Layout dashboard

Hi,

I want to create a new dashboard with three columns.
I started with this code:

views:
  - title: Huis
    path: huis
    type: custom:grid-layout
    layout:
      grid-template-columns: 33% 10% 1fr
      grid-template-areas: |
        "a1 a2 a3"
        "b1 b2 b3"
    subview: false
    theme: clear-dark
    badges: []
    cards:
      - type: vertical-stack
        cards:
          - type: markdown
            content: |-
              <font size="10">{{ states('sensor.today_time') }}</font>

              <font size="5">{{ states('sensor.today_day') }}</font>
      - type: vertical-stack
        cards:
          - square: false
            type: grid
            cards:
              - type: custom:button-card
                color_type: card
                name: Home
                styles:
                  card:
                    - background: transparent
                    - color: white
                    - height: 70px
                    - font-size: 25px
                border-radius: 50%
                tap_action:
                  action: navigate
                  navigation_path: /dashboard-thuis/home
              - type: custom:button-card
                color_type: card
                name: Verwarming
                styles:
                  card:
                    - background: transparent
                    - color: white
                    - height: 70px
                    - font-size: 25px
                border-radius: 50%
                tap_action:
                  action: navigate
                  navigation_path: /dashboard-thuis/verwarming
              - type: custom:button-card
                color_type: card
                name: Verlichting
                styles:
                  card:
                    - background: transparent
                    - color: white
                    - height: 70px
                    - font-size: 25px
                border-radius: 50%
                tap_action:
                  action: navigate
                  navigation_path: /dashboard-thuis/verlichting
              - type: custom:button-card
                color_type: card
                name: Zonnepanelen
                styles:
                  card:
                    - background: transparent
                    - color: white
                    - height: 70px
                    - font-size: 25px
                border-radius: 50%
                tap_action:
                  action: navigate
                  navigation_path: /dashboard-thuis/zonnepanelen
              - type: custom:button-card
                color_type: card
                name: Instellingen
                styles:
                  card:
                    - background: transparent
                    - color: white
                    - height: 70px
                    - font-size: 25px
                border-radius: 50%
                tap_action:
                  action: navigate
                  navigation_path: /dashboard-thuis/instellingen
              - type: custom:button-card
                color_type: card
                name: Camera's
                styles:
                  card:
                    - background: transparent
                    - color: white
                    - height: 70px
                    - font-size: 25px
                border-radius: 50%
                tap_action:
                  action: navigate
                  navigation_path: /dashboard-thuis/cameras
            columns: 4
        view_layout:
          grid-area: b1
      - show_name: true
        show_icon: true
        type: button
        tap_action:
          action: toggle
        entity: light.buitenverlichting
        name: Buitenverlichting
        view_layout:
          grid-area: a3

Creating the first column is ok:

Second column is just space.
By adding the third column it looks like this:

I do understand that the rowheight is the same for all the columns but is there a way i can adjust the rowheight for the third column ?