Plus and minus symbols for accordion menu

I have created an accordion style menu following this excellent tutorial from @waldo It works perfectly but I’d like to tweak it so the down arrow that is currently used is replaced by a plus sign that changes to a minus once opened rather like at

Would certainly appreciate any advice!

Here is my public share link: LINK
(how to access public share link)

I use 2 small black divs to make a minus and plus symbol, and I target them with the global interaction.


hey! do you still have this example?