代码示例：（标识：bs_button_group_size）
<!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 href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/js/bootstrap.min.js"></script>
</head>
<body>
<div class="p-4">
<h2>按钮组大小</h2>
<p>添加类 .btn-group-*，可调整按钮组中所有按钮的大小。</p>
<h3>大型按钮：</h3>
<div class="btn-group btn-group-lg">
<button type="button" class="btn btn-primary">华为</button>
<button type="button" class="btn btn-primary">大疆</button>
<button type="button" class="btn btn-primary">小米</button>
</div>
<hr>
<h3>默认按钮：</h3>
<div class="btn-group">
<button type="button" class="btn btn-primary">华为</button>
<button type="button" class="btn btn-primary">大疆</button>
<button type="button" class="btn btn-primary">小米</button>
</div>
<hr>
<h3>小型按钮：</h3>
<div class="btn-group btn-group-sm">
<button type="button" class="btn btn-primary">华为</button>
<button type="button" class="btn btn-primary">大疆</button>
<button type="button" class="btn btn-primary">小米</button>
</div>
</div>
</body>
</html>
