body {
    font-family: 'Open Sans', sans-serif;
    color: #333;
    background-color: #fff;
  }
  
  header {
    background-color: #333;
    color: #fff;
    padding: 20px;
    text-align: center;
  }
  
  nav {
    background-color: #ccc;
    padding: 10px;
    text-align: center;
  }
  
  nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
  }
  
  nav li {
    display: inline-block;
    margin-right: 10px;
  }
  
  nav a {
    color: #333;
    text-decoration: none;
    font-weight: bold;
  }
  
  main {
    padding: 20px;
    text-align: center;
  }
  
  .button {
    display: inline-block;
    background-color: #333;
    color: #fff;
    padding: 10px 20px;
    text-decoration: none;
    font-weight: bold;
    transition: 0.3s all;
  }
  
  .button:hover {
    background-color: #fff;