Success! First, I resorted to using the code from your demo page, replacing your content with mine. That worked, except that your demo page had a different version of the menu, and my further adaptation didn’t work — no drop downs.
And, as expected by even me, the final mystery came down to a stupid typo: I had forgotten to put the <script> tags around your javascript. Another mystery was equally simple once I found it: a missing # before a color spec.
Suggestion: I realize your site is aimed at experienced developers, but this error was one I knew to avoid from day one of using Javascript, 20 years ago. So, as far as that goes, even I am an “expert” and even then I overlooked it. I suggest you provide your templates with the full folder tree structure already in place, including all files in the proper places, and in your examples include ALL the code to be added. Don’t assume the user will notice what is missing, however elementary. Usability 101.
Thanks. Now for the tweaking.