/* ==========================================================================
   Contexa Layout
   Header, Footer, Navigation, Grid System
   ========================================================================== */

/* ── Site Header ── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg-nav);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  z-index: var(--z-sticky);
  transition: box-shadow var(--transition-normal), background-color var(--transition-normal);
  border-bottom: 1px solid rgba(0, 0, 0, 0.04);
}

.site-header.scrolled {
  background: var(--bg-nav-scrolled);
  box-shadow: var(--shadow-nav);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.header-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ── Logo ── */
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: #000000;
  flex-shrink: 0;
}

.logo-icon {
  width: 64px;
  height: 64px;
  object-fit: contain;
  border-radius: var(--radius-md);
}

.logo-text {
  font-size: 1.85rem;
  font-weight: var(--weight-extrabold);
  letter-spacing: 0.06em;
  line-height: 1;
  color: #000000;
}

.logo-x {
  color: var(--brand-accent);
}

.logo-tagline {
  font-size: 0.7rem;
  color: rgba(0, 0, 0, 0.38);
  font-weight: var(--weight-medium);
  letter-spacing: 0.02em;
  margin-left: var(--space-3);
  padding-left: var(--space-3);
  border-left: 1px solid rgba(0, 0, 0, 0.1);
  line-height: 1.4;
}

/* ── Main Navigation ── */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: var(--weight-semibold);
  color: #000000;
  text-decoration: none;
  background: none;
  border: none;
  font-family: var(--font-sans);
  border-radius: var(--radius-md);
  transition: color 200ms ease, background-color 200ms ease;
  white-space: nowrap;
  letter-spacing: -0.005em;
  cursor: pointer;
}

.nav-link:hover {
  color: #000000;
  background-color: rgba(0, 0, 0, 0.05);
}

.nav-link.active {
  color: #000000;
  background-color: rgba(0, 0, 0, 0.06);
}

.nav-chevron {
  width: 11px;
  height: 11px;
  transition: transform 200ms ease;
  opacity: 0.4;
}

.nav-item:hover .nav-chevron {
  transform: rotate(180deg);
  opacity: 0.8;
}

/* ── Dropdown Menu ── */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  padding-top: var(--space-2);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
  z-index: var(--z-dropdown);
}

.nav-item:hover > .nav-dropdown {
  opacity: 1;
  visibility: visible;
}

.dropdown-panel {
  background: var(--bg-dropdown);
  backdrop-filter: blur(32px) saturate(180%);
  -webkit-backdrop-filter: blur(32px) saturate(180%);
  border: none;
  border-radius: var(--radius-xl);
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.12), 0 4px 16px rgba(0, 0, 0, 0.06);
  padding: var(--space-6);
  min-width: 260px;
}

.dropdown-panel-mega {
  min-width: 660px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
}

.dropdown-section-title {
  font-size: 0.75rem;
  font-weight: var(--weight-bold);
  color: var(--brand-primary);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--border-light);
}

.dropdown-link {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background-color 150ms ease;
  margin-bottom: 2px;
}

.dropdown-link:hover {
  background-color: rgba(0, 0, 0, 0.04);
}

.dropdown-link-title {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: #000000;
  display: block;
  margin-bottom: 1px;
}

.dropdown-link-desc {
  font-size: var(--text-xs);
  color: rgba(0, 0, 0, 0.45);
  display: block;
  line-height: var(--leading-normal);
}

/* ── Header Actions ── */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* ── Header Search Button ── */
.header-search-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 8px 14px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  color: var(--text-tertiary);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: border-color var(--transition-fast), color var(--transition-fast);
  white-space: nowrap;
}

.header-search-btn:hover {
  border-color: var(--border-medium);
  color: var(--text-secondary);
}

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

.header-search-kbd {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  padding: 2px 6px;
  background: var(--bg-primary);
  border: 1px solid var(--border-light);
  border-radius: 3px;
  color: var(--text-tertiary);
  margin-left: var(--space-2);
}

/* ── Search Modal ── */
.search-modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  z-index: var(--z-modal);
  justify-content: center;
  padding-top: 15vh;
}

.search-modal-overlay.open {
  display: flex;
}

.search-modal {
  width: 100%;
  max-width: 560px;
  max-height: 60vh;
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.search-modal-input-wrap {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--border-light);
}

