.sound-toggle {
  appearance: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 20px;
  padding: 0;
  border: 0;
  background: transparent;
  color: #fff;
  font: inherit;
  letter-spacing: inherit;
  text-shadow: 2px 2px 0 rgba(0,0,0,0.18);
  cursor: pointer;
}

.sound-toggle:hover {
  transform: translate(-1px, -1px);
  color: #fff8d4;
}

.sound-toggle.is-off {
  opacity: 0.62;
}

.sound-meter {
  display: inline-flex;
  align-items: flex-end;
  gap: 2px;
  width: 14px;
  height: 12px;
}

.sound-meter span {
  display: block;
  width: 2px;
  height: 3px;
  background: currentColor;
  box-shadow: 1px 1px 0 rgba(0,0,0,0.28);
}

.sound-toggle.is-on .sound-meter span {
  animation: sound-meter 0.72s steps(2, end) infinite;
}

.sound-toggle.is-on .sound-meter span:nth-child(1) {
  height: 5px;
  animation-delay: 0s;
}

.sound-toggle.is-on .sound-meter span:nth-child(2) {
  height: 9px;
  animation-delay: 0.12s;
}

.sound-toggle.is-on .sound-meter span:nth-child(3) {
  height: 7px;
  animation-delay: 0.24s;
}

.sound-toggle.is-on .sound-meter span:nth-child(4) {
  height: 11px;
  animation-delay: 0.36s;
}

.sound-toggle.is-off .sound-meter span {
  height: 3px;
  animation: none;
}

@keyframes sound-meter {
  0% { transform: scaleY(0.45); }
  50% { transform: scaleY(1); }
  100% { transform: scaleY(0.62); }
}