/* Site header: brand band above every page, with the main navigation. The
   brand is the monogram and the wordmark, ink with an accent "AI". The
   current page is marked by aria-current, in weight and underline, not colour
   alone. */

.site-header {
  background-color: var(--bg-surface);
  border-block-end: 1px solid var(--border-subtle);
  padding-block: var(--space-xs);
}

.site-header__brand {
  gap: var(--space-2xs);
  font-family: var(--font-display);
  font-size: var(--step-1);
  font-weight: 700;
  letter-spacing: var(--tracking-display);
  color: var(--text-primary);
  text-decoration: none;
}

.site-header__brand-ai {
  color: var(--accent);
}

.site-header__brand,
.site-header__link {
  display: inline-flex;
  align-items: center;
  min-block-size: var(--tap-min);
}

.site-header__nav ul {
  --cluster-space: var(--space-3xs) var(--space-m);
}

.site-header__link {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-standard);
}

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

.site-header__link:active {
  color: var(--accent);
}

.site-header__link[aria-current="page"] {
  color: var(--text-primary);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: var(--space-2xs);
}