/* Layout — Header, Footer, Nav, Grid, Containers */

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Section spacing */
.section {
  padding: var(--space-16) 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-2);
  text-align: center;
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  text-align: center;
  max-width: 640px;
  margin: 0 auto var(--space-12);
}

/* ─── Header ─── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  height: var(--header-height);
  transition: box-shadow var(--transition-base);
}

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: 700;
  font-size: var(--text-xl);
  color: var(--text);
}

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

.logo img {
  height: 40px;
  width: auto;
}

/* ─── Nav ─── */
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-links a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  padding: var(--space-2) 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition-base);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}

.nav-links a.active::after,
.nav-links a:hover::after {
  width: 100%;
}

/* Theme toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  transition: background var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--bg-alt);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  color: var(--text-secondary);
}

/* Mobile hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  margin: 0 auto;
  transition: transform var(--transition-base), opacity var(--transition-fast);
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ─── Footer ─── */
.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: var(--space-12) 0 var(--space-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-8);
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: var(--text-sm);
  margin-top: var(--space-3);
  max-width: 320px;
}

.footer-heading {
  font-size: var(--text-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: var(--space-6);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-bottom p {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* ─── Grid utilities ─── */
.grid {
  display: grid;
  gap: var(--space-6);
}

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

@media (max-width: 768px) {
  .section {
    padding: var(--space-12) 0;
  }

  .section-title {
    font-size: var(--text-2xl);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

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

  /* Mobile nav */
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    background: var(--bg);
    padding: var(--space-8);
    gap: var(--space-4);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    z-index: 99;
  }

  .nav-links.open {
    transform: translateX(0);
  }

  .nav-links a {
    font-size: var(--text-lg);
  }
}