Dear Cameron:
It seems you CAN teach an old dog new tricks!
Well, maybe...
I understood the concept that the style sheet drives the element, but it never occurred to me to check the margin settings! Then, my next thought was, how in the nine circles of Hades did he find that so damned fast?! I couldn't admit I couldn't find it, so I stumbled around, until I tripped over it, picked myself up, dusted myself off, and exclaimed, "Aha! A clue!"
Through much trial and error, I reduced the margin setting from 20% to 13%, and it worked -- in spite of my best efforts!
Cameron, I really appreciate the help! I'm going to have to spend more time on the CSS, since there are other details I want to tweak.
BC_Programmer: Greetings! Not up on the hardware and OS stuff, like once I was, so I drop in every so often, but really haven't contributed.
You are quite right about the CSS: changing the margin setting for the accordion element has it centered on one page, but has caused an accordion on another page to become off-center. It's good for now. The difference on the other page is not that important.
You'll probably see me post more questions in Web Design...also in Linux. I'm probably going to bail on Windows 10 in favor of OpenSUSE. (Stop laughing, Cameron.
)