(nitpick) White box at github.com when signed into a new account

[gregk-git]

Describe the bug:
When you make a new account, and sign in, and go to github.com, there's a large white box that is clearly visible. I suspect most users of your theme will never ever see it, due to them most likely making a github account long before downloading the style, so this is really nitpicking.

Expected behavior:
The box would be themed.

Where did this happen:
https://github.com/

Steps to reproduce:

1. Create a new account
2. Sign in
3. Go to https://github.com/

Screenshots:
Chrome:
Firefox:

Desktop (please complete the following information):

• OS: Windows 10 OS Version 1909 (Build 18363.720)
  Browser and Versions tested:

Browser	Version
Google Chrome	81.0.4044.92 (Official Build) beta (64-bit) (cohort: Beta)
Firefox	76.0b3 (64-bit) beta

Additional add-ons installed:
Note: Dark Reader is not being used on GitHub
Chrome:
Firefox: