方法1.#box{clear:both} /*#box为浮动元素的下一个兄弟元素*/
方法2.#box{display:block;zoom:1;overflow:hidden;}/*#box为浮动元素的父元素*/
方法3.#box{zoom:1;};#box:after{display:block;clear:both;visibility:hidden;height:0;content:‘‘;} /*#box为浮动元素的父元素*/
原文：https://www.cnblogs.com/xiaominss/p/10826212.html