Box Model

content content-box
padding padding-box
border border-box
margin margin-box

    ![](https://cdn.nlark.com/yuque/0/2019/png/129208/1561347828784-803d3ee8-3510-49e6-a5ea-ef7fe4d8029c.png)

W3C标准盒模型：

box-sizing: content-box | border-box | inherit， 默认为content-box
W3C标准盒模型是content-box
怪异模式，IE盒模型是border-box

参考

Introduction to the CSS basic box model
The CSS Box Model