<style>
  * {
    box-sizing: border-box;
  }
 
  body {
    font-family: Arial, sans-serif;
    margin: 0;
  }
 
  header, footer {
    background-color: #333;
    color: white;
    padding: 10px;
    text-align: center;
  }
 
  nav {
    background-color: #f4f4f4;
    padding: 10px;
    width: 20%;
    float: left;
    height: 300px;
  }
 
  main {
    float: left;
    width: 60%;
    padding: 10px;
    height: 300px;
  }
 
  aside {
    float: left;
    width: 20%;
    background-color: #f9f9f9;
    padding: 10px;
    height: 300px;
  }
 
  footer {
    clear: both;
  }
</style>
 
<header>
  <h1>Website Layout</h1>
</header>
 
<nav>
  <p>Navigation</p>
</nav>
 
<main>
  <p>Main Content</p>
</main>
 
<aside>
  <p>Sidebar</p>
</aside>
 
<footer>
  <p>Footer</p>
</footer>