RocSchool|TryEditor(代码在线运行工具)

<!DOCTYPE html>    
<html>    
    
<head>    
    <title>   
        button background Color   
    </title>   
        
    <style>   
    body{  
       text-align: center;  
    }  
        button {  
           color:lightgoldenrodyellow;  
            font-size: 30px;   
        }   
        .b1{  
           background-color: lightblue;  
           border:5px red double;       
           border-radius: 25px;  
           color:black;  
           box-shadow : 0 8px 16px 0 black,   
                    0 6px 20px  0 rgba(0, 0, 0, 0.19);   
        }  
        .b2{  
         background-color: lightblue;  
           border:5px red dotted;       
           color:black;  
           border-radius: 25px;  
        }  
        .b2:hover{  
           box-shadow : 0 8px 16px 0 black,   
                    0 6px 20px  0 rgba(0, 0, 0, 0.19);   
        }  
        </style>   
</head>   
    
<body>    
    <button class="b1">Shadow on button</button>    
    <button class="b2">Box-shadow on hover</button>  
</body>    
</html>