/* ============================================================
   layout.css — Header, Footer, Navigation, Grid Layouts
   ============================================================ */

/* === Header === */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  height: var(--header-height);
  background-color: var(--color-bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: background-color var(--transition-base);
}

.site-header.scrolled {
  background-color: rgba(10, 10, 10, 0.96);
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

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

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-text-primary);
  letter-spacing: -0.02em;
  flex-shrink: 0;
}

.logo-icon {
  width: 36px;
  height: 36px;
  color: var(--color-gold-400);
}

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

.nav-link {
  padding: 0.5rem 0.85rem;
  font-size: var(--text-small);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background-color: var(--color-gold-400);
  border-radius: 1px;
}

/* Nav Item — uniform wrapper for all top-level nav items */
.nav-item {
  position: relative;
}

/* Dropdown arrow inside nav-link — override main.css svg { display: block } */
.dropdown-arrow {
  display: inline-block;
  vertical-align: middle;
  margin-left: 0.3rem;
}

/* Dropdown */
.nav-dropdown {
  position: relative;
}

.nav-dropdown__menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-sm);
  min-width: 220px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-lg);
}

.nav-dropdown:hover .nav-dropdown__menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(4px);
}

.nav-dropdown__link {
  display: block;
  padding: 0.6rem 1rem;
  font-size: var(--text-small);
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-dropdown__link:hover {
  color: var(--color-text-primary);
  background-color: rgba(255, 255, 255, 0.04);
}

/* Header CTA */
.header-cta {
  flex-shrink: 0;
}

/* Mobile Menu Toggle */
.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
  cursor: pointer;
  z-index: calc(var(--z-overlay) + 10);
}

.mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text-primary);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.mobile-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-toggle.active span:nth-child(2) {
  opacity: 0;
}

.mobile-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  z-index: var(--z-overlay);
  background-color: var(--color-bg-primary);
  padding: calc(var(--header-height) + var(--space-lg)) var(--space-md) var(--space-lg);
  overflow-y: auto;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.mobile-menu.open {
  opacity: 1;
  visibility: visible;
}

.mobile-menu .nav-link {
  display: block;
  padding: 0.85rem 0;
  font-size: var(--text-body);
  border-bottom: 1px solid var(--color-border);
}

.mobile-menu .btn {
  margin-top: var(--space-md);
  width: 100%;
}

/* === Footer === */
.site-footer {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: var(--space-xl);
  padding-bottom: var(--space-xl);
}

.footer-col h4 {
  font-size: var(--text-small);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-col a {
  font-size: var(--text-small);
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-gold-400);
}

.footer-description {
  font-size: var(--text-small);
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
  line-height: 1.6;
}

.footer-certifications {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-sm);
}

.footer-cert-badge {
  width: 48px;
  height: 48px;
  background-color: var(--color-bg-tertiary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: var(--text-caption);
  font-weight: 600;
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-caption);
  color: var(--color-text-muted);
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.footer-bottom-links {
  display: flex;
  gap: var(--space-md);
}

.footer-bottom-links a {
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

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

.social-links {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-sm);
}

.social-link {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--color-bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  transition: all var(--transition-fast);
}

.social-link:hover {
  background-color: var(--color-gold-400);
  color: var(--color-bg-primary);
}

/* === Back to Top === */
.back-to-top {
  position: fixed;
  bottom: var(--space-lg);
  right: var(--space-lg);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  z-index: var(--z-dropdown);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  cursor: pointer;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  border-color: var(--color-gold-400);
  color: var(--color-gold-400);
  transform: translateY(-2px);
}

/* === Image Placeholder === */
.img-placeholder {
  background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: var(--text-caption);
  text-align: center;
  overflow: hidden;
  position: relative;
}

.img-placeholder::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center, rgba(229, 168, 48, 0.05) 0%, transparent 70%);
  pointer-events: none;
}