Clear / Translucent Background

[Dhostetter]

Goal

I apologize if this has been answered already but I haven't been able to find the answer yet.
Is there a way to remove the background? i.e. Let the dashboard background pass through.
I just want to display the bubble card entities.
Please let me know.
Thanks

Source Yaml

type: custom:bubble-card
card_type: button
button_type: state
entity: sensor.raven_tire_pressure_front_left
show_name: false
show_state: true
tap_action:
  action: none
card_layout: normal
icon: mdi:tire
styles: |
  ha-card {
    background: rgba(0, 0, 0, 0.0);
    box-shadow: none;
  }

Which step did you already try?

This is what I tried.
type: custom:bubble-card
card_type: button
button_type: state
entity: sensor.raven_tire_pressure_front_left
show_name: false
show_state: true
tap_action:
  action: none
card_layout: normal
icon: mdi:tire
styles: |
  ha-card {
    background: rgba(0, 0, 0, 0.0);  # thought this would be fully transparent
    box-shadow: none;                # remove shadow 
  }

Problem

Had no effect

Read the documentation

• I have read the documentation

[Dhostetter]

Found it.
type: custom:bubble-card
card_type: button
button_type: state
entity: sensor.raven_tire_pressure_front_left
show_name: false
show_state: true
tap_action:
action: none
card_layout: normal
icon: mdi:tire

styles: |
/* safest: use the card's CSS vars */
:host {
--bubble-button-main-background-color: transparent;
--bubble-icon-background-color: transparent;
--bubble-box-shadow: none;
--bubble-border: none;
}