responsive

if you were building separate urls, its the same work.

use variables and calc at the beginning…see main.css

What sort of system resources would two instances consume? I’m running on a Pi 4b, that’s also being used as a local web server and weather station. So critical functions - would two instances of MM cause high cpu/memory usage?

I think the time it would take me to learn enough CSS to build responsive pages for my 4/5 devices would exceed my current free time :-D

Cheers again!

but you could run multiple instance w different configs from the same files. using the
environment variable

MM_CONFIG_FILE=/user/pi/MagicMirror/config/config.js
you can also use environment variable for port
MM_PORT=8080

note that css can detect size, orientation and vendor

if width is less than height, then in portrait mode

so you could have a customized custom.css that would do all that