body {
    font-family: Arial, sans-serif;
    margin: 20px;
  }
  
  header {
    text-align: center;
    margin-bottom: 30px;
  }
  
  h1, h2, h3 {
    margin: 0;
  }
  
  h1 {
    font-size: 28px;
  }
  
  h2 {
    font-size: 22px;
    margin-top: 10px;
  }
  
  section {
    margin-bottom: 30px;
  }
  
  h3 {
    font-size: 18px;
    margin-bottom: 10px;
  }
  
  p {
    margin: 0 0 10px;
  }