.site-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background-color: var(--color-bg);
  transition: transform 0.25s ease;
  display: flex;
  align-items: baseline;
  gap: var(--space-xl);
  padding-top: var(--space-l);
  padding-bottom: var(--space-l);
  /* Break out of body's left padding so nav starts at x=0 (viewport left edge).
     Right side stays at body's right content edge — the ::after handles the
     full-bleed border. */
  margin-inline: calc(-1 * var(--site-padding));
  padding-inline: calc(var(--site-padding) + max(0px, (100% - var(--content-width)) / 2));
  flex-wrap: wrap;
  row-gap: var(--space-s);
}

.site-nav::after {
  content: '';
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: var(--border-weight);
  background: transparent;
  transition: background-color 0.2s ease;
  pointer-events: none;
}

.site-nav[data-scrolled]::after {
  background: var(--color-text);
}

.site-nav[data-nav-hidden] {
  transform: translateY(-100%);
}

.nav-wordmark {
  font-size: var(--text-wordmark);
  font-weight: 700;
  letter-spacing: var(--tracking-tight);
  text-decoration: none;
  color: var(--color-text);
  transition: var(--transition);
  flex-shrink: 0;
}

.nav-wordmark:visited {
  color: var(--color-text);
}

.nav-wordmark:hover,
.nav-wordmark[aria-current="page"] {
  color: var(--color-accent);
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-l);
  row-gap: var(--space-s);
  flex: 0 0 100%; /* narrow default: own row, after wordmark + toggle */
}


.site-nav ul a {
  font-size: max(1rem, var(--text-sm)); /* floor at 16px on mobile */
  font-weight: 400;
  letter-spacing: var(--tracking-normal);
  text-transform: capitalize;
  text-decoration: none;
  color: var(--color-muted);
  transition: var(--transition);
}

.site-nav ul a:visited {
  color: var(--color-muted);
}

.site-nav ul a:hover,
.site-nav ul a[aria-current="page"] {
  color: var(--color-text);
}

.site-nav ul a[aria-current="page"] {
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
  text-underline-offset: 0.25em;
  text-decoration-thickness: 2px;
}

/* Theme toggle — positioned at the trailing end of the nav */
.theme-toggle {
  margin-left: auto;
  appearance: none;
  background: none;
  border: none;
  /* WCAG 2.5.5: minimum 44×44px touch target */
  padding: var(--space-s);
  min-width: 2.75rem;
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--color-muted);
  cursor: pointer;
  transition: var(--transition);
  flex-shrink: 0;
}

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

.theme-toggle:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}