要使输入组较小，请使用input-group-sm。
您可以尝试运行以下代码以在Bootstrap中实现input-group-sm类：
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet"> <script src = "/scripts/jquery.min.js"></script> <script src = "/bootstrap/js/bootstrap.min.js"></script> </head> <body> <div style = "padding: 100px 100px 10px; background: blue;"> <form class = "bs-example bs-example-form" role = "form"> <div class = "input-group input-group-sm"> <span class = "input-group-addon">$</span> <input type = "text" class = "form-control"> </div> </form> </div> </body> </html>