/*公共样式*/
 /*1清除浮动*/
.clear {
    zoom: 1;
}

 .clear::after {
        content: "";
        display: block;
        clear: both;
    }
.fl {
float:left;
}
.fr {
float:right;
}
/*圆圈*/
.circle {
    width:10px;
    height:10px;
    border-radius:5px;
    background:#808080;/*要换*/
}