card_mod: styling unavailability

[Krzysztonek]

I need to add a rounded border to this card. When trying to use card_mod styles, like:

type: custom:timer-bar-card
card_mod:
  style: |
    ha-card {
      background-color: var(--primary-background-color);
      border-color: lime;
      border-radius: 5%
    }
icon: mdi:sprinkler
(...)

this whole card_mod section is never being saved in the card editor and it simply disappears from the card code.
Any hint on how to use such a way of styling, please?

[rianadon]

I changed the editor in the latest version, which could be the culprit.

If you click "Show Code Editor" at the bottom left corner, then add the card_mod section, does it get saved?