MacOS Chrome? The code blocks look fine to me in linux {firefox, chromium, brave}. I think they're all using Qt.

Now, it looks fine to me too. I tested it in Chrome,Firefox, Safari on macOS and on Safari on an iPad yesterday when I wrote my comment and in all cases there were black lines all over the the place. The author corrected the problem, see https://news.ycombinator.com/item?id=48855382

Looks fine to me in Chrome on Mac.