【CSS】Intermediate2:Pseudo Classes

1.specify a state or relation to the selector

 selector:pseudo_class { property: value; }

 

2.Link

 

3.Dynamic Pseudo Classes

 apply styles when something happens to something.

active:when a link is clicked on

hover:when a cursor moves over a link

focus:when it is selected by,is ready for,keyboard input 支持度不太广泛

 

4.first-child

CSS3；last-child ,target first-of-type