/*css为clearfix，清除浮动*/
.fl {
  float: left;
}
.fr {
  float: right;
}
.clearfix::before,
.clearfix::after {
  content: "";
  height: 0;
  line-height: 0;
  display: block;
  visibility: hidden;
  clear: both;
}

.clearfix:after {
  clear: both;
} 


}