how to highlight "active" headline in TOC sidebar widget?

Yes you can and I’ve used it in that manner at (bottom left) https://aofm.gov.au/publications/annual-reports/annual-report-2012-2013/part-2-operations-and-performance/

That was achieved using jQuery scrollspy to figure out where the user is within the content in order to highlight the current heading within the TOC. All that is required is the scrollspy javascript, then your own custom CSS to style the selected index your way. You probably want to fix the position of the index to somewhere consistent too.

thanx!

great! thanks!

ups… it’s not easy yet :/
Mike, haven’t you been thinking about TOC+ scrollspy enhancement? ??

I’m done, with Page scroll to id plugin ??