.cassell-back {
  position: fixed; left: max(14px, env(safe-area-inset-left));
  bottom: max(16px, env(safe-area-inset-bottom)); z-index: 9998;
  min-width: 82px; height: 38px; padding: 0 16px;
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 1px solid rgba(190,210,240,.48); border-radius: 999px;
  background: rgba(5,12,24,.88); color: #dbe8fb;
  font: 600 11px/1 "Cinzel",serif; letter-spacing: .18em; text-decoration: none;
  box-shadow: 0 8px 24px rgba(0,0,0,.35); backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px); cursor: pointer;
  transition: transform .2s ease,border-color .2s ease,background .2s ease;
}
.cassell-back:hover,.cassell-back:focus-visible { transform: translateY(-2px); border-color: rgba(224,236,255,.82); background: rgba(12,25,45,.96); outline: none; }
.cassell-back::before { content: "←"; font: 15px/1 sans-serif; letter-spacing: 0; }
@media (max-width:600px) {
  .cassell-back {
    top: auto; bottom: max(14px, env(safe-area-inset-bottom));
    min-width:72px; height:36px; padding:0 13px; font-size:10px;
    backdrop-filter:none; -webkit-backdrop-filter:none;
  }
}
@media (prefers-reduced-motion:reduce) { .cassell-back { transition:none; } }