Nit: please don’t push to my browser history every time I expand one of the sections… I had to press my browser’s back button a dozen or so times to get back out of your site.
Thanks. I'll look into that. It was recommended exactly for backtracking but I get that if you want to leave it's a whole lot of backpaddling :-)
You can also hold down the back button to get a menu of previous pages in order to skip multiple back button presses. (I still agree with your point and you might already know that. Maybe it helps someone.)