/* ============================================================
   Navigation layer
   - Braille Q logo trigger (header desktop + bottom-corner mobile)
   - Summoned overlay: the full web as an accessible node list
   - Constellation.design link
   Threads carry color; the overlay stays calm and paper/chalk-toned.
   ============================================================ */

/* --- Logo trigger (header, desktop) --- */

/* The header logo is a plain link home (no longer a nav trigger). It reads
   subtle at rest and lifts gently on hover. */
.site-header .logo {
  display: block;
  height: 44px;
  width: 44px;
  padding: 0;
  border: none;
  background: none;
  color: var(--fg);
  cursor: pointer;
  border-radius: 10px;
  transition: transform var(--transition), opacity var(--transition),
    filter var(--transition);
}

.site-header .logo .logo-mark {
  width: 100%;
  height: 100%;
}

.site-header .logo:hover {
  transform: translateY(-2px);
}

/* --- Mobile bottom-corner logo (primary trigger on touch) --- */

.mobile-logo.nav-trigger {
  display: none; /* desktop hides it; the header logo is primary there */
  position: fixed;
  right: max(var(--space-4), env(safe-area-inset-right));
  bottom: max(var(--space-4), env(safe-area-inset-bottom));
  width: 56px;
  height: 56px;
  padding: 12px;
  border-radius: 999px;
  border: var(--border);
  background: var(--bg-base);
  color: var(--fg);
  box-shadow: var(--shadow-md);
  cursor: pointer;
  z-index: var(--z-header);
  transition: transform var(--transition), box-shadow var(--transition),
    background var(--transition);
}

.mobile-logo.nav-trigger .logo-mark {
  width: 100%;
  height: 100%;
}

.mobile-logo.nav-trigger.is-active {
  transform: scale(1.06);
  box-shadow: var(--shadow-lg);
  background: var(--paper);
}

@media (max-width: 768px) {
  .mobile-logo.nav-trigger {
    display: block;
  }
  /* On mobile the header logo steps aside; the corner logo leads. */
  .site-header .logo {
    display: none;
  }
}

/* --- The summoned overlay --- */

.nav-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-nav-overlay);
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: var(--space-6);
  padding: clamp(var(--space-6), 6vh, var(--space-8))
    clamp(var(--space-6), 6vw, 4rem);
  align-content: center;
  justify-items: center;

  background: var(--bg-base);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);

  opacity: 0;
  pointer-events: none;
  transition: opacity 260ms ease;
}

.nav-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.nav-overlay[hidden] {
  display: none;
}

/* Overlay header: the kicker sits in the first grid row (centered) with the
   close button pinned to that row's right edge. Keeping the close button
   inside a dedicated header row — rather than absolutely positioned over the
   whole overlay — means it can never land on top of the kicker text, whatever
   the overlay's height or vertical alignment. */
.nav-overlay-header {
  grid-row: 1;
  justify-self: stretch;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  position: relative;
}

.nav-overlay-close {
  position: absolute;
  top: 50%;
  right: max(0px, env(safe-area-inset-right));
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: var(--paper);
  border: var(--border);
  color: var(--fg);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}
.nav-overlay-close:hover {
  background: color-mix(in srgb, var(--fg) 6%, var(--paper));
  transform: translateY(-50%) translateY(-1px);
}

.nav-overlay-kicker {
  margin: 0;
  /* Reserve room so the centered kicker never slides under the close button. */
  padding: 0 56px;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: var(--size-sm);
  color: var(--muted);
}

/* The web, rendered as a legible list of the whole collection. */
.nav-overlay-web {
  width: 100%;
  max-width: 720px;
  overflow-y: auto;
  align-self: center;
}

.nav-web-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-3);
}

.nav-web-item {
  margin: 0;
}

/* One node = one real button. The type glyph reads muted (nodes recede);
   a small thread-colored bead carries the connection color, matching the
   landing's "nodes muted, threads sing" without a loud side-tab border. */
.nav-web-node {
  --accent: var(--thread-questions);
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-4);
  min-height: 56px; /* comfortable target on every device */
  padding: var(--space-3) var(--space-4);
  text-align: left;
  background: var(--paper);
  border: var(--border);
  border-radius: var(--radius);
  color: var(--fg);
  cursor: pointer;
  transition: transform var(--transition), background var(--transition),
    box-shadow var(--transition);
}

.nav-web-node:hover {
  transform: translateY(-1px);
  background: color-mix(in srgb, var(--accent) 8%, var(--paper));
  box-shadow: var(--shadow-sm);
}

