边框不能与bootstrap 4一起使用

Jee*_*ese 4 html css twitter-bootstrap bootstrap-4

我是bootstrap的新手,我不确定我是否做错了什么,但我无法让class ="border border-danger"工作.休息所有其他样式工作得很好.这是我的代码.

    <html lang="en">
    <head>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">
        <script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>
    </head>
    <body class="container">
        <div class=" text-center m-2 text-primary">
            
            <h2 class="h4"> SAMPLE DATA FOR RENDERING </h2>    
            <blockquote class="blockquote bg-warning text-white p-2 border" >Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 
                Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. 
                Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. 
                Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. - Lorem Ipsum</blockquote>

            
        </div>
       
        <div class=" border border-danger  border">
            <p class="text-uppercase w-75" > Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.  </p><br>
            <button class="btn btn-primary btn-block"> Submit </button>
        </div>
        
    </body>
</html>
Run Code Online (Sandbox Code Playgroud)

此代码段的输出如下所示. 在此输入图像描述

Kal*_*kar 5

我认为你使用的是bootstrap4 alpha版本.在border-danger我看来这个版本不存在.使用bootstrap4 beta版.