:root{--bg: #0f1115;--panel: #1a1d24;--panel-2: #232733;--text: #e9ecf2;--muted: #9aa3b2;--accent: #3d8bfd;--left: #f59f00;--ok: #51cf66;--bad: #e03131;color-scheme:dark;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}*{box-sizing:border-box}[hidden]{display:none!important}html,body{margin:0;height:100%;background:var(--bg);color:var(--text);overscroll-behavior:none}body{display:flex;flex-direction:column;height:100dvh;padding:env(safe-area-inset-top) env(safe-area-inset-right) 0 env(safe-area-inset-left)}button,input,select{font:inherit;color:inherit}button{background:var(--panel-2);border:1px solid #333a48;border-radius:8px;padding:6px 12px;cursor:pointer;touch-action:manipulation}button:hover{border-color:#4a5366}button.primary{background:var(--accent);border-color:var(--accent);color:#fff;min-width:44px}button.link{background:none;border:none;color:var(--accent);padding:4px 0}.topbar{display:flex;align-items:center;gap:12px;padding:8px 12px;background:var(--panel);border-bottom:1px solid #262b36}.brand{display:flex;align-items:center;gap:8px;font-weight:700;background:none;border:none;padding:4px}.song-title{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--muted)}.pill{border-radius:999px;font-size:14px}.pill.connected{border-color:var(--ok);color:var(--ok)}.pill.error{border-color:var(--bad);color:#ff8787}main{flex:1;min-height:0;display:flex;flex-direction:column}.library{overflow-y:auto;padding:16px;max-width:860px;width:100%;margin:0 auto}.hero h1{font-size:24px;margin:8px 0}.hero p{color:var(--muted);line-height:1.5}kbd{background:var(--panel-2);border-radius:4px;padding:0 5px;border:1px solid #39404f;font-size:.9em}h2{font-size:16px;margin:24px 0 8px;color:var(--muted);text-transform:uppercase;letter-spacing:.06em}.song-list{list-style:none;padding:0;margin:0;display:grid;gap:8px}.song-list li{display:flex;align-items:center;gap:8px}.song-card{flex:1;display:flex;justify-content:space-between;align-items:center;gap:12px;text-align:left;padding:12px 14px;background:var(--panel)}.song-card .meta{color:var(--muted);font-size:13px}.badge{font-size:12px;padding:2px 8px;border-radius:999px;background:var(--panel-2);color:var(--muted);white-space:nowrap}.upload{display:block;border:2px dashed #39404f;border-radius:10px;padding:18px;text-align:center;color:var(--muted);cursor:pointer;margin-bottom:8px}.upload.drag{border-color:var(--accent);color:var(--text)}.upload input{display:none}.error{color:#ff8787}.help{margin:24px 0;color:var(--muted);line-height:1.5}.help summary{cursor:pointer;color:var(--text)}.muted{color:var(--muted);font-size:14px}.practice{flex:1;min-height:0;display:flex;flex-direction:column;position:relative}.sheet{height:clamp(120px,24vh,220px);background:#fdfdfb;overflow-x:auto;overflow-y:hidden;flex-shrink:0}.sheet.hidden{display:none}.sheet-empty{color:#555;text-align:center;padding:16px;margin:0}.stage{flex:1;min-height:0;position:relative}#stage{width:100%;height:100%;display:block;touch-action:none}.banner{position:absolute;top:12px;left:50%;transform:translate(-50%);background:#14161cd9;border:1px solid #333a48;padding:6px 14px;border-radius:999px;font-size:14px;pointer-events:none}.result{position:absolute;inset:0;display:grid;place-items:center;background:#0a0c10b3}.result .card{background:var(--panel);border-radius:14px;padding:20px 24px;text-align:center;min-width:260px}.result .score{font-size:44px;font-weight:800;margin:4px 0}.result .pass{color:var(--ok)}.result .fail{color:var(--left)}.result .actions{display:flex;gap:8px;justify-content:center;margin-top:12px}.progress{height:10px;background:#20242e;position:relative;cursor:pointer;flex-shrink:0}#progress-section{position:absolute;top:0;bottom:0;background:#3d8bfd40}#progress-fill{position:absolute;top:0;bottom:0;left:0;background:var(--accent);width:0}.controls{display:flex;flex-wrap:wrap;align-items:center;gap:8px 12px;padding:8px 12px calc(8px + env(safe-area-inset-bottom));background:var(--panel)}.segmented{display:inline-flex}.segmented button{border-radius:0;margin-left:-1px}.segmented button:first-child{border-radius:8px 0 0 8px}.segmented button:last-child{border-radius:0 8px 8px 0}.segmented button.active{background:var(--accent);border-color:var(--accent);color:#fff}.toggle,.tempo{display:inline-flex;align-items:center;gap:6px;font-size:14px;white-space:nowrap}.tempo input{width:110px}.tempo output{min-width:3.2em}.more{position:relative}.more summary{list-style:none;cursor:pointer;padding:6px 10px;border-radius:8px;background:var(--panel-2);border:1px solid #333a48}.more summary::-webkit-details-marker{display:none}.more-panel{position:absolute;bottom:calc(100% + 8px);right:0;background:var(--panel);border:1px solid #333a48;border-radius:10px;padding:12px;display:grid;gap:10px;z-index:5;min-width:240px}.lesson-btn{margin-left:auto}.lesson-panel{position:absolute;top:0;right:0;bottom:0;width:min(340px,90vw);background:var(--panel);border-left:1px solid #262b36;padding:12px 16px;overflow-y:auto;z-index:10;box-shadow:-8px 0 24px #0006}.lesson-head{display:flex;justify-content:space-between;align-items:center}.lesson-head h3{margin:0}#lesson-steps{padding-left:0;list-style:none;display:grid;gap:6px}#lesson-steps button{width:100%;text-align:left;display:flex;justify-content:space-between;gap:8px}#lesson-steps button.active{border-color:var(--accent)}#lesson-steps .done{color:var(--ok)}@media(max-width:640px){.controls{gap:6px 8px;padding:6px 8px calc(6px + env(safe-area-inset-bottom))}.tempo input{width:80px}.hero h1{font-size:20px}}@media(max-height:500px){.sheet{height:96px}.topbar{padding:4px 10px}}.practice.layout-sheet .stage{order:0;flex:0 0 clamp(110px,26vh,220px)}.practice.layout-sheet .sheet{order:1;flex:1;height:auto;overflow-y:auto}.practice.layout-sheet .progress{order:2}.practice.layout-sheet .controls{order:3}.gate{position:fixed;inset:0;z-index:100;display:grid;place-items:center;background:var(--bg)}.gate-card{display:grid;gap:12px;justify-items:center;background:var(--panel);padding:28px;border-radius:14px;width:min(320px,90vw)}.gate-card h1{margin:0;font-size:22px}.gate-card input{width:100%;padding:10px 12px;border-radius:8px;border:1px solid #39404f;background:var(--panel-2);font-size:18px;text-align:center}.gate-card button{width:100%;padding:10px}