Tente você mesmo - W3.CSS nav_font

<!DOCTYPE html>
<html>
<title>W3.CSS</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="/lib/w3.css">
<link rel="stylesheet" href="../../cdnjs.cloudflare.com/ajax/libs/font-awesome/4.4.0/css/font-awesome.min.css">
<body class="w3-container">

<p>w3-small:</p>
<div class="w3-topnav w3-small w3-black">
  <a href="#"><i class="fa fa-home w3-small"></i></a>
  <a href="#">W3Schools</a>
  <a href="#">Link 1</a>
  <a href="#">Link 2</a>
  <a href="#">Link 3</a>
</div>
<p>w3-medium:</p>
<div class="w3-topnav w3-orange">
  <a href="#"><i class="fa fa-home w3-large"></i></a>
  <a href="#">W3Schools</a>
  <a href="#">Link 1</a>
  <a href="#">Link 2</a>
  <a href="#">Link 3</a>
</div>
<p>w3-large:</p>
<div class="w3-topnav w3-large w3-red">
  <a href="#"><i class="fa fa-home w3-large"></i></a>
  <a href="#">W3Schools</a>
  <a href="#">Link 1</a>
  <a href="#">Link 2</a>
  <a href="#">Link 3</a>
</div>
<p>w3-xlarge:</p>
<div class="w3-topnav w3-xlarge w3-blue">
  <a href="#"><i class="fa fa-home w3-xlarge"></i></a>
  <a href="#">W3Schools</a>
  <a href="#">Link 1</a>
  <a href="#">Link 2</a>
  <a href="#">Link 3</a>
</div>
<p>w3-xxlarge:</p>
<div class="w3-topnav w3-xxlarge w3-green">
  <a href="#"><i class="fa fa-home w3-xxlarge"></i></a>
  <a href="#">W3Schools</a>
</div>
<p>w3-xxxlarge:</p>
<div class="w3-topnav w3-xxxlarge w3-teal">
  <a href="#"><i class="fa fa-home w3-xxxlarge"></i></a>
  <a href="#">W3Schools</a>
</div>

</body>
</html>