body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
  }
  
  header {
    background: #333;
    color: #fff;
    padding: 1rem 0;
  }
  
  header nav ul {
    display: flex;
    list-style: none;
    justify-content: center;
    margin: 0;
    padding: 0;
  }
  
  header nav ul li {
    margin: 0 1rem;
  }
  
  header nav ul li a {
    color: #fff;
    text-decoration: none;
  }
  
  main {
    padding: 2rem;
  }
  
  footer {
    text-align: center;
    padding: 1rem 0;
    background: #f4f4f4;
  }