Advanced Thermostat card merge problem

Hello,

For the creation of a Advanced Thermostat card, I want to merge a mini-graph card with a button-card. The YAML code so far:

type: custom:button-card
name: Test
styles:
  grid:
    - grid-template-areas: "\"temp\" \"n\""
    - grid-template-columns: 1fr
    - grid-template-rows: 65% 1fr
  card:
    - height: 160px
    - padding: 6px
  name:
    - justify-self: start
    - align-self: start
    - font-size: 14px
    - padding-left: 20px
  custom_fields:
    graph:
      - position: absolute
      - width: 100%
      - left: 0
      - bottom: 0
    temp:
      - justify-self: start
      - align-self: end
      - font-size: 2.6em
      - font-weight: 300
      - padding-left: 20px
custom_fields:
  graph:
    card:
      type: custom:mini-graph-card
      entities:
        - entity: sensor.netatmo_weather_station_indoor_temperature
          color: "#ffffff"
      line_width: 0
      height: 60
      show:
        icon: false
        name: false
        state: false
        legend: false
        labels: false
      card_mod:
        style:
          ha-card {border-style: none;background:none;}
  temp: >
    [[[

    return
    Number(states['sensor.netatmo_weather_station_indoor_temperature'].state).toFixed(1)
    + '°C ' + '<span style="font-size: 14px">' + 
    Number(states['sensor.netatmo_weather_station_indoor_humidity'].state).toFixed(1)
    + '%</span>'

    ]]]

Current result:

Desired result:

How do I get the desired result without the line between the two cards?