vertical stack

cards:
  - cards:
      - color_thresholds:
          - color: '#db0000'
            value: 90
          - color: '#008427'
            value: 60
          - color: '#0554ff'
            value: 0
        entities:
          - entity: sensor.dark_sky_temperature
        line_color: '#24722b'
        line_width: 3
        name: Outside
        type: 'custom:mini-graph-card'
    type: horizontal-stack
  - cards:
      - entities:
          - entity: sensor.1st_floor_temperature
        line_color: '#2980b9'
        line_width: 6
        name: 1st Floor
        type: 'custom:mini-graph-card'
      - entities:
          - entity: sensor.2nd_floor_temperature
        line_width: 6
        name: 2nd Floor
        type: 'custom:mini-graph-card'
      - entities:
          - entity: sensor.3rd_floor_temperature
        line_color: '#b93829'
        line_width: 6
        name: 3rd Floor
        type: 'custom:mini-graph-card'
    type: horizontal-stack
type: vertical-stack