I’m only mentioning this because it’s not been mentioned in any other comments but there is a Python implementation for the CEF (Chrome Embedded Framework). It let’s you write your front end in HTML/CSS and JS while letting you call back to a Python backend. You can use any existing JS framework to do your styling (offering the most flexibility) while keeping business logic in Python. It’s not exactly what you were asking for, however you mentioned in a different comment thread that tkinter looked outdated, so thought I’d mention it.

Link here https://github.com/cztomczak/cefpython

Stand and Deliver - Adam and the Ants?

Bad case of Irritable Towel Syndrome