/* ============================================
   声音开关按钮（全站浮动）
   ============================================ */

.audio-toggle {
  position: fixed;
  top: 22px;
  right: 22px;
  z-index: 999;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--c-gold);
  background: rgba(245, 235, 215, 0.85);
  color: var(--c-ink);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s;
  backdrop-filter: blur(4px);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.12);
}

.audio-toggle:hover {
  background: var(--c-paper-light);
  border-color: var(--c-gold-light);
  box-shadow: 0 0 12px rgba(201, 169, 110, 0.6);
}

.audio-toggle svg {
  width: 22px;
  height: 22px;
  stroke: var(--c-ink);
  fill: none;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* 声波（开启状态显示） */
.audio-toggle .wave {
  opacity: 1;
  transition: opacity 0.25s;
}

/* 斜杠（静音状态显示） */
.audio-toggle .slash {
  opacity: 0;
  stroke: var(--c-seal);
  transition: opacity 0.25s;
}

.audio-toggle.muted .wave { opacity: 0; }
.audio-toggle.muted .slash { opacity: 1; }
.audio-toggle.muted { border-color: rgba(184, 145, 90, 0.5); }