清除浮动

1、给父元素加高度为浮动元素的最高高度
2、设置overflow:hidden
3、加标签clear:both
4、伪元素标签法
单伪标签
 .clearfix::after{
            content: "";
            height: 0;
            display: block;
            clear: both;
            visibility: hidden;
        }
        .clearfix{
            *zoom: 1;
        }
        
        双伪标签
        .clearfix:after,.clearfix::before{
            content: "";
            display: block;
            clear: both;
        }
        .mother{
            *zoom:1;
        }