For theme, you have several good options. The clean, light-weight Furo theme is shown above. Many scientific packages choose the sphinx-py-data theme, which is also a good choice (no dark mode, though).
(gets the name of pydata-sphinx-theme wrong, and is also wrong about dark mode)
Ideally though I think the examples should use PST instead of Furo, since PST uptake is pretty broad among the core packages now
https://learn.scientific-python.org/development/guides/docs/
This passage in particular needs some help:
(gets the name of pydata-sphinx-theme wrong, and is also wrong about dark mode)
Ideally though I think the examples should use PST instead of Furo, since PST uptake is pretty broad among the core packages now