/* AI Architect Academy — shared site navigation: breadcrumb trail + back-to-top button.
   Uses CSS variables defined by each page's base stylesheet (tokens.css / landing.css / inline). */

/* ---- breadcrumb ---- */

nav.crumbs {
  margin: 14px 0 4px;
}

ol.crumbs-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
}

ol.crumbs-list li {
  display: flex;
  align-items: center;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .08em;
}

/* separator: "/" before every item except the first */
ol.crumbs-list li + li::before {
  content: "/";
  color: var(--ink-faint);
  margin: 0 6px;
}

ol.crumbs-list li a {
  color: var(--ink-dim);
  text-decoration: none;
  transition: color .15s ease;
}

ol.crumbs-list li a:hover,
ol.crumbs-list li a:focus-visible {
  color: var(--amber-soft);
}

/* current page — use ink-dim for safe WCAG AA at this small size */
ol.crumbs-list li span[aria-current="page"] {
  color: var(--ink-dim);
}

/* ---- back-to-top button ---- */

.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 60;

  /* sizing — 46px visual, 44px min touch target */
  width: 46px;
  height: 46px;
  min-width: 44px;
  min-height: 44px;
  padding: 0;

  /* shape */
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--panel);
  cursor: pointer;

  /* icon centering */
  display: grid;
  place-items: center;

  /* amber icon */
  color: var(--amber);

  box-shadow: 0 2px 12px rgba(0, 0, 0, .45);

  /* hidden by default */
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  pointer-events: none;

  transition: opacity .2s ease, transform .2s ease, visibility .2s ease, border-color .15s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  border-color: var(--amber);
  transform: translateY(-1px);
}

.back-to-top.is-visible:hover {
  transform: translateY(-1px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
  display: block;
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top,
  .back-to-top:hover,
  .back-to-top.is-visible:hover {
    transition: none;
    transform: none;
  }
}