/* ==========================================================================
   Prime Learn Spaces — Layout Architecture (layout.css)
   Responsive Grids, Categories Dropdown, Mobile Drawer, Article Workspace & Footer
   ========================================================================== */

.site-brand,
.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  flex-shrink: 0;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.35rem;
  height: 2.35rem;
  border-radius: var(--radius-sm);
  background-color: var(--accent-primary);
  color: #ffffff;
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

/* Hide wide SVG logo when typographic lockup is present to prevent squished aspect ratio */
.site-brand img {
  display: none;
}

.site-brand-text,
.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.header-inner {
  gap: 1.5rem;
}

.site-brand-name,
.brand-title {
  font-family: var(--font-display);
  font-size: 1.22rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.site-brand-tagline,
.brand-subtitle {
  font-family: var(--font-sans);
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-top: 0.1rem;
}

.primary-nav,
.main-nav {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.primary-nav .nav-list,
.main-nav .nav-list {
  display: flex;
  align-items: center;
  gap: 1.65rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.primary-nav .nav-link,
.main-nav .nav-link {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.35rem 0;
  border: none;
  border-bottom: 2px solid transparent;
  background: transparent;
  white-space: nowrap;
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.primary-nav .nav-link:hover,
.primary-nav .nav-link.is-active,
.primary-nav .nav-link.active,
.primary-nav .nav-link[aria-current="page"],
.main-nav .nav-link:hover,
.main-nav .nav-link.active,
.main-nav .nav-link[aria-current="page"] {
  color: var(--text-primary);
  border-bottom-color: var(--accent-primary);
}

/* Navbar Categories Dropdown Menu */
.nav-dropdown,
.nav-dropdown-item {
  position: relative;
}

.nav-dropdown-trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-dropdown-caret {
  width: 14px;
  height: 14px;
  transition: transform 180ms ease;
}

.nav-dropdown.is-open .nav-dropdown-caret,
.nav-dropdown-item.is-open .nav-dropdown-caret,
.nav-dropdown-trigger[aria-expanded="true"] .nav-dropdown-caret {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 0.5rem);
  left: -1rem;
  width: min(560px, 90vw);
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.35rem;
  padding: 0.85rem;
  margin: 0;
  list-style: none;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  z-index: 220;
}

.nav-dropdown.is-open .nav-dropdown-menu,
.nav-dropdown-item.is-open .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu,
.nav-dropdown-item:focus-within .nav-dropdown-menu {
  display: grid;
}

@media (hover: hover) and (pointer: fine) {
  .nav-dropdown:hover .nav-dropdown-menu,
  .nav-dropdown-item:hover .nav-dropdown-menu {
    display: grid;
  }
}

.nav-dropdown-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.6rem 0.75rem;
  font-family: var(--font-sans);
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease;
}

.nav-dropdown-link:hover,
.nav-dropdown-link:focus-visible {
  background-color: var(--bg-elevated);
  border-color: var(--border-color);
  color: var(--accent-primary);
}

.nav-dropdown-count {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-muted);
  background-color: var(--bg-subtle);
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.header-search-btn,
.search-trigger-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.45rem 0.85rem;
  font-family: var(--font-sans);
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-secondary);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
}

.header-search-btn:hover,
.search-trigger-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
  background-color: var(--bg-elevated);
}

.header-search-btn svg,
.search-trigger-btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.search-trigger-btn kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.05rem 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: 3px;
}

/* Mobile Navigation Drawer & Backdrop (Hidden by Default) */
.mobile-drawer-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background-color: rgba(24, 24, 22, 0.48);
  z-index: 190;
}

.mobile-drawer-backdrop.is-open {
  display: block;
}

.mobile-drawer {
  display: none;
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(340px, 88vw);
  background-color: var(--bg-surface);
  border-left: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  z-index: 200;
  padding: 1.25rem 1.5rem;
  overflow-y: auto;
}

.mobile-drawer.is-open {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.mobile-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.mobile-drawer-close {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.mobile-nav-section {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.mobile-nav-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.mobile-drawer .mobile-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.mobile-drawer .mobile-nav-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.45rem;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  text-decoration: none;
}

.mobile-drawer .mobile-nav-list a:hover {
  color: var(--accent-primary);
}

/* Article Detail Layout */
.article-hero {
  padding: var(--space-8) 0 var(--space-6);
  border-bottom: 1px solid var(--border-color);
}

.article-headline {
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 3.4vw, 2.85rem);
  font-weight: 700;
  line-height: 1.28;
  color: var(--text-primary);
  margin: var(--space-3) 0 var(--space-4);
}

.article-standfirst {
  font-family: var(--font-serif);
  font-size: clamp(1.05rem, 1.4vw, 1.22rem);
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: var(--space-5);
}

.article-workspace {
  display: grid;
  grid-template-columns: 270px minmax(0, 1fr);
  gap: var(--space-10);
  padding: var(--space-10) 0 var(--space-14);
  align-items: start;
}

.article-toc-sidebar {
  position: sticky;
  top: 5.5rem;
}

.article-main-col {
  min-width: 0;
}

.related-section {
  padding: var(--space-12) 0;
  background-color: var(--bg-elevated);
  border-top: 1px solid var(--border-color);
}

/* Footer Column Helpers */
.footer-col-title {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-primary);
  margin-bottom: var(--space-4);
}

.footer-link-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-link-list a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-link-list a:hover {
  color: var(--accent-primary);
}

@media (max-width: 980px) {
  .primary-nav,
  .main-nav {
    display: none;
  }

  .mobile-menu-toggle {
    display: inline-flex;
  }
}

@media (max-width: 1024px) {
  .article-workspace {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .article-toc-sidebar {
    position: static;
  }
}

@media (max-width: 768px) {
  .article-grid-3 {
    grid-template-columns: 1fr !important;
  }

  .announcement-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
  }

  .header-search-btn span {
    display: none;
  }
}