.header {
  background: var(--primary);
  color: white;
  padding: 2rem;
  text-align: center;
}

.nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  list-style: none;
  background: white;
  padding: 1rem;
  justify-content: center;
}

.nav a {
  text-decoration: none;
  color: var(--primary);
  font-weight: 600;
}

.container {
  max-width: 1100px;
  margin: auto;
  padding: 2rem;
}

.modules-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}