.search-modal-input-wrap svg {
  width: 20px;
  height: 20px;
  color: var(--text-tertiary);
  flex-shrink: 0;
}

.search-modal-input {
  flex: 1;
  border: none;
  background: none;
  font-size: var(--text-base);
  font-family: var(--font-sans);
  color: var(--text-primary);
  outline: none;
}

.search-modal-input::placeholder {
  color: var(--text-tertiary);
}

.search-modal-results {
  overflow-y: auto;
  padding: var(--space-2);
}

.search-modal-results:empty::after {
  content: 'Type to search documentation...';
  display: block;
  text-align: center;
  padding: var(--space-8) var(--space-4);
  color: var(--text-tertiary);
  font-size: var(--text-sm);
}

.search-result-item {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background-color var(--transition-fast);
}

.search-result-item:hover,
.search-result-item.active {
  background: var(--bg-secondary);
}

.search-result-title {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  display: block;
}

.search-result-path {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  display: block;
  margin-top: 2px;
}

.search-results-group { margin-bottom: var(--space-2); }
.search-group-label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: var(--space-2) var(--space-4);
  border-bottom: 1px solid var(--border-light);
}
.search-result-snippet {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  display: block;
  margin-top: 4px;
  line-height: 1.5;
  overflow: hidden;
  text-overflow: ellipsis;
  max-height: 2.5em;
}
.search-result-snippet mark {
  background: rgba(0, 194, 224, 0.2);
  color: inherit;
  padding: 0 2px;
  border-radius: 2px;
}

.search-modal-footer {
  padding: var(--space-2) var(--space-4);
  border-top: 1px solid var(--border-light);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  display: flex;
  gap: var(--space-4);
}

.search-modal-footer kbd {
  font-family: var(--font-sans);
  padding: 1px 4px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: 3px;
  font-size: 0.65rem;
}

.lang-switcher {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: var(--text-sm);
  font-weight: 500;
}

.lang-option {
  color: rgba(0, 0, 0, 0.45);
  text-decoration: none;
  padding: 2px 4px;
  border-radius: 3px;
  transition: color 0.15s, background 0.15s;
}

.lang-option:hover {
  color: var(--color-primary);
}

.lang-option.active {
  color: var(--color-primary);
  font-weight: 700;
}

.lang-separator {
  color: rgba(0, 0, 0, 0.2);
  user-select: none;
}

.github-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: var(--weight-semibold);
  color: rgba(0, 0, 0, 0.6);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: color 200ms ease, background-color 200ms ease;
}

.github-link:hover {
  color: #000000;
  background-color: rgba(0, 0, 0, 0.05);
}

.github-link svg {
  width: 22px;
  height: 22px;
}

/* ── Mobile Menu Toggle ── */
.mobile-menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: none;
  background: none;
  cursor: pointer;
  border-radius: var(--radius-md);
  color: #000000;
  transition: background-color 200ms ease;
}

.mobile-menu-toggle:hover {
  background-color: rgba(0, 0, 0, 0.05);
}

.mobile-menu-toggle svg {
  width: 24px;
  height: 24px;
}

/* ── Mobile Navigation ── */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  z-index: var(--z-overlay);
  overflow-y: auto;
  padding: var(--space-4) var(--space-6) var(--space-8);
}

.mobile-nav.open {
  display: block;
}

.mobile-nav-section {
  margin-bottom: var(--space-6);
}

.mobile-nav-title {
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-widest);
  margin-bottom: var(--space-2);
}

.mobile-nav-link {
  display: block;
  padding: var(--space-3) 0;
  font-size: var(--text-base);
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 1px solid var(--border-light);
  transition: color var(--transition-fast);
}

.mobile-nav-link:hover {
  color: var(--brand-primary);
}

/* ── Main Content Area ── */
.site-main {
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
}

/* ── Page Header (used in sub-pages) ── */
.page-header {
  background: var(--bg-hero-gradient);
  padding: var(--space-16) 0 var(--space-12);
  border-bottom: 1px solid var(--border-light);
}

.page-header h1 {
  margin-bottom: var(--space-4);
}

.page-header .lead {
  max-width: 640px;
}

/* ── Breadcrumb ── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.breadcrumb a:hover {
  color: var(--brand-primary);
}

.breadcrumb-separator {
  color: var(--border-medium);
  font-size: var(--text-xs);
}

