How CSS implements a paragraph at the beginning indent two kanji

How CSS implements a paragraph at the beginning indent two kanji:

When writing an article, it is generally necessary to start a new paragraph with a blank space of two characters. Here's how you can use CSS to achieve this kind of effect.

The code is as follows:

<! DOCTYPE html> 
 
  This unit, because its size is relative to the font size of the object, for example, if the font size of the object is 12px, then 1em=12px, so no matter how large the object font is, can maintain 2 characters indentation. 
 
  http://www.51texiao.cn/div_ cssjiaocheng/2015/0519/1907.html   
 
The most original address is: http://www.softwhy.com/forum.php?mod=viewthread&tid=4713
 

How CSS implements a paragraph at the beginning indent two kanji