.site-header {
  position: relative;
  z-index: 50;
  width: 100%;
  border-bottom: 1px solid var(--color-line-subtle);
  background: var(--color-ink-900);
}

.site-header__inner {
  display: flex;
  min-height: 4.75rem;
  align-items: center;
  gap: var(--space-5);
}

.site-header__brand {
  display: inline-flex;
  min-width: 0;
  flex: 0 1 auto;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text-primary);
  text-decoration: none;
}

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

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

.site-header__brand-copy {
  display: grid;
  min-width: 0;
  gap: 0.0625rem;
}

.site-header__brand-name {
  overflow: hidden;
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.1;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.site-header__brand-tagline {
  color: var(--color-text-secondary);
  font-size: var(--font-size-12);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.site-header__toggle {
  display: none;
  width: 2.75rem;
  min-width: 2.75rem;
  height: 2.75rem;
  margin-left: auto;
  padding: 0.625rem;
  border: 1px solid var(--color-line-strong);
  border-radius: var(--radius-card);
  background: transparent;
}

.site-header__toggle-line {
  display: block;
  width: 100%;
  height: 2px;
  margin: 0.1875rem 0;
  background: var(--color-text-primary);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(1) {
  transform: translateY(0.3125rem) 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(-0.3125rem) rotate(-45deg);
}

.site-header__nav {
  display: flex;
  min-width: 0;
  flex: 1 1 auto;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.site-header__nav-list {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: var(--space-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-header__nav-item,
.site-header__nav-item + .site-header__nav-item {
  display: flex;
  min-width: 0;
  margin: 0;
  padding: 0;
}

.site-header__nav-link,
.site-header__contact {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  border-bottom: 2px solid transparent;
  color: var(--color-text-secondary);
  font-size: var(--font-size-14);
  font-weight: 700;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.site-header__nav-link:hover,
.site-header__nav-link[aria-current="page"],
.site-header__contact:hover {
  border-bottom-color: var(--color-accent-saffron);
  color: var(--color-text-primary);
}

.site-header__actions {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: var(--space-3);
}

.site-header__download {
  flex: 0 0 auto;
  white-space: nowrap;
}

.site-header__nav-item--mobile {
  display: none;
}

@media (max-width: 1100px) {
  .site-header__inner {
    min-height: 4.5rem;
    gap: var(--space-3);
  }

  .site-header__toggle {
    display: block;
  }

  .site-header__nav {
    position: absolute;
    top: calc(100% + 1px);
    right: 0;
    left: 0;
    display: none;
    max-height: calc(100vh - 4.5rem);
    overflow-y: auto;
    padding: var(--space-4) max(var(--container-padding), env(safe-area-inset-right)) var(--space-5);
    border-bottom: 1px solid var(--color-line-subtle);
    background: var(--color-ink-900);
  }

  .site-header__nav.is-open {
    display: grid;
    gap: var(--space-4);
  }

  .site-header__nav-list {
    display: grid;
    gap: 0;
  }

  .site-header__nav-item,
  .site-header__nav-item--mobile {
    display: block;
    border-bottom: 1px solid var(--color-line-subtle);
  }

  .site-header__nav-link {
    width: 100%;
    min-height: 3rem;
    border-bottom: 0;
  }

  .site-header__nav-link:hover,
  .site-header__nav-link[aria-current="page"] {
    border-bottom-color: transparent;
    color: var(--color-accent-saffron);
  }

  .site-header__actions {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .site-header__contact {
    justify-content: center;
    border: 1px solid #718087;
    border-radius: var(--radius-card);
    color: var(--color-text-primary);
  }

  .site-header__contact:hover {
    border-color: var(--color-line-strong);
    background: var(--color-surface-700);
  }
}

@media (max-width: 560px) {
  .site-header__inner {
    min-height: 4rem;
  }

  .site-header__logo {
    width: 2rem;
    height: 2rem;
    flex-basis: 2rem;
  }

  .site-header__brand {
    gap: var(--space-2);
  }

  .site-header__brand-name {
    font-size: var(--font-size-16);
  }

  .site-header__brand-tagline {
    display: none;
  }

  .site-header__nav {
    max-height: calc(100vh - 4rem);
  }

  .site-header__actions {
    grid-template-columns: 1fr;
  }

  .site-header__download,
  .site-header__contact {
    width: 100%;
  }
}