Speaking of selectors, everyone is familiar with them. It is estimated that the most commonly used ones are the id selector and the class selector. As for other selectors, I will avoid talking about them here today.
Class selector: Give the html element a loud name and mark it with class, then you can use the class selector, such as It is paragraph 1
to "p1", and then write the css style to use it directly,
For example:
p.p1{color:red;}
This paragraph will also be center-aligned.