/**
 * BGM Style
 */
#bgm-container {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: rgba(0, 0, 0, 0.04);
  padding: 8px 14px;
  border-radius: 30px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  margin: 15px 0 15px 20px;
  transition: all 0.3s ease;
}
#bgm-main-btn {
  background: none;
  border: none;
  padding: 0;
  width: 28px;
  height: 28px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
#bgm-main-btn svg {
  width: 20px;
  height: 20px;
  fill: #444444;
  transition: fill 0.2s, transform 0.2s;
}
#bgm-main-btn:hover svg {
  fill: #000000;
  transform: scale(1.1);
}
.bgm-volume-wrapper {
  display: flex;
  align-items: center;
  width: 60px;
  opacity: 0.4;
  transition: opacity 0.2s;
}
#bgm-container:hover .bgm-volume-wrapper {
  opacity: 1;
}
#bgm-volume {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 3px;
  background: rgba(0, 0, 0, 0.1);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}
#bgm-volume::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #555555;
}
#bgm-volume::-moz-range-thumb {
  width: 10px;
  height: 10px;
  border: none;
  border-radius: 50%;
  background: #555555;
}

/* モバイル対応 */
@media screen and (max-width: 767px) {
  #bgm-container {
    margin: 10px 0 10px 12px;
    padding: 6px 10px;
    gap: 8px;
  }
  #bgm-main-btn {
    width: 22px;
    height: 22px;
  }
  #bgm-main-btn svg {
    width: 16px;
    height: 16px;
  }
  .bgm-volume-wrapper {
    width: 45px;
    opacity: 0.7;
  }
}