<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.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 class="row">
<header class="col-lg-6">Je suis le boss</header>
</div>
<div class="row">
<form class="col-sm-10 col-md-10 col-lg-10">
<div class="input-group">
<span class="input-group-addon">nom</span>
<input type="text"/>
</div>
</form>
</div>
</div>