accordion.html

<div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
	<div class="panel panel-default">
		<div class="panel-heading" role="tab" id="headingOne">
			<h4 class="panel-title">
				<a role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne"> Title 1</a>
			</h4>
		</div>
		<div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne">
			<div class="panel-body">Content 1</div>
		</div>
	</div>
	<div class="panel panel-default">
		<div class="panel-heading" role="tab" id="headingTwo">
			<h4 class="panel-title">
				<a role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseTwo" aria-expanded="true" aria-controls="collapseOne"> Title 2</a>
			</h4>
		</div>
		<div id="collapseTwo" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingTwo">
			<div class="panel-body">
				<div class="panel-body">Content 2</div>
			</div>
		</div>
	</div>
	<div class="panel panel-default">
		<div class="panel-heading" role="tab" id="headingThree">
			<h4 class="panel-title">
				<a role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseThree" aria-expanded="true" aria-controls="collapseOne"> Title 3</a>
			</h4>
		</div>
		<div id="collapseThree" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingThree">
			<div class="panel-body">Content 3</div>
		</div>
	</div>
</div>