/* A shared return control stays absent at the top and on short pages. */
.portal-back-to-top {
  position:fixed;right:max(18px,env(safe-area-inset-right));bottom:max(18px,env(safe-area-inset-bottom));
  display:grid;place-items:center;width:44px;height:44px;min-width:44px;min-height:44px;
  margin:0;padding:0;border:1px solid rgba(66,134,179,.16);border-radius:50%;
  background:rgba(245,252,255,.96);color:#1766a4;box-shadow:0 6px 18px rgba(8,83,139,.14);
  font-family:inherit;font-size:22px;font-weight:600;line-height:1;cursor:pointer;
  z-index:100;transform:none;transition:background .18s ease,box-shadow .18s ease;
}
.portal-back-to-top[hidden] { display:none!important; }
.portal-back-to-top:focus-visible { outline:3px solid #1766a4;outline-offset:3px; }
@media(hover:hover) {
  .portal-back-to-top:hover { background:#fff;box-shadow:0 8px 22px rgba(8,83,139,.2); }
}
@media(prefers-reduced-motion:reduce) {
  html { scroll-behavior:auto!important; }
  .portal-back-to-top { transition:none; }
}