<!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">
<h2>Input Sizing</h2>
<p>You can quickly size labels and form controls within a Horizontal form by adding .form-group-lg or .form-group-sm to the div class="form-group" element:</p>
<form class="form-horizontal">
<div class="form-group form-group-lg">
<label class="col-sm-2 control-label" for="lg">form-group-lg</label>
<div class="col-sm-10">
<input class="form-control" type="text" id="lg">
</div>
</div>
<div class="form-group form-group-sm">
<label class="col-sm-2 control-label" for="sm">form-group-sm</label>
<div class="col-sm-10">
<input class="form-control" type="text" id="sm">
</div>
</div>
</form>
</div>
</body>
</html>