.site-back-to-top {
  position: fixed; z-index: 60;
  right: max(var(--back-top-right, 16px), calc(env(safe-area-inset-right, 0px) + 12px));
  bottom: max(var(--back-top-bottom, 20px), calc(env(safe-area-inset-bottom, 0px) + 16px));
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 1px;
  box-sizing: border-box; width: 48px; min-height: 48px; padding: 5px;
  border: 1px solid var(--ui-line, #dce3ed); border-radius: 12px;
  background: var(--ui-surface, #fff); color: var(--ui-accent, #2877d8);
  box-shadow: 0 3px 14px #14264214; font: inherit; font-size: 11px; line-height: 1.2;
  cursor: pointer; touch-action: manipulation; -webkit-tap-highlight-color: transparent;
}
.site-back-to-top[hidden] { display: none !important; }
.site-back-to-top > span { margin: 0; }
.site-back-to-top > svg { flex: none; }
.site-back-to-top:hover { background: var(--ui-soft, #eef5ff); }
.site-back-to-top:focus-visible { outline: 2px solid var(--ui-accent, #2877d8); outline-offset: 3px; }
body:has(dialog[open]) .site-back-to-top { display: none; }
@media (max-width: 760px) {
  body:has(input:focus, textarea:focus, [contenteditable="true"]:focus) .site-back-to-top { display: none; }
}
@media print { .site-back-to-top { display: none !important; } }