body {
    font-family: Arial, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
  }
  header {
    text-align: center;
    border-bottom: 1px solid #ccc;
    margin-bottom: 20px;
  }
  nav a {
    margin: 0 10px;
    text-decoration: none;
    color: #333;
  }
  article {
    margin-bottom: 20px;
    padding: 10px;
    border: 1px solid #eee;
  }