How do I make a box of text that can be expanded / collapsed by the user?
I am trying a new way of presenting math, where proofs / weird cases / asides can be automatically minimized to ease general understanding, but available and expandable for the sake of rigor. So I want a text-box (there may be an official word for this that I do not know) with a title and a close/open button, so that people may make it visible or invisible as desired.
The blog I need help with is examplesinmodeltheory.wordpress.com.