要将灰色背景色添加到活动链接，请使用Bootstrap中的.active类。
您可以尝试运行以下代码来实现.active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> <nav class = "navbar navbar-default"> <div class = "container-fluid"> <div class = "navbar-header"> <a class = "navbar-brand" href = "#">Website</a> </div> <ul class = "nav navbar-nav"> <li class = "active"><a href = "#">Home</a></li> <li><a href = "#">Tutorials</a></li> <li><a href = "#">Quiz</a></li> </ul> </div> </nav> <div class = "container"> <h3>Demo</h3> <p>This is demo text.</p> </div> </body> </html>