Thanks for replying everyone. I’m familiar enough with CSS to know the standard tricks and such. Sorry if that doesn’t sound too nice, I don’t mean it that way.
I was really just hoping Discourse had some setting somewhere to force its own css to ignore custom containers with specific ids or classes. It would really save a lot of time.
Anyway, think I got most of it; and I’ll just have to keep an eye on any major CSS changes Discourse add along the way and compensate.