/* Persistent chrome: top bar, progress rail, footer. */

/* The top bar inverts against whatever is behind it. */
.topbar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  height: var(--topbar);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 var(--pad);
  color: #fff;
  mix-blend-mode: difference;
  font: 500 13px/1 var(--sans);
  pointer-events: none;
}
.topbar > * { pointer-events: auto; }

.brand { display: inline-flex; align-items: center; gap: 10px; justify-self: start; letter-spacing: -0.005em; }
.brand-mark { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.2; }
.brand-mark .fill { fill: currentColor; stroke: none; }
.brand:hover .brand-mark { animation: spin 2.4s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.chapters { display: flex; gap: 4px; }
.chapters a {
  position: relative;
  display: inline-flex;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 999px;
  opacity: 0.55;
  transition: opacity 0.25s;
}
.chapters a span { font: 400 10.5px/1.3 var(--mono); opacity: 0.7; }
.chapters a:hover, .chapters a.is-active { opacity: 1; }
.chapters a.is-active::after {
  content: '';
  position: absolute;
  left: 50%; bottom: 2px;
  width: 4px; height: 4px;
  margin-left: -2px;
  border-radius: 50%;
  background: currentColor;
}

.topbar-meta {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font: 400 12px/1 var(--mono);
}
.topbar-meta time { font-variant-numeric: tabular-nums; opacity: 0.7; }
.live { width: 6px; height: 6px; border-radius: 50%; background: currentColor; animation: live 2.4s ease-in-out infinite; }
@keyframes live { 50% { opacity: 0.25; } }

/* Footer */
.footer {
  display: grid;
  grid-template-columns: repeat(4, auto);
  justify-content: space-between;
  gap: 16px 32px;
  padding: 32px var(--pad) 40px;
  background: var(--paper);
  color: var(--ink-3);
  border-top: 1px solid var(--rule);
  font: 400 12px/1.5 var(--mono);
}
.footer a { transition: color 0.2s; }
.footer a:hover { color: var(--accent); }

@media (max-width: 980px) {
  .chapters { display: none; }
  .topbar { grid-template-columns: 1fr auto; }
  .footer { grid-template-columns: 1fr; }
}
@media (max-width: 520px) {
  .hide-sm { display: none; }
  .brand span { font-size: 12.5px; }
}

/* Overlay for the §01 → §02 fall (drawn by scenes/bridge.js). */
.bridge-canvas { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 30; pointer-events: none; opacity: 0.5; }

/* The floating "Explore" button, bottom right, and the links it fans out
   above itself (ui/dock.js). */
.dock {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 60;
  display: grid;
  justify-items: end;
  gap: 10px;
}
.dock-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  height: 44px;
  padding: 0 8px 0 18px;
  border: 0;
  border-radius: 999px;
  background: var(--ink);
  color: var(--paper);
  font: 500 12.5px/1 var(--mono);
  letter-spacing: 0.02em;
  cursor: pointer;
  box-shadow: 0 14px 30px -14px rgba(18, 18, 18, 0.6);
  transition: transform 0.2s var(--ease), box-shadow 0.2s;
}
.dock-toggle:hover { transform: translateY(-1px); box-shadow: 0 18px 34px -14px rgba(18, 18, 18, 0.65); }
.dock-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.dock-plus { position: relative; width: 28px; height: 28px; border-radius: 50%; background: var(--accent); transition: transform 0.35s var(--ease); }
.dock-plus::before, .dock-plus::after {
  content: '';
  position: absolute;
  left: 50%;
  top: 50%;
  width: 12px;
  height: 1.5px;
  margin: -0.75px 0 0 -6px;
  background: #fff;
  border-radius: 1px;
}
.dock-plus::after { transform: rotate(90deg); }
.dock.is-open .dock-plus { transform: rotate(135deg); }

.dock-menu { list-style: none; margin: 0; padding: 0; display: grid; justify-items: end; gap: 8px; pointer-events: none; max-height: calc(100svh - 120px); overflow: visible; }
.dock-menu li {
  opacity: 0;
  transform: translateY(12px) scale(0.96);
  transform-origin: right bottom;
  transition: opacity 0.2s var(--ease), transform 0.3s var(--ease);
  transition-delay: calc(var(--i) * 0.03s);
}
.dock.is-open .dock-menu { pointer-events: auto; }
.dock.is-open .dock-menu li { opacity: 1; transform: none; transition-delay: calc(var(--i) * 0.045s); }
.dock-item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  height: 40px;
  padding: 0 15px 0 12px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--paper);
  color: var(--ink);
  font: 400 13.5px/1 var(--sans);
  white-space: nowrap;
  box-shadow: 0 10px 24px -16px rgba(18, 18, 18, 0.5);
  transition: border-color 0.2s, color 0.2s, transform 0.2s var(--ease);
}
.dock-item:hover, .dock-item:focus-visible { border-color: var(--accent); color: var(--accent); transform: translateX(-3px); outline: none; }
.dock-icon { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.dock-hint { font: 400 11px/1 var(--mono); color: var(--ink-3); }

@media (max-width: 520px) {
  .dock { right: 14px; bottom: 14px; }
}