:root{--bg: #0a0a0c;--panel: #141418;--accent: #e94e3c;--text: #cfd2da;--text-dim: #6b7080;--white-key: #f4f5f7;--white-key-shadow: #c4c8d0;--black-key: #1b1d24}*{box-sizing:border-box}html,body{margin:0;height:100%;background:var(--bg);color:var(--text);font-family:Segoe UI,system-ui,-apple-system,sans-serif;overflow:hidden}#app{display:flex;flex-direction:column;height:100%}.toolbar{display:flex;align-items:center;gap:28px;padding:14px 22px;background:linear-gradient(180deg,#16161b,#0d0d10);border-bottom:1px solid #000}.brand{display:flex;flex-direction:column;line-height:1.1}.brand strong{font-size:20px;letter-spacing:2px;text-transform:uppercase}.brand span{font-size:11px;color:var(--text-dim);letter-spacing:1px}.navlink{color:var(--text-dim);font-size:13px;text-decoration:none;margin-right:auto;letter-spacing:.5px}.navlink:hover{color:var(--accent)}.control{display:flex;align-items:center;gap:8px;font-size:13px}.control label{color:var(--text-dim);-webkit-user-select:none;user-select:none;cursor:pointer}input[type=range]{accent-color:var(--accent);width:110px}input[type=checkbox]{accent-color:var(--accent);width:16px;height:16px;cursor:pointer}.btn{background:#1d1f27;color:var(--text);border:1px solid #2b2e38;border-radius:8px;padding:8px 16px;font-size:13px;letter-spacing:1px;text-transform:uppercase;cursor:pointer;transition:all .12s ease}.btn:hover{border-color:#3a3e4a}.btn.is-on{background:var(--accent);border-color:var(--accent);color:#fff;box-shadow:0 0 16px #e94e3c99}.piano-stage{flex:1;display:flex;align-items:flex-end;justify-content:center;padding:0;min-height:0}#piano{width:100%;height:min(60vh,420px)}.piano-keyboard{position:relative;display:flex;width:100%;height:100%;background:#000;border-top:3px solid var(--accent);touch-action:none;-webkit-user-select:none;user-select:none}.piano-key{position:relative;display:flex;align-items:flex-end;justify-content:center;cursor:pointer}.piano-key--white{background:linear-gradient(180deg,var(--white-key) 0%,#e7e9ee 92%,var(--white-key-shadow) 100%);border:1px solid #aeb2bc;border-top:none;border-radius:0 0 5px 5px;box-shadow:inset 0 -6px 8px #0000001f;z-index:1}.piano-key--black{position:absolute;top:0;height:62%;background:linear-gradient(180deg,#2a2d36,#14151b 80%,#000);border:1px solid #000;border-radius:0 0 4px 4px;box-shadow:0 4px 6px #0009,inset 0 -3px 4px #ffffff0f;z-index:2}.piano-key--white.is-active{background:linear-gradient(180deg,#ffd9d2,#f4a99e);box-shadow:inset 0 -4px 10px #e94e3c66,0 0 18px #e94e3c73}.piano-key--black.is-active{background:linear-gradient(180deg,#b23a2d,#7a261d);box-shadow:0 0 18px #e94e3cb3}.key-label{font-size:12px;pointer-events:none;display:none;margin-bottom:14px;padding:2px 0;letter-spacing:.5px}.key-label--computer{font-weight:600}.piano-key--white .key-label{color:#8a8f9c}.piano-key--black .key-label{color:#aeb2bc;margin-bottom:8px}#piano.show-computer-keys .key-label--computer,#piano.show-note-names .key-label--note{display:block}#piano.show-computer-keys.show-note-names .key-label--note{font-size:10px;opacity:.7}.hint{text-align:center;color:var(--text-dim);font-size:12px;padding:8px}