<html><head> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://www.w3schools.cn/lib/bootstrap/3.3.5/css/bootstrap.min.css"></head><body><div class="container"> <h2>按钮</h2> <p>.btn-sm 类制作小按钮：</p> <button type="button" class="btn btn-sm">小默认按钮</button> <button type="button" class="btn btn-info btn-sm">小信息按钮</button> </div></body></html>