: 20px;--radius-md: 14px;--font-display: "Avenir Next", "Trebuchet MS", sans-serif}*{box-sizing:border-box}html,body{margin:0;min-height:100%}body{min-height:100vh;font-family:var(--font-display);color:var(--text-main);background:radial-gradient(circle at top left,rgba(69,119,255,.22),transparent 30%),radial-gradient(circle at bottom right,rgba(54,212,152,.18),transparent 28%),linear-gradient(180deg,var(--bg-top),var(--bg-bottom))}button,input,textarea,select{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.55}button:focus-visible{outline:3px solid var(--focus);outline-offset:3px}.app-shell{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(300px,380px);height:100dvh;min-height:100vh;gap:20px;padding:20px;overflow:hidden}.scene-panel,.control-panel{min-height:0}.scene-panel{position:relative;display:flex;flex-direction:column;overflow:hidden;border:1px solid var(--panel-border);border-radius:var(--radius-xl);background:#060c1673;box-shadow:var(--panel-shadow)}.scene-panel:after{position:absolute;inset:auto 24px 24px auto;width:160px;height:160px;border-radius:999px;background:radial-gradient(circle,rgba(255,211,90,.18),transparent 65%);content:"";pointer-events:none}.scene-stage{position:relative;display:flex;flex:1;min-height:0}.scene-copy{position:absolute;top:24px;left:24px;z-index:1;max-width:360px;padding:18px 20px;border:1px solid rgba(255,255,255,.12);border-radius:var(--radius-lg);background:#040a128f;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.scene-copy h1,.panel-intro h2{margin:0;font-size:clamp(1.8rem,2.6vw,3rem);line-height:.96;letter-spacing:-.04em}.scene-description,.panel-intro p,.status-copy,.empty-copy{color:var(--text-muted);line-height:1.55}.eyebrow{margin:0 0 12px;color:var(--accent);font-size:.78rem;letter-spacing:.24em;text-transform:uppercase}#container3D{flex:1;min-height:0;touch-action:none}#container3D canvas{display:block;width:100%;height:100%}.layer-arrow-overlay{position:absolute;inset:0;z-index:2;pointer-events:none}.layer-arrow-grid{position:absolute;inset:0}.layer-arrow-empty,.layer-arrow-caption{position:absolute;left:50%;max-width:min(86%,520px);padding:12px 16px;border:1px solid rgba(255,255,255,.14);border-radius:var(--radius-md);background:#040a12b8;color:var(--text-muted);text-align:center;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.layer-arrow-empty{top:50%;display:grid;gap:6px;transform:translate(-50%,-50%)}.layer-arrow-empty strong,.layer-arrow-caption strong{color:var(--text-main)}.layer-arrow-caption{display:inline-grid;gap:4px;transform:translate(-50%)}.layer-arrow-caption[data-locked=true]{border-color:#ffd35a61}.layer-arrow-button{position:absolute;left:0;top:0;width:clamp(56px,7.5vw,88px);height:clamp(56px,7.5vw,88px);border:1px solid rgba(255,255,255,.24);border-radius:999px;background:#060c16c2;box-shadow:0 16px 32px #01040c5c;color:var(--text-main);font-size:clamp(1.8rem,4vw,3rem);line-height:1;pointer-events:auto;transform:translate(-50%,-50%);transition:translate .16s ease,scale .16s ease,border-color .16s ease,background .16s ease,color .16s ease}.layer-arrow-button:hover:not(:disabled){translate:0 -2px;scale:1.03;border-color:#ffd35a8a;background:#ffd35a2e;color:var(--accent)}.control-panel{display:grid;gap:14px;align-content:start;overflow:auto;padding-right:4px}.panel-section{padding:16px 18px;border:1px solid var(--panel-border);border-radius:var(--radius-lg);background:var(--panel);box-shadow:var(--panel-shadow);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.panel-section h3{margin:0 0 12px;font-size:1rem;letter-spacing:.04em;text-transform:uppercase}.panel-intro h2{font-size:clamp(1.45rem,1.8vw,2rem)}.panel-intro p{margin-bottom:0}.face-grid,.utility-grid{display:grid;gap:10px}.face-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.utility-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.direction-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.mode-toggle{display:grid;gap:10px}.mode-option{position:relative;display:grid;gap:6px;padding:14px 16px;border:1px solid rgba(255,255,255,.12);border-radius:var(--radius-md);background:var(--surface);transition:transform .16s ease,border-color .16s ease,background .16s ease}.mode-option:hover{transform:translateY(-2px);border-color:#ffffff38;background:var(--surface-strong)}.mode-option[data-selected=true]{border-color:#ffd35a6b;background:#ffd35a1f}.mode-option