.music-btn {
  position: fixed; bottom: 2rem; right: 2rem; z-index: 9000;
  display: flex; align-items: center; gap: 0.6rem;
  padding: 0.65rem 1.1rem;
  background: rgba(3,3,3,0.85); border: 1px solid var(--border2);
  backdrop-filter: blur(12px); cursor: none;
  transition: border-color 0.3s, background 0.3s, box-shadow 0.3s;
}
.music-btn:hover { border-color: var(--accent); box-shadow: 0 0 20px rgba(0,255,209,0.15); }
.music-btn__bars { display: flex; align-items: flex-end; gap: 2px; height: 14px; }
.music-btn__bars span { display: block; width: 2px; background: var(--accent); border-radius: 1px; animation: bar-dance 0.8s ease-in-out infinite alternate; }
.music-btn__bars span:nth-child(1) { height: 6px; animation-delay: 0s; animation-duration: 0.7s; }
.music-btn__bars span:nth-child(2) { height: 12px; animation-delay: 0.1s; animation-duration: 0.9s; }
.music-btn__bars span:nth-child(3) { height: 8px; animation-delay: 0.15s; animation-duration: 0.6s; }
.music-btn__bars span:nth-child(4) { height: 14px; animation-delay: 0.05s; animation-duration: 0.8s; }
@keyframes bar-dance { from { transform: scaleY(0.3); } to { transform: scaleY(1); } }
.music-btn.is-off .music-btn__bars span { animation: none; transform: scaleY(0.25); background: var(--dimmer); }
.music-btn.is-off { border-color: var(--border); }
.music-btn__lbl { font-family: var(--f-mono); font-size: 0.58rem; letter-spacing: 0.15em; color: var(--accent); transition: color 0.2s; }
.music-btn.is-off .music-btn__lbl { color: var(--dimmer); }
.music-btn.is-off .music-btn__lbl::after { content: ' OFF'; }
@media (max-width: 768px), (hover: none) {
  .music-btn { display: none; }
}