We should update `sphinx-proof` to: - reduce padding around `assumption` directives (as currently excessive) (example: https://python.quantecon.org/von_neumann_model.html#model-ingredients-and-assumptions) <img width="621" height="465" alt="Image" src="https://github.com/user-attachments/assets/ae13275e-5b08-47da-a6f7-c876438aafbf" /> - [ ] enable a `minimal` styling mode that reduces the visual impact (no `bgcolor`)