input{position:absolute;inset:0;opacity:0}.mode-option__title{color:var(--text-main);font-weight:600}.mode-option__copy{color:var(--text-muted);font-size:.86rem;line-height:1.45}.control-button,.face-button,.direction-button{min-height:48px;padding:12px 14px;border:1px solid rgba(255,255,255,.12);border-radius:var(--radius-md);color:var(--text-main);background:var(--surface);transition:transform .16s ease,border-color .16s ease,background .16s ease}.control-button{text-align:center}.control-button:hover:not(:disabled),.face-button:hover:not(:disabled),.direction-button:hover:not(:disabled){transform:translateY(-2px);border-color:#ffffff47;background:var(--surface-strong)}.face-button{display:inline-flex;align-items:center;justify-content:flex-start;gap:12px;text-align:left}.face-text{display:grid;gap:2px}.face-swatch{width:14px;height:14px;border-radius:999px;background:var(--face-button-color, rgba(255, 255, 255, .4));box-shadow:0 0 0 2px #ffffff2e;flex:0 0 auto}.face-label{font-weight:600}.face-copy{color:var(--text-muted);font-size:.78rem;line-height:1.35}.face-button[data-selected=true]{border-color:color-mix(in srgb,var(--face-button-color, #fff) 62%,white 38%);background:var(--face-button-tint, rgba(255, 255, 255, .14));color:var(--text-main);box-shadow:inset 0 0 0 1px #ffffff14}.direction-button{min-height:56px;text-align:left}.direction-title{display:block;margin-bottom:4px;font-size:1rem;font-weight:600}.direction-copy{display:block;color:var(--text-muted);font-size:.85rem;line-height:1.45}.control-button[data-action=solve]{border-color:#53d39d66;background:#53d39d29}.control-button[data-action=moves]{border-color:#8ac4ff61;background:#8ac4ff1f}.control-button[data-action=revert]{border-color:#ffd35a66;background:#ffd35a1f}.control-button[data-action=stop]{border-color:#ff847866;background:#ff847824}.control-button--compact{min-width:58px;min-height:46px;padding:10px 12px;font-size:1.2rem;font-weight:700}.zoom-strip,.move-plan{margin-top:14px;padding:12px 14px;border-radius:var(--radius-md);background:#ffffff0d}.zoom-strip{display:grid;gap:12px}.zoom-label{display:inline-flex;align-items:center;width:fit-content;padding:4px 10px;border-radius:999px;background:#ffffff14;color:#dceeff;font-size:.82rem;letter-spacing:.08em;text-transform:uppercase}.zoom-buttons{display:inline-flex;gap:10px}.zoom-copy{margin:0;color:var(--text-muted);line-height:1.5}.move-plan{display:grid;gap:10px}.move-plan-header,.status-row{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}.move-plan-title,.status-meta{color:#dceeff;font-size:.92rem}.move-plan-copy{margin:0;font-family:SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;color:var(--text-main);line-height:1.7;word-break:break-word}.move-plan-list{display:grid;gap:10px;margin:0;padding:0;list-style:none}.move-plan-step{display:grid;grid-template-columns:auto minmax(0,1fr);gap:10px;align-items:start;padding:10px 12px;border-radius:12px;background:#ffffff0a}.move-plan-step-number{display:inline-flex;align-items:center;justify-content:center;min-width:28px;min-height:28px;border-radius:999px;background:#8ac4ff29;color:#dceeff;font-size:.82rem;font-weight:700}.move-plan-step-body{display:grid;gap:6px}.move-plan-step-copy{color:var(--text-main);line-height:1.5}.move-plan-step-notation{width:fit-content;padding:2px 8px;border-radius:999px;background:#ffffff14;color:var(--text-muted);font-family:SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;font-size:.78rem}.status-block{margin-top:14px;padding:12px 14px;border-radius:var(--radius-md);background:#ffffff0d}.status-label{display:inline-flex;align-items:center;margin-bottom:8px;padding:4px 10px;border-radius:999px;background:#8ac4ff24;color:#dceeff;font-size:.82rem;letter-spacing:.08em;text-transform:uppercase}.status-copy,.empty-copy{margin:0}@media(max-width:1080px){.app-shell{height:auto;grid-template-columns:1fr;gap:18px;padding:18px;overflow:visible}.scene-panel{min-height:56vh}.scene-copy{position:relative;top:0;left:0;margin:20px;max-width:none}.control-panel{overflow:visible;padding-right:0}}@media(max-width:640px){.app-shell{padding:16px;gap:16px}.scene-copy,.panel-section{padding:16px}.face-grid,.utility-grid,.direction-grid{grid-template-columns:1fr}}