待解决

1. css 布局之BFC    http://www.zhangxinxu.com/wordpress/2015/02/css-deep-understand-flow-bfc-column-two-auto-layout/

2. css  布局之 display：table 与display：table-cell  http://www.zhangxinxu.com/wordpress/2010/10/%E6%88%91%E6%89%80%E7%9F%A5%E9%81%93%E7%9A%84%E5%87%A0%E7%A7%8Ddisplaytable-cell%E7%9A%84%E5%BA%94%E7%94%A8/

3.值的两种类型与值的传递  https://www.zhihu.com/question/27114726