AJAX Drop Down About box

This is a good place to start.

https://www.onlinetools.org/tools/domcollapse/

Found it!
https://asymptomatic.net/2006/04/13/2311/building-a-shelf-in-wordpress/

Which is exactly what Owen does on his site!!

Here’s a link that shows how to do it with unobtrusive javascript. Keeps things nice and separate.

https://www.exit404.com/2005/57/unobtrusive-persistant-scriptaculous-effects

Good link, thanks for sharing. I’ll take a look at this later.