Get your own website Result Size: 625 x 565
x
 
<!DOCTYPE html>
<html>
<title>W3.CSS</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
<body>
<div class="w3-container">
  <h2>The w3-mobile Class</h2>
  <p>The <strong>w3-mobile</strong> class adds mobile-first responsivenss to any element.</p>
  <p>It adds display:block and width:100% to an element on screens that are less than 600px wide.</p>
  <p>Resize the browser window to see the effect:</p>
  <button class="w3-button w3-black w3-mobile">Home</button>
  <button class="w3-button w3-black w3-mobile">Link 1</button>
  <button class="w3-button w3-black w3-mobile">Link 2</button>
  <button class="w3-button w3-black w3-mobile">Link 3</button>
</div>
</body>
</html>