Script to change OO document style

I’ve just spent an hour on with no luck. I’d like a script that can apply a new template style and also change the zoom level of a document (or I could just have this as part of the template I suppose?)

The use case is that I work in dark mode with small text, but I walk into the classroom and need it to be bigger and in light mode for the sake of presenting to my class. Once I work out the script I would plan to automate it in Shortcuts according to my weekly schedule.

Any ideas out there how this could be done?