Confused about theme css setting

hi,
using

  background-card-color: 'ivory' 
  border-radius: '6px'
  box-shadow: '0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19)'

in my theme, I get the color to show up on (almost) all cards (and buttons etc) and on most cards the border is set accordingly also.
on some though this isnt happening. Ive got several entities, and glance cards that show the color, but not the border. since they are not mentioned here https://github.com/thomasloven/lovelace-card-mod#why-wont-this-work-for-some-cards probably some other issue is at hand?

do I need the ha-card prefix for those, and if yes, why, or, when do I need this and when not. Not grasping why the color is accepted and the other settings aren’t…

even more confusing is even when using the above, the color isn’t accepted on a vertical-stack with horizontal-stack cards, but the border is styled…

lastly, using a transparent background image takes out the background coloring. Is a dedicated css setting available to overcome that? Or cant we use a background image alongside a colored background, without explicitly repeating these settings in the card:

  - type: entities
    style: |
      ha-card {
        background: url("/local/lovelace/images/party.png");
        background-size: cover;
        background-color: ivory;
      }

or, to proof the theme setting is correct, using:

  - type: entities
    style: |
      ha-card {
        background: url('/local/lovelace/images/party.png');
        background-size: cover;
        background-color: var(--paper-card-background-color);
      }

without the background-color line the background is default white…
please have a look for me? thanks!