.site-header {
  position: relative;
  z-index: 1000;
  background-color: var(--color-paper);
  border-bottom: 2px solid var(--color-navy);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  width: 100%;
  max-width: var(--container-wide);
  margin-inline: auto;
  padding-inline: var(--container-pad-mobile);
  min-height: 64px;
}

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

.site-header__logo {
  width: 44px;
  height: 44px;
  object-fit: contain;
  display: block;
}

.site-header__wordmark {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.site-header__toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 2px solid var(--color-navy);
  border-radius: var(--radius-button-rect);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.site-header__toggle:hover {
  background-color: var(--color-paper-deep);
}

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

.site-header__toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-navy);
  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: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background-color: var(--color-paper);
  border-bottom: 2px solid var(--color-navy);
  box-shadow: var(--shadow-soft);
  max-height: calc(100vh - 64px);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

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

.site-header__nav-list {
  list-style: none;
  margin: 0;
  padding: var(--space-md) var(--container-pad-mobile);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

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

.site-header__nav-link {
  display: block;
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-body);
  font-size: var(--text-body);
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-navy);
  text-decoration: none;
  border-radius: var(--radius-button-rect);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.site-header__nav-link:hover {
  background-color: var(--color-paper-deep);
}

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

@media (min-width: 768px) {
  .site-header__inner {
    padding-inline: var(--container-pad-tablet);
  }

  .site-header__nav-list {
    padding-inline: var(--container-pad-tablet);
  }
}

@media (min-width: 1024px) {
  .site-header__inner {
    padding-inline: var(--container-pad-desktop);
    min-height: 72px;
  }

  .site-header__logo {
    width: 44px;
    height: 44px;
  }

  .site-header__toggle {
    display: none;
  }

  .site-header__nav {
    display: block;
    position: static;
    background-color: transparent;
    border-bottom: none;
    box-shadow: none;
    max-height: none;
    overflow-y: visible;
  }

  .site-header__nav-list {
    flex-direction: row;
    align-items: center;
    gap: var(--space-lg);
    padding: 0;
  }

  .site-header__nav-link {
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--text-small);
    font-weight: 600;
    line-height: 1.2;
    white-space: nowrap;
  }

  .site-header__nav-link:hover {
    background-color: transparent;
    color: var(--color-cornflower-deep);
  }

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