1. What is a pseudo-elements, what is the pseudo-class?
A: Simply look at the situation from realization,
:: the before, the After ---- :: pseudo-elements
: first-child,: hover ---- pseudo-class
if not clear, please refer to the following article, https: // www .cnblogs.com / ammyben / p / 8012747.html
2. How to use pseudo-elements before and after it?
The basic use of 2.1 before and after pseudo elements
<! DOCTYPE HTML > < HTML lang = "EN" > < head > < Meta charset = "UTF-. 8" > < title > Basic use before and after pseudo-elements </ title > < style > P: before { Content : "H" / * : before and: after skills will bring the importance of the full five stars * / } P: after { Content : "D" / * : before and:after will bring skills, the importance of full 5 Stars * / } </ style> </head> <body> <p>ello Worl</p> </body> </html>