sphinx-design is already ready to use and acts as an improved version of sphinx-panels which will eventually replace.

IIRC, we are using sphinx-panels for the card views in the community and about us pages, and for the tabs in example gallery and label guide. So these are the pages that need updating as well as checking that I have not forgotten to mention any page.

reference: https://sphinx-design.readthedocs.io/en/sbt-theme/