.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-paper);
  border-bottom: var(--border-width-thin) solid var(--color-border-light);
}

.site-header__inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-padding);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: 64px;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-ink);
  flex-shrink: 0;
}

.site-header__brand:hover {
  text-decoration: none;
}

.site-header__logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  display: block;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.5rem;
  line-height: 1.2;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  color: var(--color-ink);
}

.site-header__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: var(--radius-small);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.site-header__toggle:hover {
  background-color: rgba(54, 69, 79, 0.08);
}

.site-header__toggle:focus-visible {
  outline: 2px solid var(--color-cobalt);
  outline-offset: 2px;
}

.site-header__toggle-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-ink);
  border-radius: 1px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(1) {
  transform: translateY(7px) 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(-7px) rotate(-45deg);
}

.site-header__nav {
  display: block;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-header__nav-item {
  margin: 0;
  padding: 0;
}

.site-header__nav-link {
  display: inline-block;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.875rem;
  line-height: 1.5;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--color-ink);
  text-decoration: none;
  padding-block: var(--space-2);
  white-space: nowrap;
  transition: color var(--transition-fast);
}

.site-header__nav-link:hover {
  color: var(--color-crimson);
  text-decoration: none;
}

.site-header__nav-link:focus-visible {
  outline: 2px solid var(--color-cobalt);
  outline-offset: 2px;
  border-radius: var(--radius-small);
}

@media (max-width: 1023px) {
  .site-header__inner {
    flex-wrap: wrap;
    min-height: 56px;
  }

  .site-header__toggle {
    display: flex;
  }

  .site-header__nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-paper);
    border-bottom: var(--border-width-thin) solid var(--color-border-light);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
  }

  .site-header__nav.is-open {
    max-height: calc(100vh - 56px);
    overflow-y: auto;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-3) var(--container-padding);
  }

  .site-header__nav-item {
    border-bottom: var(--border-width-thin) solid var(--color-border-light);
  }

  .site-header__nav-item:last-child {
    border-bottom: none;
  }

  .site-header__nav-link {
    display: block;
    padding: var(--space-3) 0;
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .site-header__logo {
    width: 28px;
    height: 28px;
  }

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

  .site-header__inner {
    min-height: 48px;
  }

  .site-header__nav.is-open {
    max-height: calc(100vh - 48px);
  }
}