Improve responsive design
Currently, things don't look too good on mobile.
I doubt you'd like to use a framework, but if you do I could set up something with Bootstrap's grid only.
Our front page is based on a Material Design Lite example, and it looks pretty alright for me on mobile.
We can tweak initial-scale if the font is too small on a lot of devices.
Doesn't look too good here.
The code should be in pre, the button clearly overflows, the GitHub ribbon is wrong and .content clearly overflows too.
Doesn't look too good here.
Hmm, that looks significantly worse than any device I've tested, or can emulate in DevTools. What is that screenshot from?
That's just with using S7 in Firefox emulator. But you will get the same results if you visit the site via a mobile device.