/* ============================================================
   LAYOUT — Header, Nav, Footer, Shared Components
   ============================================================ */

/* ---- HEADER ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in oklab, var(--color-bg) 92%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.site-header.scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
  padding-block: var(--space-4);
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-5), 5vw, var(--space-16));
}

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

.logo-mark {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.logo-name {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
}

.logo-tagline {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 400;
  letter-spacing: 0.04em;
}

/* Nav */
.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  list-style: none;
}

.nav-menu a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding-block: var(--space-1);
  border-bottom: 2px solid transparent;
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* Theme toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  transition: background var(--transition-interactive), color var(--transition-interactive);
}

.theme-toggle:hover {
  background: var(--color-surface-offset);
  color: var(--color-text);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

/* ---- FOOTER ---- */
.site-footer {
  background: var(--color-secondary);
  color: rgba(255,255,255,0.85);
  padding-block: clamp(var(--space-12), 6vw, var(--space-20));
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: clamp(var(--space-8), 4vw, var(--space-16));
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-5), 5vw, var(--space-16));
}

.footer-brand p {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.6);
  margin-top: var(--space-4);
  max-width: 28ch;
}

.footer-logo-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: #fff;
}

.footer-col h4 {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.5);
  margin-bottom: var(--space-4);
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer-col ul a {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.7);
  text-decoration: none;
}

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

.footer-bottom {
  margin-top: var(--space-12);
  padding-top: var(--space-6);
  border-top: 1px solid rgba(255,255,255,0.12);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-5), 5vw, var(--space-16));
}

.footer-bottom p, .footer-bottom a {
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.4);
}

.footer-bottom a:hover { color: rgba(255,255,255,0.8); }

/* ---- SCROLL REVEAL ---- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-reveal].revealed {
  opacity: 1;
  transform: none;
}

[data-reveal][data-delay="1"] { transition-delay: 0.1s; }
[data-reveal][data-delay="2"] { transition-delay: 0.2s; }
[data-reveal][data-delay="3"] { transition-delay: 0.3s; }
[data-reveal][data-delay="4"] { transition-delay: 0.4s; }

/* ---- RESPONSIVE ---- */
@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-10);
  }
}

@media (max-width: 640px) {
  .nav-menu {
    display: none;
    position: fixed;
    inset: 0;
    top: 68px;
    background: var(--color-bg);
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: var(--space-6);
    border-top: 1px solid var(--color-border);
    z-index: 99;
  }

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

  .nav-menu li { width: 100%; }

  .nav-menu a {
    display: block;
    padding: var(--space-4) 0;
    font-size: var(--text-base);
    border-bottom: 1px solid var(--color-divider);
  }

  .nav-toggle {
    display: flex;
  }

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

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