Hi, I'm have no experiences regarding design or CSS or the like, but I have created some sort of a proposal for this, using an adapted alabaster theme.
See <https://people.debian.org/~holgerw/sphinx-theme-for-debian/alabaster/> The used conf.py can also be found there for reference. While it looks good IMO on laptos, PC etc., it does not on a small screen like on smartphones, because the sidebar gets unvisible. Maybe someone can help with that? Holger -- Sent from /e/ OS on Fairphone3