.fun-sound-toggle {
  position: fixed;
  right: 16px;
  bottom: 18px;
  z-index: 80;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel);
  color: var(--text);
  box-shadow: 0 8px 28px rgba(0, 0, 0, .24);
  font-size: 18px;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.fun-sound-toggle:active { transform: scale(.94); }

.fun-particle {
  position: fixed;
  z-index: 110;
  pointer-events: none;
  font-size: 20px;
  animation: fun-pop 1.05s cubic-bezier(.18, .75, .25, 1) forwards;
  transform: translate(-50%, -50%);
}

@keyframes fun-pop {
  0% { opacity: 0; transform: translate(-50%, -30%) scale(.4); }
  18% { opacity: 1; }
  100% { opacity: 0; transform: translate(calc(-50% + var(--dx)), calc(-50% + var(--dy))) rotate(var(--rot)) scale(1.1); }
}

@media(max-width: 420px) {
  .fun-sound-toggle { right: 12px; bottom: 12px; }
}

@media(prefers-reduced-motion: reduce) {
  .fun-particle { animation: none !important; display: none !important; }
}