On condition blinking box shadow of entities card

Configuration Frontend
1

I have following conditional card:

    - type: conditional
      conditions:
      - entity: input_boolean.pool
        state: 'on'
      card: 
        type: entities
        style: |
                ha-card {
                  background: none;
                  font-variant: small-caps;
                } 
        entities:
            !include templates/cards/pool_timer.yaml

I would like to have animated (blinking) entities box shadow on condition - either sensor or input_boolean state.
Any advice pls?