Dunno if this is a bug or if it was designed this way, but since launch I've been seeing the docs site on mobile basically work like this when you click to open the sidebar (see clip)
it would be 1 million times more usable+discoverable on mobile if this opened a table of contents nav in a sidebar
as an example, Openclaw's docs sidebar actually handles sprawl quite well - it uses a dropdown for the main headers then loads a list of subheaders/pages, if you want a clean approach I'd start with that