Content character encoding in css3

content has 5 attributes

content:""; // It is empty

content:attr(title); // You can get the tag attribute value or you can get the custom attribute value. For example,

css is div:after{content ; It's "counter(title)", I'm afraid of "counter(gaga);} The result is "I am gaga2, I'm afraid of gaga1";

content: "21e0"; //Get the character set icon slash of the following picture Escape, but there are some differences between some icons directly in the browser

content:url(123.gif); //Use the specified absolute or relative address to insert an external resource (image, audio, video or other supported by the browser) any resources)