How to make the effect of spreading the background of the site when you click on the button?

Question

css

I want to make a button on which, if you click, the background spreads smoothly, drop the links
pls

Answer 1

I can recommend Edge Animate. You can create a simple nice animation that is unloaded in html+css+js.
Try to explain more clearly what you want to see, or show something with an example. Otherwise, it's not very clear.