Ask HN: Web framework for custom character sheets?

I'm making a TTRPG, and the skill system involves lots of synergy hierarchies, and interactions. It involves rules that are easy to express in code, but just complicated enough that Excel is very cumbersome. Add to that Excel doesn't have a "roll this check" functionality.

Is there a JS lib or Django-like stack for building something that would serve as a character sheet builder?

I'd like to avoid Roll20 based on their junk mapping utils.