/* ==========================================================================
   Layout — Header, Footer, Grid
   ========================================================================== */

/* ---- Site Header / Nav ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background-color: var(--color-bg-dark);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.site-logo {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  color: var(--color-white);
  text-decoration: none;
  white-space: nowrap;
}

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

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

.main-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.main-nav__item {
  position: relative;
}

.main-nav__link {
  display: block;
  padding: var(--space-sm) var(--space-md);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: rgba(255, 255, 255, 0.8);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.main-nav__link:hover,
.main-nav__link--active {
  color: var(--color-white);
  background-color: rgba(255, 255, 255, 0.1);
}

.main-nav__link--icon {
  display: flex;
  align-items: center;
  justify-content: center;
}

.main-nav__link--icon svg {
  display: block;
}

/* Dropdown */
.main-nav__dropdown-toggle {
  cursor: pointer;
}

.main-nav__dropdown-toggle::after {
  content: '';
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: 6px;
  vertical-align: middle;
  border-top: 5px solid currentColor;
  border-right: 4px solid transparent;
  border-left: 4px solid transparent;
}

.main-nav__dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  padding: var(--space-sm) 0;
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-dropdown);
}

.main-nav__item:hover .main-nav__dropdown,
.main-nav__item--open .main-nav__dropdown {
  display: block;
}

.main-nav__dropdown-link {
  display: block;
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  transition: background-color var(--transition-fast);
}

.main-nav__dropdown-link:hover {
  background-color: var(--color-bg-alt);
  color: var(--color-primary);
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 12px;
  min-width: 48px;
  min-height: 48px;
}

.nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-white);
  margin: 5px 0;
  transition: transform var(--transition-base), opacity var(--transition-base);
  border-radius: 2px;
}

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

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

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

.grid--auto-fill {
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

/* ---- Site Footer ---- */
.site-footer {
  background-color: var(--color-bg-footer);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.site-footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--space-2xl);
}

.site-footer__brand {
  max-width: 300px;
}

.site-footer__brand-name {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  color: var(--color-white);
  margin-bottom: var(--space-sm);
}

.site-footer__links {
  display: flex;
  gap: var(--space-3xl);
}

.site-footer__col-title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-white);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-md);
}

.site-footer__col a {
  display: block;
  padding: var(--space-xs) 0;
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.site-footer__col a:hover {
  color: var(--color-accent);
}

.site-footer__bottom {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.site-footer__copyright {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.5);
}

.site-footer__social {
  display: flex;
  gap: var(--space-md);
}

.site-footer__social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background-color: rgba(255, 255, 255, 0.1);
  color: var(--color-white);
  transition: background-color var(--transition-fast);
}

.site-footer__social a:hover {
  background-color: var(--color-primary);
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .main-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background-color: var(--color-bg-dark);
    padding: var(--space-lg);
    box-shadow: var(--shadow-lg);
  }

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

  .main-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .main-nav__link {
    padding: var(--space-md);
  }

  .main-nav__dropdown {
    position: static;
    box-shadow: none;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-sm);
    margin-top: var(--space-xs);
  }

  .main-nav__dropdown-link {
    color: rgba(255, 255, 255, 0.7);
    padding: var(--space-sm) var(--space-xl);
  }

  .main-nav__dropdown-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--color-white);
  }

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

  .site-footer__inner {
    flex-direction: column;
  }

  .site-footer__links {
    flex-direction: column;
    gap: var(--space-xl);
  }

  .site-footer__bottom {
    flex-direction: column;
    text-align: center;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

/* Extra-small screens */
@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  .site-footer {
    padding: var(--space-2xl) 0 var(--space-lg);
  }
}