JSFiddle - React, Tailwind, and code Playground
HTML
<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/4.1.3/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>
</head>
<div id="box1">
<span class="padding">padding in span</span>
<span class="padding">padding in span</span>
</div>
<hr />
<div id="box2">
<span class="margin">margin outside of span</span>
<span class="margin">margin outside of span</span>
</div>
<div class="p-3 mb-2 bg-danger text-white">.bg-danger</div>
<div>
<lablel class="bg-danger">should be in bg-danger</lablel>
</div>
<div>
<input type="text" name="lname" class="bg-danger" >
</div>
CSS
div{
border:1px solid #000;
}
.padding{
padding:10px;
border:1px solid red;
}
.margin{
margin:10px;
border:1px solid red;
}