要在指示积极行动的按钮上设置轮廓，您需要使用Bootstrap中的btn-outline-success类。
设置方法如下：
<button type="button" class="btn btn-outline-success"> More (Green Outline) </button>
您可以尝试运行以下代码以实现btn-outline-success类-
<!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://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script> </head> <body> <h2>Python</h2> <p>The following are the Python Technologies :</p> <ul class = "list-group"> <li class = "list-group-item">Jython</li> <li class = "list-group-item">WxPython</li> </ul> <p>For more, click below:</p> <button type="button" class="btn btn-outline-success">More (Green Outline)</button> </body> </html>