A pseudo-class sequence, Background

1 A: link; A: hover; A: active; A: visited ==> A: link; A: visited; A: hover; A: active

If a is connected to a (normal), move the mouse over B (highlighted), click "Activate", and then move the mouse up to C (gray state). The accessed a (normal)

2 Background:

Background-color | background-image | background-repeat | background-attachment | background-Position

Default Value: transparent none repeat scroll 0% 0%

3. image coordinates: right X, bottom y

4 Background-position: Position of the background image relative to the container Element

-50px,-50px: the container is fixed, the image position is shifted to 50px, and the image position is shifted to 50px.

A pseudo-class sequence, Background