Create Bootstrap Wells
Bootstrap has a class called well
that can create a visual sense of depth for your columns.
Nest one div element with the class well within each of your col-xs-6 div
elements.
<div class="container-fluid">
<h3 class="text-primary text-center">jQuery Playground</h3>
<div class="row">
<div class="col-xs-6">
<div class="well">
</div>
</div>
<div class="col-xs-6">
<div class="well">
</div>
</div>
</div>
</div>