#canvas-container {
    position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
    border-radius: 16px; background: rgba(255,255,255,0.25);
    touch-action: none; overflow: hidden; border: 1.5px solid rgba(255,255,255,0.25);
    box-shadow: 0 40px 100px -20px rgba(0,0,0,0.20), inset 0 1px 0 rgba(255,255,255,0.6);
}
canvas { display: block; touch-action: none; border-radius: 16px; }