How to target shadow root container padding in mushroom-card with card-mod?

The two buttons at the top right of this card are mushroom-template cards.
I’m trying to get them to be as simple a button as possible with just the icon affecting the spacing.


However, I can't figure out how to get at the padding that is applied to this container element. It has 10px on the top and the bottom.

Thanks for any insight!

I’ve tried a few things…
thought this might work, but no.

card_mod:
  style:
    ha-card$:
      mushroom-card$:
        mushroom-state-item$:
          div.container: |
            padding: 0 !important;

and

card_mod:
  style:
    ha-card$:
      mushroom-card$:
        mushroom-state-item$:
          '[class=" container "]': |
            padding: 0 !important;

no luck.

Any ideas?