W3Schools Tryit Editor

<!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-sidebar w3-bar-block w3-card w3-animate-left" style="display:none" id="mySidebar">
  <button class="w3-bar-item w3-button w3-large"
  onclick="w3_close()">Close &times;</button>
  <a class="w3-bar-item w3-button" href="#">Link 1</a>
  <a class="w3-bar-item w3-button" href="#">Link 2</a>
  <a class="w3-bar-item w3-button" href="#">Link 3</a>
</div>

<div class="w3-container">
<p>In this example, the sidebar is hidden (style="display:none")</p>
<p>It is shown when you click on the menu icon in the top left corner.</p>
<p>When it is opened, it shifts the page content to the right.</p>
<p>We use JavaScript to add a 25% left margin to the div element with id="main" when this happens. The value "25%" matches the width of the sidebar.</p>
</div>

</div>

</body>
</html>