/* Header styles */
.site-header {
  background-color: var(--color-background);
  border-bottom: 1px solid var(--color-neutral-200);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-identity .site-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-primary);
  margin: 0;
}

.logo-link {
  display: inline-block;
  transition: opacity var(--transition-duration-fast);
}

.logo-link:hover {
  opacity: 0.8;
}

.main-nav {
  display: flex;
  align-items: center;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  color: var(--color-text);
  font-size: var(--font-size-lg);
}

.hamburger {
  display: block;
  width: 1.5rem;
  height: 2px;
  background-color: var(--color-text);
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: '';
  display: block;
  width: 1.5rem;
  height: 2px;
  background-color: var(--color-text);
  position: absolute;
  transition: transform var(--transition-duration);
}

.hamburger::before {
  top: -6px;
}

.hamburger::after {
  top: 6px;
}

.nav-list {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--space-6);
}

.nav-link {
  font-weight: 500;
  color: var(--color-text);
  padding: var(--space-2);
  transition: color var(--transition-duration-fast);
}

.nav-link:hover,
.nav-link:focus {
  color: var(--color-primary);
}

/* Mobile styles */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .nav-list {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-background);
    flex-direction: column;
    padding: var(--space-4);
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--color-neutral-200);
  }

  .nav-list[hidden] {
    display: none;
  }

  .nav-link {
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--color-neutral-200);
  }

  .nav-link:last-child {
    border-bottom: none;
  }
}

/* Focus styles for accessibility */
.menu-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}