.arsip-backsound-toggle {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 9998;
  width: 42px;
  height: 42px;
  border: 1px solid rgba(181,132,26,.75);
  border-radius: 50%;
  background: rgba(24,18,10,.82);
  color: #D2A32A;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: Georgia, serif;
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(0,0,0,.18);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
}
.arsip-backsound-toggle:hover { background: rgba(181,132,26,.95); color: #fff; }
.arsip-backsound-toggle.is-playing { animation: arsipBacksoundPulse 2s ease-in-out infinite; }
@keyframes arsipBacksoundPulse {
  0%,100% { box-shadow: 0 6px 18px rgba(0,0,0,.18), 0 0 0 0 rgba(181,132,26,.25); }
  50% { box-shadow: 0 6px 18px rgba(0,0,0,.18), 0 0 0 7px rgba(181,132,26,0); }
}
@media (max-width: 600px) {
  .arsip-backsound-toggle { right: 14px; bottom: 14px; width: 38px; height: 38px; font-size: 16px; }
}