Please tell me, what does this mean_html/css_WEB-ITnose

.shine {
display: block;
....
}
.button:hover .shine {left: 24px;}
.button:active .shine {opacity : 0;}

I don’t know what the pseudo-class followed by the style name here means. I would like to ask a master, thank you for clarifying

Reply to the discussion ( Solution)

.a:hover .b{
left: 24px;
}

That is, when you put the mouse on the first div, the left=24px of the div with class="b"

5 types of selectors you can learn
Tag Class ID Derived Combination

This is a derived selector. Pay attention to the hierarchical relationship. There must be spaces in the middle.

.a :hover .b{
left: 24px;
}

That is, when you put the mouse on the first div, the left=24px of the div with class="b"

5 kinds of selectors can be used Learn
tag class id derived combination

This belongs to the derived selector. Pay attention to the hierarchical relationship. There must be spaces in the middle.

Thank you