How can I style this light-popup-card as a popup window?

Configuration Frontend
1

I’m using a light-popup-card as a popup window. everything works but I want to add some extra padding below the slider.

Why isn’t this code working?

    hold_action:
      action: fire-dom-event
      browser_mod:
        command: popup
        title: >
          [[[ return entity === undefined || entity.attributes.friendly_name; ]]]
        card:
          type: custom:light-popup-card
          entity: >
            [[[ return variables.entity_id; ]]]
          icon: none
          fullscreen: false
          brightnessWidth: 130px
          brightnessHeight: 360px
          borderRadius: 1.7em
          sliderColor: '#c7c7c7'
          sliderTrackColor: rgba(25, 25, 25, 0.9)
          displayType: slider
          card_mod:
            style: |
              :host { padding: 1.2vw }