/*
 * layout.css — Site shell: header, nav, footer, page containers
 */

/* ── Site header ─────────────────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(13, 17, 23, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

/* ── Logo ────────────────────────────────────────────────────────────────── */
.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
  font-weight: 700;
  font-size: var(--text-lg);
  letter-spacing: -0.02em;
  text-decoration: none;
  flex-shrink: 0;
}

.site-logo:hover {
  color: var(--color-text);
  text-decoration: none;
}

.site-logo__mark {
  width: 28px;
  height: 28px;
  background: var(--color-accent);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
  font-weight: 800;
  color: #0d1117;
  flex-shrink: 0;
}

/* ── Primary nav ─────────────────────────────────────────────────────────── */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.site-nav__link {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.site-nav__link:hover,
.site-nav__link[aria-current="page"],
.site-nav__link.is-active {
  color: var(--color-text);
  background: var(--color-surface);
  text-decoration: none;
}

.site-nav__link--cta {
  background: var(--color-accent);
  color: #0d1117 !important;
  font-weight: 600;
  padding: var(--space-2) var(--space-4);
}

.site-nav__link--cta:hover {
  background: var(--color-accent-hover);
  color: #0d1117 !important;
  text-decoration: none;
}

/* ── Mobile nav toggle ───────────────────────────────────────────────────── */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: var(--space-2);
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  flex-shrink: 0;
}

.nav-toggle__bar {
  display: block;
  height: 2px;
  background: var(--color-text-muted);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-fast);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── Mobile drawer ───────────────────────────────────────────────────────── */
.mobile-nav {
  display: none;
  position: fixed;
  inset: var(--header-height) 0 0 0;
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  padding: var(--space-6);
  z-index: 99;
  overflow-y: auto;
}

.mobile-nav.is-open {
  display: block;
}

.mobile-nav__link {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: var(--space-1);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.mobile-nav__link:hover {
  color: var(--color-text);
  background: var(--color-surface);
  text-decoration: none;
}

/* ── Page container ──────────────────────────────────────────────────────── */
.page {
  min-height: calc(100vh - var(--header-height));
}

/* ── Site footer ─────────────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-12) var(--space-6);
  margin-top: var(--space-20);
}

.site-footer__inner {
  max-width: var(--content-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-8);
}

.site-footer__brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.site-footer__tagline {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}

.site-footer__heading {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-3);
}

.site-footer__links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.site-footer__links a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.site-footer__links a:hover {
  color: var(--color-text);
}

.site-footer__bottom {
  max-width: var(--content-width);
  margin: var(--space-10) auto 0;
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border-muted);
  font-size: var(--text-sm);
  color: var(--color-text-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* ── Responsive ──────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .site-nav {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

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

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}