BFC

BFC（ block formatting context）块级格式上下文

当发生下面的任一条时，就会触发BFC

• the root element or something that contains it
• floats (elements where float is not none)
• absolutely positioned elements (elements where position is absolute or fixed)
• inline-blocks (elements with display: inline-block)
• table cells (elements with display: table-cell, which is the default for HTML table cells)
• table captions (elements with display: table-caption, which is the default for HTML table captions)
• elements where overflow has a value other than visible
• flex boxes (elements with display: flex or inline-flex)

BFC

原文：http://www.cnblogs.com/oneplace/p/5274097.html