Can't get Card-Mod to work

I try to remove the boarders from card, and remove background color in cards, I found this thread about card-mod to do that.

But card-mod does not work .
I have installed card-mod with HACS.
In configuration.yaml added:

# Load frontend themes from the themes folder
frontend:
  themes: !include_dir_merge_named themes
  extra_module_url:
    - /local/community/lovelace-card-mod/card-mod.js

(The js is at \config\www\community\lovelace-card-mod\card-mod.js)

This is the code I try to use:

style: |
  ha-card {
     border-width: 0px !important;
     background: none
  }

The view with code:

  - title: SØBO
    path: sobo
    subview: true
    background: '#e5edf8'
    cards:
      - type: picture
        style: |
          ha-card {
             border-width: 0px !important;
             background: none
          }
        image: /local/media/sobo_medlemsbevis_flemming.png
        tap_action:
          action: none
        hold_action:
          action: none
      - type: markdown
        style: |
          ha-card {
             border-width: 0px !important;
             background: none
          }
        content: >-

          Liste over medlemsfordeler:
          [Medlemsfordeler](https://sobo.fordelerformedlemmer.no/)


          Fordeler hos Byggmakker, Monter, Peppes Pizza, Bohus, Kilden, Thon,
          Avis, med flere.

How it looks, still boarders, and background in the markdown card:

Did I do wrong?

use

card_mod:
  style: |