body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
  }
  
  nav {
    background: #333;
    color: #fff;
    padding: 1rem;
  }
  
  nav ul {
    list-style: none;
    padding: 0;
  }
  
  nav ul li {
    display: inline;
    margin-right: 1rem;
  }
  
  nav ul li a {
    color: #fff;
    text-decoration: none;
  }
  
  .container {
    padding: 2rem;
    background: #fff;
    margin: 2rem auto;
    max-width: 800px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  }
  
  h1 {
    color: #333;
  }
  
  .quiz ul {
    list-style: none;
    padding: 0;
  }
  
  .quiz ul li {
    margin: 0.5rem 0;
  }
  
  .quiz ul li button {
    padding: 0.5rem 1rem;
    border: none;
    background: #007bff;
    color: #fff;
    cursor: pointer;
  }
  
  .quiz ul li button:hover {
    background: #0056b3;
  }