/* ============================================================
   CAAT Side Navigation — Component CSS
   AEM client library: caat/components/side-nav/clientlibs/css
   Depends on: tokens.css (consumes SEMANTIC tokens)

   Left-hand navigation for the current Level 3 branch. It shows
   only that branch's Level 4 pages. Higher levels remain available
   through the mega navigation and breadcrumb.
   ============================================================ */

.caat-side-nav {
  font-size: var(--caat-font-size-sm);
}

/* Sticky variant for long pages (desktop only — below lg the nav
   stacks above content in normal flow, so sticky is a no-op). */
.caat-side-nav--sticky {
  position: sticky;
  top: 5rem;   /* matches global scroll-padding-top */
}

/* ── Current L3 branch label — context only, not a link ─────── */
.caat-side-nav__heading {
  font-size: var(--caat-font-size-md);
  font-weight: var(--caat-weight-extrabold);
  color: var(--caat-color-text-heading);
  padding: var(--caat-space-2) var(--caat-space-3);
  border-bottom: var(--caat-border-2) solid var(--caat-color-border);
  margin-bottom: var(--caat-space-2);
  line-height: var(--caat-leading-heading);
}

/* ── Current branch's L4 list ────────────────────────────────── */
.caat-side-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.caat-side-nav__link {
  display: block;
  padding: var(--caat-space-2) var(--caat-space-3);
  color: var(--caat-color-text);
  font-weight: var(--caat-weight-semibold);
  text-decoration: none;
  border-left: var(--caat-border-2) solid transparent;
  border-radius: 0 var(--caat-radius-sm) var(--caat-radius-sm) 0;
}
.caat-side-nav__link:hover,
.caat-side-nav__link.is-hover {
  background: var(--caat-color-state-hover-bg);
  color: var(--caat-color-text-heading);
}
.caat-side-nav__link:focus-visible,
.caat-side-nav__link.is-focus {
  outline: 0;
  box-shadow: var(--caat-color-focus-ring);
}

/* Current L4 page — rendered server-side. */
.caat-side-nav__link[aria-current="page"] {
  border-left-color: var(--caat-color-action-primary);
  color: var(--caat-color-text-heading);
  font-weight: var(--caat-weight-bold);
  background: var(--caat-color-bg-brand-subtle);
}

/* ── Mobile disclosure ─────────────────────────────────────────
   Below the desktop tier the nav collapses behind a PROMINENT
   "In this section" toggle (QLD Gov DS / USWDS pattern; DTA testing
   found subtle collapsed navs get overlooked — hence the strong bar).
   JS (side-nav.js) adds --collapsible; without it the nav simply
   stays expanded (progressive enhancement). The toggle is hidden on
   desktop. */
.caat-side-nav__toggle {
  display: none;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: var(--caat-space-2);
  min-height: 2.75rem;                 /* ≥ 44px touch target */
  padding: var(--caat-space-3);
  background: var(--caat-color-bg-brand-subtle);
  border: var(--caat-border-1) solid var(--caat-color-border-strong);
  border-radius: var(--caat-radius-sm);
  font-size: var(--caat-font-size-sm);
  font-weight: var(--caat-weight-bold);
  color: var(--caat-color-text-heading);
  text-align: left;
  cursor: pointer;
}
.caat-side-nav__toggle .bi {
  transition: transform var(--caat-duration-base) var(--caat-ease-standard);
}
.caat-side-nav__toggle:hover { background: var(--caat-color-state-hover-bg); }
.caat-side-nav__toggle:focus-visible {
  outline: 0;
  box-shadow: var(--caat-color-focus-ring);
}

@media (max-width: 991.98px) {
  .caat-side-nav__toggle { display: flex; }
  .caat-side-nav--collapsible:not(.is-open) .caat-side-nav__body { display: none; }
  .caat-side-nav--collapsible.is-open .caat-side-nav__toggle .bi { transform: rotate(180deg); }
  .caat-side-nav--collapsible.is-open .caat-side-nav__body {
    margin-top: var(--caat-space-2);
    border: var(--caat-border-1) solid var(--caat-color-border);
    border-radius: var(--caat-radius-sm);
    padding: var(--caat-space-2);
  }
  /* Sticky is a desktop behaviour */
  .caat-side-nav--sticky { position: static; }
}