Quill: Can't use CSS :focus selector on editor

[JLShrago]

I want to apply my own styling to the editor on focus in my own CSS but the pseudo class selector doesn't work.
:active and :hover both work.

Steps for Reproduction

Add pseudo selector to loaded CSS with some styling.

Expected behavior:

Should add styling when the editor is focused.

Actual behavior:

There is no change in the styling.

Platforms:

Latest Chrome and FF

Version:

1.2.0

[benbro]

Working for me.
In this CodePen :hover paint the background in red.

[benbro]

This CodePen use the :focus selector.