.nav-web-glyph {
  position: relative;
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  color: var(--node-default);
}

/* Thread bead: a small colored dot tying the node to its primary thread. */
.nav-web-node::before {
  content: "";
  flex: 0 0 auto;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent);
}

.nav-web-node[data-type="essay"] .nav-web-glyph { color: var(--node-essay); }
.nav-web-node[data-type="durational"] .nav-web-glyph { color: var(--node-durational); }
.nav-web-node[data-type="curiosity"] .nav-web-glyph { color: var(--node-curiosity); }
.nav-web-node[data-type="bio"] .nav-web-glyph { color: var(--node-bio); }

/* Glyphs echo the landing markers so the two views feel like one system. */
.nav-web-glyph[data-type="essay"] {
  width: 16px; height: 20px; border-radius: 3px; background: currentColor;
  align-self: center;
}
.nav-web-glyph[data-type="durational"] {
  border-radius: 50%; border: 2px solid currentColor; background: transparent;
}
.nav-web-glyph[data-type="durational"]::after {
  content: ""; position: absolute; left: 50%; top: 50%;
  width: 7px; height: 7px; border-radius: 50%; background: currentColor;
  transform: translate(-50%, -50%);
}
.nav-web-glyph[data-type="curiosity"] {
  background: transparent;
}
.nav-web-glyph[data-type="curiosity"]::before,
.nav-web-glyph[data-type="curiosity"]::after {
  content: ""; position: absolute; border-radius: 50%; background: currentColor;
}
.nav-web-glyph[data-type="curiosity"]::before {
  width: 7px; height: 7px; left: 1px; top: 11px;
  box-shadow: 12px 3px 0 -1px currentColor;
}
.nav-web-glyph[data-type="curiosity"]::after {
  width: 8px; height: 8px; left: 8px; top: 1px;
}

.nav-web-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.nav-web-kind {
  font-size: 0.66rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  font-weight: 600;
  color: var(--accent);
}

.nav-web-title {
  font-size: var(--size-md);
  font-weight: 500;
  color: var(--fg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Constellation link, revealed with the map (spec: appears when nav prominent). */
.nav-overlay-constellation {
  display: block;
  width: fit-content;
  opacity: 0.85;
  transition: opacity var(--transition), transform var(--transition);
}
.nav-overlay-constellation:hover {
  opacity: 1;
  transform: translateY(-1px);
}
.nav-overlay-constellation .constellation-logo {
  width: 200px;
  height: auto;
}

/* --- Focus-visible: consistent, visible, thread-aware --- */

.nav-trigger:focus-visible,
.site-header .logo:focus-visible,
.nav-web-node:focus-visible,
.nav-overlay-close:focus-visible,
.nav-overlay-constellation:focus-visible,
.theme-toggle:focus-visible,
.container-close:focus-visible {
  outline: 2px solid var(--thread-movement);
  outline-offset: 3px;
  border-radius: 10px;
}

/* Landing nodes: focus ring hugs the whole node control. */
.node:focus-visible {
  outline: 2px solid var(--thread-movement);
  outline-offset: 6px;
  border-radius: 12px;
}

/* Curiosity linked items keyboard focus. */
.curiosity-item-linked:focus-visible {
  outline: 2px solid var(--thread-movement);
  outline-offset: 3px;
}

/* --- Mobile overlay: tighter gutters, rows that never overflow --- */
@media (max-width: 768px) {
  .nav-overlay {
    padding: max(var(--space-8), env(safe-area-inset-top)) var(--space-4)
      max(var(--space-6), env(safe-area-inset-bottom));
    gap: var(--space-4);
    align-content: start;
  }
  .nav-overlay-web {
    max-width: 100%;
  }
  .nav-web-node {
    /* Let long titles wrap to a second line rather than clip off-screen. */
    min-width: 0;
  }
  .nav-web-title {
    white-space: normal;
  }
  .nav-overlay-constellation .constellation-logo {
    width: 160px;
  }
}

/* --- Reduced motion: overlay collapses to a plain crossfade --- */
@media (prefers-reduced-motion: reduce) {
  .site-header .logo,
  .mobile-logo.nav-trigger,
  .nav-web-node,
  .nav-overlay-constellation {
    transition: opacity 120ms linear, background 120ms linear;
  }
  .site-header .logo:hover,
  .mobile-logo.nav-trigger.is-active,
  .nav-web-node:hover,
  .nav-overlay-constellation:hover {
    transform: none;
  }
}