<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<h2>Create your snippet's HTML, CSS and Javascript in the editor tabs</h2>
</div>
</div>
/*this is calles placeholder for make reusable separate css prop.. bundle which is not show in our css file*/
%abc {
color:red;
font-family: arial;
font-size: 24px;
}
.test {
@extends %abc;
}
/*if we need to add css bundle which is already defined with any predefined class or ids*/
#abc {
color:red;
font-family: arial;
font-size: 24px;
}
.test {
@extends #abc;
}