*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:linear-gradient(135deg,#1a1a2e,#16213e,#0f3460);min-height:100vh;color:#fff}#app{display:flex;flex-direction:column;align-items:center;padding:20px;min-height:100vh}#game-canvas{background:linear-gradient(180deg,#2d2d44,#1a1a2e);border-radius:12px;box-shadow:0 8px 32px #0000004d}#ui-container{margin-top:20px;text-align:center}#track-selector h2{margin-bottom:16px;font-weight:500}#track-options{display:flex;gap:16px;justify-content:center;margin-bottom:20px}.track-option{width:120px;height:100px;background:#ffffff1a;border:2px solid transparent;border-radius:8px;cursor:pointer;transition:all .2s ease;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px}.track-option:hover{background:#ffffff26;transform:translateY(-2px)}.track-option.selected{border-color:#4dabf7;background:#4dabf733}.track-option span{font-size:14px}.track-icon{display:flex;align-items:center;justify-content:center}.track-icon svg{width:50px;height:35px}#controls{display:flex;gap:12px;justify-content:center}button{padding:12px 32px;font-size:16px;font-weight:500;border:none;border-radius:8px;cursor:pointer;transition:all .2s ease}#start-btn{background:linear-gradient(135deg,#4dabf7,#228be6);color:#fff}#start-btn:hover{transform:translateY(-2px);box-shadow:0 4px 12px #4dabf766}#start-btn:disabled{opacity:.5;cursor:not-allowed;transform:none}#reset-btn{background:#ffffff1a;color:#fff}#reset-btn:hover{background:#fff3}#undo-btn{background:#ef444433;color:#ef4444;border:1px solid rgba(239,68,68,.3)}#undo-btn:hover{background:#ef44444d}#replay-btn{background:linear-gradient(135deg,#22c55e,#16a34a);color:#fff}#replay-btn:hover{transform:translateY(-2px);box-shadow:0 4px 12px #22c55e66}.custom-option{border:2px dashed rgba(255,255,255,.3)}.custom-option:hover{border-color:#4dabf780}.custom-option.selected{border-style:solid;border-color:#4dabf7}#game-canvas.editing{cursor:crosshair}.editing-hint{color:#94a3b8;font-size:14px;margin-top:8px}@media (max-width: 600px){#app{padding:10px}#track-selector h2{font-size:18px;margin-bottom:12px}#track-options{flex-wrap:wrap;gap:10px}.track-option{width:70px;height:70px;padding:8px}.track-option span{font-size:11px}.track-icon svg{width:35px;height:25px}#controls{flex-wrap:wrap;gap:8px}button{padding:10px 20px;font-size:14px}#ui-container{margin-top:12px}}#game-canvas{touch-action:none}button{touch-action:manipulation}