/* ============================================
   KOREA DECODE — Layout CSS
   Header, Footer, Navigation, Grid
   ============================================ */

/* --- Header --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(0, 0, 0, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: transform var(--transition);
}

.site-header.hidden {
  transform: translateY(-100%);
}

.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-lg);
}

.site-logo {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

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

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

.site-nav a {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: color var(--transition-fast);
  position: relative;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--accent);
}

.site-nav a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-sm);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: var(--transition);
}

.menu-toggle.open span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.menu-toggle.open span:nth-child(2) {
  opacity: 0;
}
.menu-toggle.open span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Footer --- */
.site-footer {
  background: var(--bg-sec);
  border-top: 1px solid var(--border);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

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

.footer-brand {
  max-width: 300px;
}

.footer-brand .site-logo {
  font-size: 1.2rem;
  margin-bottom: var(--space-md);
  display: inline-block;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-section h4 {
  font-family: var(--font-body);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

.footer-section a {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}

.footer-section a:hover {
  color: var(--accent);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-xl);
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- Page Content Offset --- */
.page-content {
  padding-top: var(--header-height);
  min-height: 100vh;
}

/* --- Grid System --- */
.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* --- Responsive --- */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root {
    --header-height: 56px;
  }

  .menu-toggle {
    display: flex;
  }

  .site-nav {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    background: rgba(0, 0, 0, 0.98);
    padding: var(--space-2xl) var(--space-lg);
    gap: var(--space-xl);
    z-index: 999;
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a {
    font-size: 1.2rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}