/* 操作領域と背景を分け、スライド下端の枠線を隠さない。 */
.slide-home-link {
  position: fixed;
  left: 50%;
  bottom: max(19px, env(safe-area-inset-bottom));
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--ink, var(--wave-foam, inherit));
  opacity: 0.48;
  text-decoration: none;
  z-index: 1000;
  transition: opacity 0.18s ease;
}

.slide-home-link::before {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 4px;
  z-index: -1;
  pointer-events: none;
}

.slide-home-link svg { width: 20px; height: 20px; }

.slide-home-link:hover,
.slide-home-link:focus-visible {
  color: var(--ink, var(--wave-foam, inherit));
  background: transparent;
  opacity: 1;
  outline: none;
}

.slide-home-link:hover::before {
  background: color-mix(in srgb, currentColor 8%, transparent);
}

.slide-home-link:focus-visible::before {
  outline: 2px solid currentColor;
  outline-offset: 1px;
}

.slide-home-tooltip {
  position: absolute;
  bottom: 48px;
  padding: 6px 10px;
  border-radius: 6px;
  background: #14243a;
  color: #fff;
  font: 13px/1.5 sans-serif;
  white-space: nowrap;
  visibility: hidden;
  pointer-events: none;
}

.slide-home-link:hover .slide-home-tooltip,
.slide-home-link:focus-visible .slide-home-tooltip { visibility: visible; }

/* 既存の全画面・画像ビューアーの操作に重ねない。 */
:fullscreen .slide-home-link,
body.is-fullscreen .slide-home-link,
body.medium-zoom--opened .slide-home-link,
body:has(.lightbox.open, .image-lightbox.open) .slide-home-link {
  display: none;
}

@media (max-width: 768px) {
  .slide-home-link { opacity: 0.8; }
  /* 旧形式の横並び操作バーがある2デッキでは、その上に置く。 */
  body:has(> .controls) .slide-home-link {
    bottom: calc(100px + env(safe-area-inset-bottom));
  }
}

@media (prefers-reduced-motion: reduce) {
  .slide-home-link { transition: none; }
}

@media (max-width: 480px) {
  /* 長い既存フッターリンクとの操作領域の重なりを避ける。 */
  .slide-home-link.slide-home-above-footer {
    bottom: max(58px, env(safe-area-inset-bottom));
  }
}

@media print {
  .slide-home-link { display: none; }
}