.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 100;
  border-block-end: 1px solid var(--color-border-dark);
  background: var(--color-ink);
  color: var(--color-mist);
}

.site-header__inner {
  display: flex;
  align-items: center;
  min-block-size: 4.5rem;
  gap: var(--space-3);
}

.site-header__brand {
  display: inline-flex;
  flex: 0 1 auto;
  align-items: center;
  gap: var(--space-3);
  min-inline-size: 0;
  color: var(--color-mist);
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1;
  text-decoration: none;
}

.site-header__brand:hover { color: var(--color-mist); }

.site-header__mark {
  flex: 0 0 auto;
  inline-size: 2rem;
  block-size: 2rem;
  object-fit: contain;
}

.site-header__brand-text {
  min-inline-size: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.site-header__toggle {
  display: inline-grid;
  place-content: center;
  gap: 0.25rem;
  flex: 0 0 auto;
  inline-size: 2.75rem;
  min-block-size: 2.75rem;
  margin-inline-start: auto;
  padding: 0.625rem;
  border: 1px solid var(--color-border-dark);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-mist);
}

.site-header__toggle:hover,
.site-header__toggle[aria-expanded="true"] {
  border-color: var(--color-amber);
  background: transparent;
  color: var(--color-amber);
}

.site-header__toggle-line {
  display: block;
  inline-size: 1.25rem;
  block-size: 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__navigation {
  position: absolute;
  inset-block-start: calc(100% + 1px);
  inset-inline: 0;
  display: grid;
  gap: var(--space-5);
  max-block-size: calc(100dvh - 4.5rem);
  padding: var(--space-5) var(--gutter);
  overflow-y: auto;
  border-block-end: 1px solid var(--color-border-dark);
  background: var(--color-ink-raised);
  box-shadow: var(--shadow-floating);
  opacity: 0;
  pointer-events: none;
  transform: translateY(-0.5rem);
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.site-header__navigation.is-open {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.site-header__nav-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-header__nav-list li,
.site-header__nav-list li + li { margin: 0; }

.site-header__nav-link {
  display: flex;
  align-items: center;
  min-block-size: 2.75rem;
  border-block-end: 1px solid var(--color-border-dark);
  color: var(--color-mist);
  font-family: var(--font-heading);
  font-size: var(--text-caption);
  font-weight: 500;
  line-height: 1.2;
  text-decoration: none;
}

.site-header__nav-link:hover,
.site-header__nav-link[aria-current="page"] {
  color: var(--color-amber);
  box-shadow: inset 3px 0 0 var(--color-amber);
  padding-inline-start: var(--space-3);
}

.site-header__play-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-block-size: 2.75rem;
  padding: 0.75rem 1.125rem;
  border: 1px solid var(--color-amber);
  border-radius: var(--radius-sm);
  background: var(--color-amber);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-caption);
  font-weight: 600;
  line-height: 1.15;
  text-align: center;
  text-decoration: none;
}

.site-header__play-link:hover { background: transparent; color: var(--color-amber); }

@media (min-width: 72rem) {
  .site-header__inner { min-block-size: 4.75rem; gap: var(--space-5); }
  .site-header__mark { inline-size: 2.5rem; block-size: 2.5rem; }
  .site-header__brand { font-size: 1.0625rem; }
  .site-header__toggle { display: none; }
  .site-header__navigation {
    position: static;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: var(--space-4);
    flex: 1 1 auto;
    max-block-size: none;
    min-inline-size: 0;
    padding: 0;
    overflow: visible;
    border: 0;
    background: transparent;
    box-shadow: none;
    opacity: 1;
    pointer-events: auto;
    transform: none;
  }
  .site-header__nav-list {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    min-inline-size: 0;
  }
  .site-header__nav-item--mobile { display: none; }
  .site-header__nav-link {
    min-block-size: 4.75rem;
    border: 0;
    font-size: 0.8125rem;
    white-space: nowrap;
  }
  .site-header__nav-link:hover,
  .site-header__nav-link[aria-current="page"] {
    padding-inline-start: 0;
    box-shadow: inset 0 -3px 0 var(--color-amber);
  }
  .site-header__play-link { flex: 0 0 auto; white-space: nowrap; }
}

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