How to make a hover effect like in Windows 10?

Question

css

How to make such an effect when hovering over blocks like in Windows 10 joxi.ru/12Mp6ezFMvPKxm?

Answer 1

1. A set of elements with borders (blocks-flex-grids to taste).
2. Absolutely positioned top element at 200vh/200vw with a background in the form of a radial gradient from transparent to the background color of body or whatever is underneath.
3. In the above elements, we set the z-index for the texts and they fall on top of the gradient.
4. Attach a handler to the mousemove event that changes the coordinates of the gradient.
We get something like this:
codepen
PS: And in the future, insert pictures here, and not on the left hosting.

Answer 2

Making a grid background. You make a big picture with a hole in the center. You position this image on top of the grid so that the center of the hole is where the cursor is.