.back-to-top {
  position: fixed;
  right: max(16px, env(safe-area-inset-right));
  bottom: max(16px, env(safe-area-inset-bottom));
  z-index: 75;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  min-height: 44px;
  padding: 0;
  border: 1px solid var(--line, #d9e3ea);
  border-radius: 50%;
  color: var(--accent-strong, #002fa7);
  background: var(--surface, #fff);
  box-shadow: 0 4px 16px #17212b24;
  cursor: pointer;
  touch-action: manipulation;
}
.back-to-top[hidden] { display: none !important; }
.back-to-top:hover { background: var(--surface-soft, #eef3fb); }
.back-to-top:focus-visible { outline: 2px solid var(--accent-strong, #002fa7); outline-offset: 3px; }
.back-to-top-surface,
body.app-mode .song-detail-panel { padding-bottom: 72px !important; }
@media print { .back-to-top { display: none; } }