body {
    font-family: Arial, sans-serif;
    margin: 20px;
    padding: 0;
  }
  nav a {
    text-decoration: none;
    margin-right: 15px;
    color: blue;
  }
  nav a:hover {
    text-decoration: underline;
  }
  button {
    display: block;
    margin-top: 20px;
  }