/* ============================================================
   NAVIGATION
   ============================================================ */

#site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}
#site-nav.scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
  padding-block: var(--space-4);
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  flex-shrink: 0;
}
.nav-logo-mark {
  width: 40px;
  height: 40px;
}
.nav-logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}
.nav-logo-title {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.nav-logo-sub {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.03em;
}

/* Links */
#nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
}
#nav-menu a {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
}
#nav-menu a:hover,
#nav-menu a.active {
  color: var(--color-accent);
  background: var(--color-accent-light);
}
#nav-menu a.active { font-weight: 600; }

/* Nav right controls */
.nav-controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}
[data-theme-toggle] {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: color var(--transition), background var(--transition);
}
[data-theme-toggle]:hover { color: var(--color-text); background: var(--color-surface-2); }

/* Mobile hamburger */
#menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  color: var(--color-text);
  cursor: pointer;
}

/* ============================================================
   FOOTER
   ============================================================ */

.site-footer {
  background: var(--color-accent);
  color: rgba(255,255,255,0.85);
  padding-block: var(--space-16) var(--space-8);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}
.footer-brand-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: #fff;
  margin-bottom: var(--space-3);
}
.footer-brand-desc {
  font-size: var(--text-sm);
  line-height: 1.7;
  max-width: 32ch;
  color: rgba(255,255,255,0.7);
}
.footer-col-title {
  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-links { list-style: none; display: flex; flex-direction: column; gap: var(--space-2); }
.footer-links a {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.75);
  text-decoration: none;
  transition: color var(--transition);
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.5);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 700px) {
  #nav-menu {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4);
    box-shadow: var(--shadow-md);
  }
  #nav-menu.open { display: flex; }
  #nav-menu a { width: 100%; padding: var(--space-3) var(--space-4); }
  #menu-toggle { display: flex; }
  #site-nav { position: sticky; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
}