.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  width: 100%;
  border-block-end: 1px solid var(--colour-cobalt-deep);
  background: var(--colour-ivory-canvas);
  color: var(--colour-ink);
}

.site-header__inner {
  display: flex;
  min-height: 4.75rem;
  align-items: center;
  width: min(100% - (var(--gutter) * 2), var(--container-max));
  margin-inline: auto;
  gap: var(--space-4);
}

.site-header__brand {
  display: inline-flex;
  flex: 0 1 auto;
  align-items: center;
  min-width: 0;
  gap: 0.625rem;
  color: var(--colour-cobalt-deep);
  text-decoration: none;
}

.site-header__brand:hover { color: var(--colour-cobalt-primary); }

.site-header__mark {
  width: 2.5rem;
  height: 2.5rem;
  flex: 0 0 2.5rem;
  object-fit: contain;
}

.site-header__brand-text {
  color: currentColor;
  font-family: var(--font-heading);
  font-size: 0.875rem;
  letter-spacing: -0.055em;
  line-height: 0.94;
  white-space: nowrap;
}

.site-header__nav {
  min-width: 0;
  margin-inline-start: auto;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0;
  gap: clamp(0.75rem, 1.5vw, 1.5rem);
  list-style: none;
}

.site-header__nav-list li,
.site-header__nav-list li + li {
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0;
}

.site-header__nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  color: var(--colour-ink);
  font-size: var(--text-utility);
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
}

.site-header__nav-link:hover,
.site-header__nav-link[aria-current="page"] {
  color: var(--colour-cobalt-primary);
}

.site-header__nav-link[aria-current="page"] {
  box-shadow: inset 0 -2px 0 var(--colour-cherry-accent);
}

.site-header__action {
  flex: 0 0 auto;
  margin-inline-start: var(--space-2);
  white-space: nowrap;
}

.site-header__toggle,
.site-header__mobile-context {
  display: none;
}

@media (max-width: 68rem) {
  .site-header__inner {
    min-height: 4.25rem;
    gap: var(--space-3);
  }

  .site-header__mark {
    width: 2.125rem;
    height: 2.125rem;
    flex-basis: 2.125rem;
  }

  .site-header__brand-text { font-size: 0.8125rem; }

  .site-header__toggle {
    display: inline-flex;
    width: 2.75rem;
    height: 2.75rem;
    flex: 0 0 2.75rem;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.25rem;
    margin-inline-start: auto;
    padding: 0;
    border: 1px solid var(--colour-cobalt-deep);
    border-radius: var(--radius-control);
    background: var(--colour-ivory-paper);
    color: var(--colour-cobalt-deep);
  }

  .site-header__toggle-line {
    display: block;
    width: 1.125rem;
    height: 2px;
    background: currentColor;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
  }

  .site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(1) { transform: translateY(0.375rem) rotate(45deg); }
  .site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(2) { opacity: 0; }
  .site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(3) { transform: translateY(-0.375rem) rotate(-45deg); }

  .site-header__nav {
    position: absolute;
    z-index: 101;
    top: 100%;
    right: var(--gutter);
    left: var(--gutter);
    display: none;
    max-height: calc(100vh - 4.25rem);
    overflow-y: auto;
    border: 1px solid var(--colour-cobalt-deep);
    background: var(--colour-ivory-paper);
    box-shadow: var(--shadow-raised);
  }

  .site-header__nav.is-open { display: block; }

  .site-header__nav-list {
    display: grid;
    align-items: stretch;
    gap: 0;
    padding: var(--space-3) var(--space-4);
  }

  .site-header__nav-list li,
  .site-header__nav-list li + li {
    display: block;
    border-block-end: var(--border);
  }

  .site-header__nav-list li:last-child { border-block-end: 0; }

  .site-header__nav-link {
    width: 100%;
    min-height: 3rem;
    font-size: 1rem;
  }

  .site-header__nav-link[aria-current="page"] { box-shadow: none; }

  .site-header__mobile-context {
    display: grid;
    gap: var(--space-2);
    margin: 0;
    padding: var(--space-4);
    border-block-start: 2px solid var(--colour-cherry-accent);
    background: var(--colour-cobalt-deep);
    color: var(--colour-ivory-canvas);
    font-size: var(--text-utility);
  }

  .site-header__mobile-context p { margin: 0; }
  .site-header__mobile-context a { color: var(--colour-ivory-canvas); font-weight: 700; }
}

@media (max-width: 30rem) {
  .site-header__brand-text { font-size: 0.75rem; }
  .site-header__action { padding-inline: 0.625rem; font-size: 0.75rem; }
}

@media (prefers-reduced-motion: reduce) {
  .site-header__toggle-line { transition: none; }
}