@sdetweil thank you for the reply. But I think I lead you down the wrong path looking for my solution…
I have MM running on a RPI it’s started by a small script running “npm start”. There it displays all of the info I am looking for. Works GREAT!!!
When I connect to it from a DIFFERENT machine is where I want to detect the screen size and adjust accordingly.
Typing the address in as xxx.xxx.xxx.xxx:8080 from my laptop display all info (same as RPI). But, if I connect and the screen is small (phone, kindle fire, 7" screen, etc) just show time, date, weather, and forecast.
I started down the path of (window.size in js) but made my config file very angry. Did not try @media in css yet.
With the COVID and the stay at home thing, have lots of time to explore…
Thank you again and be safe!