.header {
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-dark) 100%
  );
  color: white;
  padding: var(--spacing-md) 0;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 2.4rem;
  font-weight: 700;
  text-decoration: none;
  color: white;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo::before {
  content: '🚂';
  font-size: 3rem;
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.nav-links a {
  color: white;
  text-decoration: none;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: background-color 0.175s ease;
  font-weight: 500;
}

.nav-links a:hover,
.nav-links a.active {
  background-color: rgba(255, 255, 255, 0.1);
}