<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="https://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script>
<script src="https://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<style>
.btn:after { font-family: "Glyphicons Halflings";
content: "\e114";
float: right;
margin-left: 15px;
}
.btn.collapsed:after { content: "\e080";
}
</style>
</head>
<body>
<div class="container">
<h2>Simple Collapsible</h2>
<button type="button" class="btn btn-lg btn-info collapsed" data-toggle="collapse" data-target="#demo">Simple collapsible</button>
<div id="demo" class="collapse">
Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
</div>
</div>
</body>
</html>