Pure CSS/HTML spoiler boxes!
They're not perfect - the main issue is that they will close if you click anywhere outside the box, and I can't do anything about it. (Test with the boxes below)
They can be styled fairly easily and the close not-really-button can be removed if you don't want it!

Copy and paste this into your CSS box (just once will do), and edit the top section as you like to style the boxes' appearance!
CSS here

Copy and paste this into the Profile box (in HTML mode - turn off WYSIWYG) to make a box.
HTML here
Yeah that's a lot of nested divs I know

Demo: