I'm sad to see this didn't come with a responsive design for the main site. You get horizontal scrollbars everywhere if your window is thinner than ~1000 pixels, making it impossible to have code + GitHub side by side on a laptop without some serious annoyance. The repo redesign made it worse, as now all the in-project links (issues, pulls, wiki...) are offscreen.
I'd happily work around this by using the mobile view from my desktop browser (as you can do on Wikipedia and many news sites), but GitHub doesn't seem to have made that possible, either.
If any GitHubbers are reading, please make the design (at least a little bit) responsive!