Empty "hidden" card still takes up space

[ScottG489]

Describe the bug
Card still takes up a small amount of space when it should be hidden. I believe we should apply a display: none style to the card. It looks like this was partially implemented with #360 to fix #359 (where I left a related comment).

How to reproduce
Create a card that has no displayed battery entities. It takes up a small amount of space due to margins (see screenshots below).

Expected behavior
Card should not only be hidden, but take up no space.

YAML configuration
N/A

Screenshots
auto-entities for comparison:

You can see the battery card next to another card with the element highlighted in dev tools:

That part highlighted in orange is due to a 4 pixel margin on the top and bottom. Small nitpick of course, but it adds a noticeable gap when nested between other cards.

Version
v2.1.1

[maxwroc]

Thanks for details. Indeed this could be fixed/improved

[maxwroc]

Fixed in v3