Style call-service element with card-mod

Hi… I´m trying to make style to a call-service element with card-mod but no lucky…

this is my code:

- type: custom:hui-element
  card_type: conditional
  conditions:
	- entity: binary_sensor.omv_update_available
	  state: "off"
  card:
	type: custom:hui-element
	row_type: call-service
	name: Actualización Disponible?
	icon: mdi:download
	action_name: Actualizar OMV
	service: shell_command.actualizar_omv_script
	debug_cardmod: true
	style: 
	  $: |
		ha-icon {
		  color: yellow;
		  background-color: rgba(36, 42, 43, 1);
		  --paper-item-icon-color: red;
		}

and I´m trying to style “ha-icon” and “mwc-button” but not work…
any idea???

Thanks…