Can Latex be used to type a math article containing invisible proofs, each of which becomes visible under the relevant theorem when a button or link is clicked?
You can use
Your main document will look something like this:
Here's an image of the output produced by the main document:
And some images of what you get when your mouse hovers over the text "Click here to see the proof.":
This can be achieved with Optical Content Groups (OCG). There are some packages that support OCG. A CTAN search revealed the following packages:
The package requires
The text "My proof." should be invisible first. After pressing "Toggle proof" the proof should appear.
However, OCGs are not supported by all PDF viewers.