/* Floating Navigation Dock: one material surface, native parent link and
   optional reading buttons. No timer/scroll listener: controls stay discoverable. */
.floating-navigation-dock {
  --dock-gutter: max(0.5rem, calc(env(safe-area-inset-left) + 0.25rem));
  position: fixed;
  z-index: 8;
  left: var(--dock-gutter);
  bottom: max(0.75rem, env(safe-area-inset-bottom));
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem;
  width: max-content;
  max-width: calc(100% - var(--dock-gutter) - max(0.5rem, calc(env(safe-area-inset-right) + 0.25rem)));
  padding: 0.35rem;
  border: 1px solid var(--line);
  border-radius: 1.75rem;
  background: var(--glass-background);
  color: var(--text);
  box-shadow: var(--glass-shadow);
  -webkit-backdrop-filter: var(--glass-filter);
  backdrop-filter: var(--glass-filter);
}

.floating-navigation-dock .back-control {
  flex: 1 1 auto;
  min-width: 0;
  max-width: 12rem;
  min-height: 3rem;
  padding: 0.5rem 0.75rem;
}
.floating-navigation-dock .back-control[hidden] { display: none; }
.back-control > [aria-hidden="true"] { flex: none; font-size: 1.35rem; }
.back-control [data-back-label] { min-width: 0; overflow-wrap: anywhere; }

.dock-reading-controls {
  display: flex;
  flex: none;
  align-items: center;
  gap: 0.25rem;
  margin-left: auto;
}

.floating-navigation-dock:has(.back-control:not([hidden])) .dock-reading-controls {
  padding-left: 0.35rem;
  border-left: 1px solid var(--line);
}

.floating-navigation-dock[hidden] { display: none; }
.dock-reading-controls[hidden] { display: none; }
/* Reserve the previous action slot: repeated taps must not move Next. */
.floating-navigation-dock .scroll-guide:disabled { visibility: hidden; }

.floating-navigation-dock .scroll-guide {
  --scroll-progress: 0deg;
  position: relative;
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  flex: none;
  padding: 0;
}

.floating-navigation-dock [data-scroll-guide="next"] {
  border: 0;
  background: conic-gradient(var(--sea) var(--scroll-progress), var(--line) 0deg);
}

.floating-navigation-dock [data-scroll-guide="next"]::before {
  content: "";
  position: absolute;
  inset: 2px;
  border-radius: inherit;
  background: var(--deep);
}

.scroll-guide-icon {
  position: relative;
  font-size: 1.25rem;
  line-height: 1;
  transition: transform var(--motion-fast) var(--ease-natural);
}

.floating-navigation-dock :is(a, button):hover { color: var(--sea); }
.floating-navigation-dock :is(a, button):focus-visible {
  outline: 2px solid var(--sea);
  outline-offset: 0.2rem;
}

/* Keep final links reachable even when labels wrap at larger text settings. */
body:has(.floating-navigation-dock:not([hidden])) .site-footer {
  padding-bottom: calc(10rem + env(safe-area-inset-bottom));
}

html.is-viewer-locked .floating-navigation-dock,
body.is-viewer-locked .floating-navigation-dock,
body:has(dialog[open]) .floating-navigation-dock { visibility: hidden; }

@media (min-width: 48rem) {
  .floating-navigation-dock {
    --dock-gutter: max(1.5rem, calc(env(safe-area-inset-left) + 0.25rem));
    bottom: max(1.5rem, env(safe-area-inset-bottom));
  }
}

@media (prefers-reduced-motion: reduce) {
  .floating-navigation-dock .scroll-guide-icon { transition: none; }
}

@media (forced-colors: active) {
  .floating-navigation-dock,
  .floating-navigation-dock .scroll-guide,
  .dock-reading-controls { border: 1px solid ButtonText; }
}