.site-header {
  position: relative;
  z-index: 1000;
  background-color: var(--color-warm-ivory);
  border-bottom: 1px solid var(--color-border-light);
}

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

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

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

.site-header__logo {
  width: 56px;
  height: 56px;
  object-fit: contain;
  display: block;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.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;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}

.site-header__toggle:hover {
  background-color: rgba(31, 97, 141, 0.08);
}

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

.site-header__toggle-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-cobalt-blue);
  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: 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-list li {
  margin: 0;
  padding: 0;
}

.site-header__nav-list a {
  display: inline-block;
  padding: var(--space-2) 0;
  font-size: var(--text-body-size);
  font-weight: 500;
  line-height: 1.2;
  color: var(--color-text-on-light);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition-fast);
}

.site-header__nav-list a:hover {
  color: var(--color-tomato-red);
}

.site-header__nav-list a:focus-visible {
  outline: 2px solid var(--color-focus-ring);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

@media (max-width: 64rem) {
  .site-header__inner {
    flex-wrap: wrap;
    min-height: 64px;
  }

  .site-header__brand-text {
    font-size: 1.125rem;
  }

  .site-header__logo {
    width: 48px;
    height: 48px;
  }

  .site-header__toggle {
    display: flex;
  }

  .site-header__nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-dark-berry);
    border-bottom: 1px solid var(--color-border-dark);
    box-shadow: var(--shadow-lg);
    max-height: calc(100vh - 64px);
    overflow-y: auto;
    display: none;
    padding: var(--space-3) var(--container-padding);
    z-index: 999;
  }

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

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

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

  .site-header__nav-list a {
    display: block;
    padding: var(--space-3) var(--space-2);
    color: var(--color-text-on-dark);
    border-bottom: 1px solid var(--color-border-dark);
    font-size: var(--text-body-large-size);
  }

  .site-header__nav-list a:hover {
    color: var(--color-butter-yellow);
    background-color: rgba(253, 242, 233, 0.06);
  }

  .site-header__nav-list a:focus-visible {
    outline-color: var(--color-butter-yellow);
  }
}

@media (max-width: 36rem) {
  .site-header__inner {
    min-height: 56px;
  }

  .site-header__logo {
    width: 40px;
    height: 40px;
  }

  .site-header__brand-text {
    font-size: 1rem;
  }

  .site-header__nav {
    max-height: calc(100vh - 56px);
  }
}