Seems when i hide TOC, headlines reposition correctly, but body text doesn't reposition correctly. But if i click a link in the body, text repositions itself on the click. Which is of course very disruptive-- click a link and the body text moves around!? Plus, the click fails-- you don't go to the link.
Before collapsing, headline and body wrap around the TOC:
After collapse, headline moved, but body-text didn't:
After clicking link in body, body-text moved to right place:
This vid shows that body text repositions correctly only after changing window size-- which doesn't make sense.
Theory: My custom CSS creates taller margin-top for headlines. Maybe the core TOC code that forces text to reposition is confused by that?
MW v1.30
Chrome v67