I have written a fairly complex application (Youtube Transcript Extraction) in Python3, which comes in at 700 SLOC, and it currently runs directly from my terminal on an Ubuntu Desktop. However I plan to make a Graphical User Interface (GUI) for it, so that I can pretend to be a grown-up, and also package & distribute the application to those who prefer to use a GUI. Usually I would smash something up with a Flask (Python3) app, with a minimal set of user controls, zero styling so rendered Foreground=Black, Background=White, minimal labelling etc. Functional but fugly 😁 Since I am here I thought I should ask, how would I approach the design, scoping and execution of a GUI with regard to contemporary but neutral styling, UX and performance considerations? What technical stack should I use for the GUI? How do I choose the styling etc if I want this brand-agnostic? Happy to read existing documentation or video sources, but to be honest, I have zero clue.