What to do with the hover pseudo-class?

Question

css

I have one block. Inside this block there are 4 more blocks of the same width and height. How to make it right so that when you hover over each of the 4 blocks, another block appears from the bottom and at the same time the 4 upper blocks remain in their places, and the new block appears directly below them.

Answer 1

Adding style to an element on hover