JSFiddle - React, Tailwind, and code Playground
HTML
<script src="https://code.jquery.com/jquery-3.4.1.slim.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.css">
<head>
<!-- boilerplate to get the bootstrap things -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.0/css/bootstrap.min.css">
</head>
<body>
<!--
for proper bootstrap magic
rows go in a container
-->
<div class="container">
<!-- columns go in a row -->
<div class="row">
<!-- from xs upwards, make columns full-width -->
<!-- then from lg upwards, make columns partial-width -->
<div class="col-xs-12 col-md-8" style="background-color:blue">
1 of 2
</div>
<div class="col-xs-12 col-md-4" style="background-color:pink">
2 of 2
</div>
</div>
</div>
<!-- boilerplate to get the bootstrap things -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.0/js/bootstrap.min.js"></script>
</body>