body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
  }
  
  header {
    background-color: #f1f1f1;
    padding: 20px;
  }
  
  h1 {
    margin: 0;
  }
  
  nav ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
  }
  
  nav ul li {
    display: inline;
    margin-right: 10px;
  }
  
  nav ul li a {
    text-decoration: none;
    color: #333;
    padding: 5px;
  }
  
  section {
    padding: 20px;
  }
  
  h2 {
    margin-top: 0;
  }
  
  table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
  }
  
  table th,
  table td {
    padding: 8px;
    text-align: left;
    border-bottom: 1px solid #ddd;
  }
  
  footer {
    background-color: #333;
    color: #fff;
    padding: 10px;
    text-align: center;
  }
  
  .instructor {
    display: flex;
    margin-bottom: 20px;
  }
  
  .instructor img {
    width: 150px;
    border-radius: 50%;
    margin-right: 10px;
  }
  
  .instructor-info {
    flex: 1;
  }
  
  .instructor h3 {
    margin: 0;
  }
  
  @media screen and (max-width: 600px) {
    nav ul li {
      display: block;
      margin-bottom: 10px;
    }
  }