Custom Properties not applied on pseudo classes

[tomi-msft]

When an element's pseudo class is styled using css variables, the styling fails to render in ie11 if the element itself has not been styled using css variables. Here is a simple codepen for the repro:

Repro Steps
This is the codepen that has the example
https://codepen.io/tomi-msft/pen/rNeMJYq?editors=1111

Open the codepen in a moder browser and observe that on hover, the div element's background turns white

Open this link in ie11(since codepen is not supported) and observe that the on hover styling is not applied:
https://codepen.io/tomi-msft/full/rNeMJYq