小练习（2）

*{
                margin: 0px;
                padding: 0px;
            }
            ul{
                list-style: none;
                }
            li{
                 100px;
                height: 49px;
                float: left;
                border-top: 1px solid transparent;
                
                }
                #cc{
                     500px;
                    height: 50px;
                    border: 1px solid gray;
                    text-align: center;/*水平居中*/
                    line-height: 50px;/*垂直居中*/
                }
                li:hover{
                    
                    background-color: gray;
                    color: white;
                    border-top: 1px solid red;
                    cursor: pointer;
                    
                }