CSS 生成内容

CSS Generated Content 是CSS其中一个模块，定义了如何给一个元素添加内容

参考

规范	状态	注释
CSS Generated Content Module Level 3	Working Draft
CSS Level 2 (Revision 1)	Recommendation	Initial definition

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 8	Opera Full support 4	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support Yes	Edge Mobile Full support Yes	Firefox Android Full support 4	Opera Android Full support 9.5	Safari iOS Full support 1	Samsung Internet Android Full support Yes
Element replacement	Chrome Full support Yes	Edge ?	Firefox Full support 63	IE ?	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android ?	Edge Mobile ?	Firefox Android Full support 63	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
`url()`	Chrome Full support 1	Edge ?	Firefox Full support 1	IE Full support 8	Opera Full support 7	Safari Full support 1	WebView Android ?	Chrome Android ?	Edge Mobile ?	Firefox Android ?	Opera Android ?	Safari iOS ?	Samsung Internet Android ?