<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container mt-3">
<h2>Display Utilities</h2>
<p>To create a block element, add the d-block class. Use any of the d-*-block classes to control WHEN the element should be a block element on a specific screen width.</p>
<p>Resize the browser window to see the effect.</p>
<span class="d-block bg-success">d-block</span>
<span class="d-sm-block bg-success">d-sm-block</span>
<span class="d-md-block bg-success">d-md-block</span>
<span class="d-lg-block bg-success">d-lg-block</span>
<span class="d-xl-block bg-success">d-xl-block</span>
</div>
</body>
</html>