body, html {
    margin: 0; padding: 0; width: 100%; height: 100%;
    overflow: hidden; background-color: #000; touch-action: none;
}

#ui-layer {
    position: absolute; top: 20px; width: 100%;
    display: flex; flex-direction: column; align-items: center;
    gap: 15px; pointer-events: none; z-index: 10;
}

#instruction { color: white; font-family: sans-serif; opacity: 0.6; }

.color-picker {
    display: flex; gap: 15px; pointer-events: auto; /* 버튼은 터치 가능하게 */
}

.color-btn {
    width: 60px; height: 60px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: 2rem; cursor: pointer; background: rgba(255,255,255,0.1);
    border: 3px solid rgba(255,255,255,0.3); transition: 0.2s;
}

.color-btn.active {
    transform: scale(1.2); border-color: white; background: rgba(255,255,255,0.3);
}