.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--color-volcanic-charcoal);
  border-bottom: var(--border-dark);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding: var(--space-3) var(--container-padding-mobile);
  min-height: 64px;
}

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

.site-header__logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  flex-shrink: 0;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.site-header__toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-warm-ivory);
  flex-shrink: 0;
}

.site-header__toggle-icon,
.site-header__toggle-icon::before,
.site-header__toggle-icon::after {
  display: block;
  width: 24px;
  height: 2px;
  background-color: currentColor;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
  content: "";
}

.site-header__toggle-icon {
  position: relative;
}

.site-header__toggle-icon::before {
  position: absolute;
  top: -7px;
  left: 0;
}

.site-header__toggle-icon::after {
  position: absolute;
  top: 7px;
  left: 0;
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-icon {
  background-color: transparent;
}

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

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

.site-header__nav {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background-color: var(--color-volcanic-charcoal);
  border-bottom: var(--border-dark);
  max-height: calc(100vh - 64px);
  overflow-y: auto;
  padding: var(--space-4) var(--container-padding-mobile);
  z-index: 999;
}

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

.site-header__nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin: 0;
  padding: 0;
  list-style: none;
}

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

.site-header__nav-link {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-small-size);
  letter-spacing: 0.02em;
  color: var(--color-warm-ivory);
  text-decoration: none;
  transition: color var(--transition-fast), background-color var(--transition-fast);
  border-radius: var(--radius-subtle);
}

.site-header__nav-link:hover {
  color: var(--color-teal-muted);
  background-color: rgba(31, 78, 74, 0.1);
}

.site-header__nav-link:focus-visible {
  outline: var(--focus-outline);
  outline-offset: var(--focus-offset);
}

@media (min-width: 768px) {
  .site-header__inner {
    padding: var(--space-3) var(--container-padding-desktop);
    min-height: 72px;
  }

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

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

  .site-header__toggle {
    display: none;
  }

  .site-header__nav {
    display: block;
    position: static;
    background: none;
    border: none;
    max-height: none;
    overflow: visible;
    padding: 0;
  }

  .site-header__nav-list {
    flex-direction: row;
    align-items: center;
    gap: var(--space-4);
  }

  .site-header__nav-link {
    padding: var(--space-2) 0;
    border-bottom: 2px solid transparent;
    border-radius: 0;
  }

  .site-header__nav-link:hover {
    background: none;
    border-bottom-color: var(--color-deep-teal);
  }
}

@media (min-width: 1024px) {
  .site-header__nav-list {
    gap: var(--space-5);
  }
}

@media (max-width: 767px) {
  .site-header__inner {
    min-height: 56px;
  }

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

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

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