How to add a scroll bar to a series of nested cards?

Hi, this is my first foray into using home assistant and CSS, and I’m trying to add a scroll bar to a bunch of cards I’ve stacked on top of each other on the left side of the sidebar layout. I’ve tried to use card-mod with the code below after reading throught the documentation, but I can’t seem to get it to work. Does anyone have any suggestions?

views:
  - title: Home
    sections: []
    type: sidebar
    cards:
      - type: custom:clock-weather-card
        entity: weather.forecast_home
        view_layout:
          position: sidebar
      - type: custom:card-mod
        style:
          ha-card:
            max-height: 80vh;
            overflow-y: auto;
            scrollbar-width: none;
        card:
          type: vertical-stack
          cards:
            - type: vertical-stack
              cards:
                - type: custom:week-planner-card
                  calendars:
                    - entity: calendar.NAME
                      color: blue
                      name: NAME
                    - entity: calendar.holidays_1
                      color: green
                      name: Holidays
                      hideInLegend: true
                    - entity: calendar.holidays_2
                      color: green
                      name: Holidays
                    - entity: calendar.NAME
                      color: red
                      name: NAME
                    - entity: calendar.NAME
                      color: purple
                      name: NAME
                  weather:
                    showTemperature: true
                    showLowTemperature: true
                    showCondition: true
                    entity: weather.forecast_home
                  days: 14
                  noCardBackground: true
                  locationLink: https://www.google.com/maps/search/?api=1&query=
                  locale: en
                  texts:
                    noEvents: No Events Today
                    fullDay: Full Day
                    today: Today
                    tomorrow: Tomorrow
                  showDescription: true
                  showLocation: true
                  startingDay: sunday
                  showLegend: true
                  card_mod:
                    style: |
                      .day.past {
                        opacity: .3;
                      }
                      .event[data-entity="calendar.NAME"] {
                        background-color: rgba(0, 0, 255,.2) !important;
                      }
                      .event[data-entity="calendar.holidays"] {
                        background-color: rgba(0, 128, 0,.2) !important;
                      }
                      .event[data-entity="calendar.holidays"] {
                        background-color: rgba(0, 128, 0,.2) !important;
                      }
                      .event[data-entity="calendar.NAME"] {
                        background-color: rgba(106, 90, 205,.2) !important;
                      }
                      .event[data-entity="calendar.NAME"] {
                        background-color: rgba(255, 0, 0,.2) !important;
                      }
                - square: false
                  type: grid
                  cards:
                    - camera_view: live
                      alert_classes:
                        - motion
                        - moisture
                      sensor_classes:
                        - temperature
                        - humidity
                      type: area
                      area: front_door
                      aspect_ratio: '3:4'
                      show_camera: true
                    - type: vertical-stack
                      cards:
                        - camera_view: live
                          alert_classes:
                            - motion
                            - moisture
                          sensor_classes:
                            - temperature
                            - humidity
                          type: area
                          area: front_yard
                          show_camera: true
                        - alert_classes:
                            - motion
                            - moisture
                          sensor_classes:
                            - temperature
                            - humidity
                          type: area
                          area: sideyard
                    - type: vertical-stack
                      cards:
                        - camera_view: live
                          alert_classes:
                            - motion
                            - moisture
                          sensor_classes:
                            - temperature
                            - humidity
                          type: area
                          area: driveway
                          show_camera: true
                        - camera_view: live
                          alert_classes:
                            - motion
                            - moisture
                          sensor_classes:
                            - temperature
                            - humidity
                          type: area
                          area: living_room
                          show_camera: true
                  title: Cameras
                  columns: 3
                - type: horizontal-stack
                  cards:
                    - type: thermostat
                      entity: climate.hallway
                      features:
                        - type: climate-hvac-modes
                    - type: entities
                      entities:
                        - fan.winix_office
                        - sensor.winix_office_aqi
                        - sensor.winix_office_filter_life
                        - fan.winix_kitchen
                        - sensor.winix_kitchen_aqi
                        - sensor.winix_kitchen_filter_life
                        - fan.winix_living_room
                        - sensor.winix_living_room_aqi
                        - sensor.winix_living_room_filter_life
                  title: Home Controls
      - type: todo-list
        entity: todo.my_tasks
        title: To Do
        hide_completed: true
        view_layout:
          position: sidebar

Perhaps one of these?

I use the former.

This looks like a promising alternative. I’ll give it a shot, thanks.

In your code only the 1st & 3rd card have “position: sidebar” set, not that huge vertical-stack.
So, it is unclear what “stacked” cards you wish to scroll.

This is a wrong card-mod code, should be like

      - type: custom:mod-card
        card_mod:
          style:
            xxx {
              ...
            }
        card:

If you choose a “scrollable sidebar” way - suggest to ask in card-mod-theme thread. Solution was posted here.