清除浮动造成的塌陷

转载于：http://less.bootcss.com/features/#features-overview-feature

学习less过程中遇到的清除浮动造成的塌陷的css写法
（比较全且考虑了ie）
less

.clearfix {
  display: block;
  zoom: 1;

  &:after {
    content: " ";
    display: block;
    font-size: 0;
    height: 0;
    clear: both;
    visibility: hidden;
  }
}

css

.clearfix {
  display: block;
  zoom: 1;
}
.clearfix:after {
  content: " ";
  display: block;
  font-size: 0;
  height: 0;
  clear: both;
  visibility: hidden;
}