First on-hover heder self link after table of content activates table of contents instead of header

E.g.: cirosantilli.com/physics#how-to-teach-and-learn-physics

Broken ToC HTML render?

OK, understood the root cause: we moved to rendering the ToC from inside the H rendering function itself, and as a result there is a single toplevel_child_modifier which acts on that entire output.

We'll need to create something more custom to properly handle this case.