[apankrat]

The sidebar is an index of several additional option pages, shown to the right of it. The first one is "Common" and it is shown by default.

This design didn't actually make it into the production release, it was replaced with https://bvckup2.com/wip/r82-rabbit-hole-x.gif.

Pi is a reference to a (really corny) "hacker" movie from the 90s called The Net. Same thing as the Pi at the bottom right of every page on Reddit.

[nvrspyx]

The replacement makes much more sense to me. Thank you for the explanation.

> Same thing as the Pi at the bottom right of every page on Reddit

I'm always on Reddit and never noticed the Pi. Thanks for the trivia as well!