/* Nút tròn, nền đen mờ */
#toggle-music {
  position: fixed;
  bottom: 20px;
  left: 20px;
  width: 40px;
  height: 40px;
  background: rgba(0, 0, 0, 0.3);
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: white;
  cursor: pointer;
  z-index: 1000;
  transition: background 0.5s ease;
}

#toggle-music:hover {
  background: rgba(0, 0, 0, 0.5);
}

/* Keyframes xoay */
@keyframes rotate {
  from {
    transform: rotate(0deg);
  }

  to {
    transform: rotate(360deg);
  }
}

/* Heart fall (giữ nguyên nếu cần) */
@keyframes fall {
  0% {
    transform: translateY(0);
    opacity: 1;
  }

  100% {
    transform: translateY(100vh);
    opacity: 0;
  }
}

.heart {
  position: fixed;
  color: red;
  font-size: 20px;
  top: -10px;
  z-index: 9999;
  pointer-events: none;
  animation: fall linear infinite;
}