.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: var(--color-paper);
  border-bottom: var(--border-thin);
}

body {
  padding-top: 72px;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: 72px;
  padding-block: var(--space-3);
}

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

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.2;
  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;
  cursor: pointer;
  flex-shrink: 0;
}

.site-header__toggle-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-ink);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.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__toggle:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-radius: var(--radius-small);
}

.site-header__nav {
  display: flex;
  align-items: center;
}

.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;
  padding: var(--space-2) var(--space-3);
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.2;
  color: var(--color-ink);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease;
}

.site-header__nav-link:hover {
  color: var(--color-clay);
}

.site-header__nav-link:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-radius: var(--radius-small);
}

@media (max-width: 63.9375rem) {
  .site-header__toggle {
    display: flex;
  }

  .site-header__nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    width: 100%;
    background-color: var(--color-paper);
    border-bottom: var(--border-thin);
    box-shadow: var(--shadow-soft);
    max-height: calc(100vh - 72px);
    overflow-y: auto;
    display: none;
    padding: var(--space-4);
  }

  .site-header__nav.is-open {
    display: flex;
    justify-content: center;
  }

  .site-header__nav.is-open .site-header__nav-list {
    width: 100%;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-2);
  }

  .site-header__nav-link {
    display: block;
    padding: var(--space-3);
    font-size: 1.125rem;
  }
}

@media (max-width: 47.9375rem) {
  .site-header__inner {
    min-height: 64px;
    padding-block: var(--space-2);
  }

  body {
    padding-top: 64px;
  }

  .site-header__logo {
    width: 32px;
    height: 32px;
  }

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

  .site-header__nav {
    max-height: calc(100vh - 64px);
  }
}