This article was not translated to English, It will be done in few days. It would be nice if you can help me to translate.
一个用户打印时的css属性，一般情况下设置背景色的时候打印时会被忽略，如果想打印的时候也将背景色打印出来就可以使用这个属性，用法：
This article was not translated to English, It will be done in few days. It would be nice if you can help me to translate.
CSS变得更像一个编程语言了，除了此次的css variables，还有很多提案，感兴趣可以去查一下。
css variables让我们可以在CSS中使用变量了，使用和SCSS语法中的$my-color: red;类似
This article was not translated to English, It will be done in few days. It would be nice if you can help me to translate.
@supports是CSS3新引入的规则之一，主要用于检测当前浏览器是否支持某个CSS属性并加载具体样式.
