I would love HN to provide an easy way to see where the reply thread to this first comment ends. Some js might enable that. Basic html/css - I think no.
It's that [-] button next to the username above each comment. It collapses all the cascading comments. It is enabled via JS. If you disable JS, then it disappears.
Thanks, I didn't see it
I suspect you could hack a similar collapsing thread UI together with styled radio buttons and no JS, if you really wanted to prove a point.