.back-to-top {
  position: fixed;
  right: max(22px, env(safe-area-inset-right));
  bottom: max(22px, env(safe-area-inset-bottom));
  z-index: 80;
  display: grid;
  place-items: center;
  width: 50px;
  height: 50px;
  padding: 0;
  border: 1px solid #e9d9d180;
  border-radius: 50%;
  background: #6b2b3c;
  color: #f8f3ed;
  box-shadow: 0 4px 18px #30182030;
  font: 28px/1 Arial, sans-serif;
  cursor: pointer;
  touch-action: manipulation;
}
.back-to-top[hidden] { display: none; }
.back-to-top:hover { background: #301820; }
.back-to-top:focus-visible { outline: 3px solid #f8f3ed; outline-offset: 3px; box-shadow: 0 0 0 6px #6b2b3c; }
@media (max-width: 600px) {
  .back-to-top { right: max(16px, env(safe-area-inset-right)); bottom: max(16px, env(safe-area-inset-bottom)); width: 46px; height: 46px; }
}