<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>
<div class="container">
<div class="col-md-12 col-sm-12 col-xs-12">
<h3>Default collapse with scaling icon</h3>
<div class="panel-group wrap" id="bs-collapse">
<div class="panel">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-parent="#bs-collapse" href="#one">
Content 1
</a>
</h4>
</div>
<div id="one" class="panel-collapse collapse">
<div class="panel-body">
Where now are the horse and the rider? Where is the horn that was blowing? Where is the helm and the hauberk, and the bright hair flowing?
</div>
</div>
</div>
<div class="panel">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-parent="#bs-collapse" href="#two">
Content 2
</a>
</h4>
</div>