.to-top-btn {
  position: fixed;
  right: 18px;
  bottom: calc(72px + env(safe-area-inset-bottom, 0px));
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.06), rgba(5,5,7,0.7));
  color: #cfd4e6;
  font-size: 18px;
  display: grid;
  place-items: center;
  text-align: center;
  cursor: pointer;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease, background 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease, color 0.2s ease;
  box-shadow: 0 10px 18px rgba(0, 0, 0, 0.32);
  z-index: 998;
  backdrop-filter: blur(6px);
}

.to-top-btn.is-visible { opacity: 1; transform: translateY(0); pointer-events: auto; }

.to-top-btn:hover {
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.1), rgba(5,5,7,0.74));
  border-color: rgba(255, 255, 255, 0.22);
  box-shadow: 0 12px 20px rgba(0,0,0,0.42);
  color: #f4e9ff;
  transform: translateY(-1px);
}

.sound-toggle {
  position: fixed;
  right: 18px;
  bottom: calc(18px + env(safe-area-inset-bottom, 0px));
  z-index: 999;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.08), rgba(5,5,7,0.65));
  color: #f9c0e8;
  font-size: 18px;
  cursor: pointer;
  box-shadow: 0 12px 24px rgba(0,0,0,0.45);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.sound-toggle:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 26px rgba(0,0,0,0.5);
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.14), rgba(5,5,7,0.7));
}

.sound-toggle.is-muted {
  color: #888a94;
  border-color: rgba(255, 255, 255, 0.12);
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.05), rgba(5,5,7,0.7));
}

.playlist {
  position: fixed;
  left: 18px;
  bottom: calc(18px + env(safe-area-inset-bottom, 0px));
  z-index: 999;
  display: grid;
  gap: 6px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(5, 5, 7, 0.72);
  box-shadow: 0 12px 24px rgba(0,0,0,0.45);
  backdrop-filter: blur(8px);
}

.playlist-title {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: #cfd4e6;
  text-transform: uppercase;
}

.track-btn {
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.05);
  color: #f7d9f2;
  padding: 8px 10px;
  font-size: 13px;
  text-align: left;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
}

.track-btn:hover { background: rgba(255, 255, 255, 0.08); border-color: rgba(255, 134, 209, 0.4); transform: translateY(-1px); }

.track-btn.is-active { border-color: rgba(255, 134, 209, 0.65); background: rgba(255, 134, 209, 0.1); }

@media (max-width: 640px) {
  .to-top-btn { right: 14px; bottom: calc(70px + env(safe-area-inset-bottom, 0px)); width: 50px; height: 50px; font-size: 19px; }
  .sound-toggle { right: 14px; bottom: calc(14px + env(safe-area-inset-bottom, 0px)); width: 48px; height: 48px; }
  .playlist { left: 14px; bottom: calc(14px + env(safe-area-inset-bottom, 0px)); grid-template-columns: 1fr; }
}