.breadcrumb-current {
  color: var(--text-secondary);
  font-weight: var(--weight-medium);
}

/* ── Site Footer ── */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-light);
  padding: var(--space-16) 0 var(--space-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-brand {
  max-width: 320px;
}

.footer-brand .logo {
  margin-bottom: var(--space-4);
}

.footer-brand .logo-icon {
  width: 48px;
  height: 48px;
}

.footer-brand-desc {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-4);
}

.footer-section-title {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-4);
  letter-spacing: var(--tracking-wide);
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--brand-primary);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-8);
  border-top: 1px solid var(--border-light);
}

.footer-copyright {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
}

.footer-legal {
  display: flex;
  gap: var(--space-6);
}

.footer-legal a {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-legal a:hover {
  color: var(--brand-primary);
}

/* ==========================================================================
   Dark Mode Overrides (hardcoded colors)
   ========================================================================== */

[data-theme="dark"] .site-header {
  border-bottom-color: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .site-header.scrolled {
  border-bottom-color: rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .logo,
[data-theme="dark"] .logo-text {
  color: var(--text-primary);
}

[data-theme="dark"] .logo-tagline {
  color: rgba(255, 255, 255, 0.38);
  border-left-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .nav-link {
  color: var(--text-primary);
}

[data-theme="dark"] .nav-link:hover {
  color: var(--text-primary);
  background-color: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .nav-link.active {
  color: var(--text-primary);
  background-color: rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .dropdown-panel {
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.25);
}

[data-theme="dark"] .dropdown-link:hover {
  background-color: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .dropdown-link-title {
  color: var(--text-primary);
}

[data-theme="dark"] .dropdown-link-desc {
  color: rgba(255, 255, 255, 0.45);
}

[data-theme="dark"] .lang-option {
  color: rgba(255, 255, 255, 0.45);
}

[data-theme="dark"] .lang-separator {
  color: rgba(255, 255, 255, 0.2);
}

[data-theme="dark"] .github-link {
  color: rgba(255, 255, 255, 0.6);
}

[data-theme="dark"] .github-link:hover {
  color: var(--text-primary);
  background-color: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .mobile-menu-toggle {
  color: var(--text-primary);
}

[data-theme="dark"] .mobile-menu-toggle:hover {
  background-color: rgba(255, 255, 255, 0.06);
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border-light);
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  cursor: pointer;
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--border-medium);
  color: var(--text-primary);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

.theme-icon-moon {
  display: none;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .site-header {
    border-bottom-color: rgba(255, 255, 255, 0.06);
  }
  :root:not([data-theme="light"]) .logo,
  :root:not([data-theme="light"]) .logo-text {
    color: #E8E6E3;
  }
  :root:not([data-theme="light"]) .logo-tagline {
    color: rgba(255, 255, 255, 0.38);
    border-left-color: rgba(255, 255, 255, 0.1);
  }
  :root:not([data-theme="light"]) .nav-link {
    color: #E8E6E3;
  }
  :root:not([data-theme="light"]) .nav-link:hover {
    color: #E8E6E3;
    background-color: rgba(255, 255, 255, 0.06);
  }
  :root:not([data-theme="light"]) .dropdown-link:hover {
    background-color: rgba(255, 255, 255, 0.06);
  }
  :root:not([data-theme="light"]) .dropdown-link-title {
    color: #E8E6E3;
  }
  :root:not([data-theme="light"]) .dropdown-link-desc {
    color: rgba(255, 255, 255, 0.45);
  }
  :root:not([data-theme="light"]) .lang-option {
    color: rgba(255, 255, 255, 0.45);
  }
  :root:not([data-theme="light"]) .lang-separator {
    color: rgba(255, 255, 255, 0.2);
  }
  :root:not([data-theme="light"]) .github-link {
    color: rgba(255, 255, 255, 0.6);
  }
  :root:not([data-theme="light"]) .github-link:hover {
    color: #E8E6E3;
    background-color: rgba(255, 255, 255, 0.06);
  }
  :root:not([data-theme="light"]) .mobile-menu-toggle {
    color: #E8E6E3;
  }
  :root:not([data-theme="light"]) .theme-icon-sun {
    display: none;
  }
  :root:not([data-theme="light"]) .theme-icon-moon {
    display: block;
  }
}