How to hide picture type border

Hi,

I’m using the following code for a card where I’m working in these days:

id: odroidn2_status
type: custom:config-template-card
variables:
  - states['sensor.system_monitor_disk_use'].state
  - states['sensor.current_version'].state
  - states['sensor.system_monitor_memory_usage'].state
  - states['sensor.system_monitor_processor_use'].state
  - states['sensor.system_monitor_processor_temperature'].state
entities:
  - sensor.system_monitor_disk_use
  - sensor.current_version
  - sensor.system_monitor_memory_usage
  - sensor.system_monitor_processor_use
  - sensor.system_monitor_processor_temperature
card:
  type: entities
  title: Odroid N2
  entities:
    - type: custom:hui-element
      card_type: vertical-stack
      cards:
        - type: horizontal-stack
          cards:
            - type: picture
              card:
                - '--ha-card-border': 0px
              image: /local/images/odroidn2.png
            - type: custom:button-card
              layout: icon_name_state2nd
              show_icon: true
              show_state: true
              styles:
                grid:
                  - grid-template-columns: 50px auto
                icon:
                  - padding: 0px 0px
                  - height: 30px
                  - width: 30px
                card:
                  - '--ha-card-background': rgba(0, 0, 0, 0.0)
                  - '--ha-card-box-shadow': none
                  - '--ha-card-border-width': 0px
                state:
                  - padding: 0px 10px
                  - justify-self: start
                  - font-family: Roboto, sans-serif
                  - font-size: 15px
                name:
                  - padding: 0px 10px
                  - justify-self: start
                  - color: var(--secondary-text-color)
              entity: sensor.uptime
              name: Uptime
              icon: mdi:clock-outline
        - type: custom:bar-card
          show_icon: true
          align: split
          columns: 1
          max: 100
          positions:
            icon: inside
            indicator: inside
            name: inside
            value: inside
          unit_of_measurement: '%'
          severity:
            - value: 50
              color: '#3498db'
            - value: 75
              color: '#f39c12'
            - value: 100
              color: '#e45e65'
          style: |
            ha-card { 
                --paper-card-background-color: 'rgba(0, 0, 0, 0.0)';
                --ha-card-background: "rgba(0, 0, 0, 0.0)";
                --paper-item-icon-color: 'var(--text-primary-color';
                --ha-card-box-shadow: 'none';
            }
          entities:
            - entity: sensor.system_monitor_disk_use
          name: ${ 'Disk (' + vars[3] + 'Gb/' + vars[2] + 'Gb)' }
          entity_row: true
        - type: horizontal-stack
          cards:
            - type: custom:bar-card
              show_icon: true
              align: split
              columns: 1
              max: 100
              positions:
                icon: inside
                indicator: inside
                name: inside
                value: inside
              unit_of_measurement: '%'
              severity:
                - value: 50
                  color: '#3498db'
                - value: 75
                  color: '#f39c12'
                - value: 100
                  color: '#e45e65'
              style: |
                ha-card { 
                  --paper-card-background-color: 'rgba(0, 0, 0, 0.0)';
                  --ha-card-background: "rgba(0, 0, 0, 0.0)";
                  --paper-item-icon-color: 'var(--text-primary-color';
                  --ha-card-box-shadow: 'none';
                }
              entity: sensor.system_monitor_memory_usage
              name: RAM
              entity_row: true
            - type: custom:bar-card
              show_icon: true
              align: split
              columns: 1
              max: 100
              positions:
                icon: inside
                indicator: inside
                name: inside
                value: inside
              unit_of_measurement: '%'
              severity:
                - value: 50
                  color: '#3498db'
                - value: 75
                  color: '#f39c12'
                - value: 100
                  color: '#e45e65'
              style: |
                ha-card { 
                  --paper-card-background-color: 'rgba(0, 0, 0, 0.0)';
                  --ha-card-background: "rgba(0, 0, 0, 0.0)";
                  --paper-item-icon-color: 'var(--text-primary-color';
                  --ha-card-box-shadow: 'none';
                }
              entity: sensor.system_monitor_processor_use
              name: CPU
              entity_row: true
        - type: custom:mini-graph-card
          height: 30
          line_width: 2
          font_size: 70
          hours_to_show: 168
          points_per_hour: 1
          show:
            extrema: true
            fill: true
          style: |
            ha-card { 
              --ha-card-background: "rgba(0, 0, 0, 0.0)";
              --ha-card-box-shadow: 'none';
              border-radius: 5px;
            }
            .info.flex {
              font-size: 12px !important;
            }
          entities:
            - sensor.system_monitor_processor_temperature
          name: Temperature
          color_thresholds:
            - value: 30
              color: '#3498db'
            - value: 50
              color: '#f39c12'
            - value: 80
              color: '#ff0000'

Is there a way to hide the border of picture card? I tried some with ha-card (in the code you can see the last attempt) but with no success.

image

it has to be

card_mod:
  style: | 

Thank you.
I tried this yet but maybe I committed some syntax errors.
Now it works like this:

card_mod:
                style: |
                  ha-card { 
                    --paper-card-background-color: 'rgba(0, 0, 0, 0.0)';
                    --ha-card-background: "rgba(0, 0, 0, 0.0)";
                    --ha-card-box-shadow: 'none';
                    --ha-card-border-width: 0px !important;
                  }