*{
    margin: 0;
    padding: 0;
}
ul li{
    list-style: none;
}
body{
    background: #f3f4f7;
}
/*清除浮动*/
.clear{
    content: "";
    display: table;
    clear: both;
}
.clearfix:after{
    content: "";
    display: block;
    clear: both;     //清除左右两边浮动
    visibility: hidden;
}
.clearfix{
    *zoom: 1;
}