Sphinx is two things: a structured markup language and a processing/presentation tool. What's noticeable in this case, is the presentation. IMO, choosing a markup language for the presentations its standard tool offers, may be an error. As an example, DITA is an OASIS standard (better standard to my opinion than Sphinx) and can be used to produce presentation similar to the good one at the link above.
I personally enjoy Sphinx's generated presentations, but less its markup language and processing model.
This comment was just to avoid a confusion, and was not to say Sphinx is not good (even if I personally believe DITA is a better standard than Sphinx, there are people who have the opposite opinion).