<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<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>
</head>
<body>
<div class="container">
<h1>Input Group Size</h1>
<p>The .input-group class is a container to enhance an input by adding an icon, text or a button in front or behind it as a "help text".</p>
<p>Use the .input-group-lg if you want a large input group:</p>
<form>
<div class="input-group input-group-lg">
<input type="text" class="form-control" placeholder="Search">
<div class="input-group-btn">
<button class="btn btn-default" type="submit"><i class="glyphicon glyphicon-search"></i></button>
</div>
</div>
</form>
<br>
<p>Use the .input-group-sm if you want a small input group:</p>
<form>
<div class="input-group input-group-sm">
<input type="text" class="form-control" placeholder="Search">
<div class="input-group-btn">
<button class="btn btn-default" type="submit"><i class="glyphicon glyphicon-search"></i></button>
</div>
</div>
</form>
</div>
</body>
</html>