/* css/sound-umbral.css */
#sound-toggle {
  position: fixed;
  top: 25%;
  left: 50%;
  transform: translateX(-50%);
  width: 10rem;
  height: 10rem;
  border-radius: 50%;
  border: none;
  background: rgba(234, 247, 224, 0.12);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 0 40px rgba(0,0,0,0.3), inset 0 0 60px rgba(234,247,224,0.05);
  color: rgba(255,255,255,0.9);
  font-family: 'Inter', 'Segoe UI', system-ui, sans-serif;
  font-weight: 500;
  font-size: 1.1rem;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  text-transform: uppercase;
  user-select: none;
}

#sound-toggle:hover {
  background: rgba(234, 247, 224, 0.2);
  transform: translateX(-50%) scale(1.05);
  box-shadow: 0 0 60px rgba(234,247,224,0.15);
}

#sound-toggle:active {
  transform: translateX(-50%) scale(0.95);
}

#sound-toggle.playing {
  color: #ff6b6b;
  background: rgba(255, 107, 107, 0.15);
  box-shadow: 0 0 60px rgba(255,107,107,0.2);
  animation: pulse-sound 1.2s ease-in-out infinite;
}

#sound-toggle.playing:hover {
  background: rgba(255, 107, 107, 0.25);
}

#sound-toggle.inactive {
  opacity: 0.4;
  pointer-events: none;
}

@keyframes pulse-sound {
  0% { box-shadow: 0 0 40px rgba(255,107,107,0.15); }
  50% { box-shadow: 0 0 80px rgba(255,107,107,0.35); }
  100% { box-shadow: 0 0 40px rgba(255,107,107,0.15); }
}

#sound-toggle .icon {
  display: inline-block;
  margin-right: 6px;
  font-size: 1.6rem;
  line-height: 1;
}

#sound-toggle.playing .icon {
  animation: spin-icon 3s linear infinite;
}

@keyframes spin-icon {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Responsive */
@media (max-width: 768px) {
  #sound-toggle {
    width: 7rem;
    height: 7rem;
    font-size: 0.85rem;
    top: 20%;
  }
  #sound-toggle .icon {
    font-size: 1.2rem;
  }
}