使用Bootstrap中的.alert-danger类创建一个红色警告框，指示危险操作。
您可以尝试运行以下代码来实现.alert-danger类-
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <link rel = "stylesheet" href = "https://maxcdn.bootstrapcdn.com/bootstrap/4.1.1/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/4.1.1/js/bootstrap.min.js"></script> </head> <body> <div class = "container"> <div class = "alert alert-danger"> <p>Danger!</p> <p>Add dangerous action here...</p> </div> </div> </body> </html>