/* bgm.css — 右上角悬浮静音按钮（WoW 金色风格） */
/* 浮在 52px topbar 下方（top:64px），不挡导航；z-index 极高避免被页面吞掉 */
#ac-bgm-toggle{
  position:fixed;
  top:64px;
  right:18px;
  z-index:9999;
  width:36px;
  height:36px;
  border-radius:50%;
  background:rgba(20,15,8,.78);
  border:1px solid #c9a227;
  color:#f0d48a;
  font-size:18px;
  line-height:34px;
  text-align:center;
  cursor:pointer;
  user-select:none;
  box-shadow:0 2px 8px rgba(0,0,0,.55), inset 0 1px 0 rgba(240,212,138,.25);
  transition:filter .2s, transform .2s, box-shadow .2s;
  display:flex;
  align-items:center;
  justify-content:center;
}
#ac-bgm-toggle:hover{
  filter:brightness(1.25);
  box-shadow:0 0 14px rgba(201,162,39,.55), inset 0 1px 0 rgba(240,212,138,.35);
}
#ac-bgm-toggle:active{
  transform:scale(.94);
}
/* 未静音：金色脉冲 */
#ac-bgm-toggle.ac-on{
  animation:ac-bgm-pulse 2.4s ease-in-out infinite;
}
@keyframes ac-bgm-pulse{
  0%,100%{box-shadow:0 2px 8px rgba(0,0,0,.55), 0 0 0 rgba(201,162,39,0), inset 0 1px 0 rgba(240,212,138,.25)}
  50%    {box-shadow:0 2px 8px rgba(0,0,0,.55), 0 0 14px rgba(201,162,39,.55), inset 0 1px 0 rgba(240,212,138,.35)}
}
/* 静音：灰红斜杠 */
#ac-bgm-toggle.ac-off{
  color:#a07070;
  border-color:#6b4a4a;
  animation:none;
}
#ac-bgm-toggle.ac-off:hover{
  filter:brightness(1.15);
}
/* 加载失败（音频 404 / 解码错误）：隐藏整块按钮 */
#ac-bgm-toggle.ac-hidden{
  display:none !important;
}