ac.json

{
    "type": "AdaptiveCard",
    "version": "1.5",
    "layouts": [
        {
            "type": "Layout.AreaGrid",
            "targetWidth": "AtLeast:Standard",
            "columns": [
                {
                    "physicalSize": 100,
                    "unit": 0
                }
            ],
            "areas": [
                {
                    "name": "area1"
                }
            ]
        }
    ],
    "body": [
        {
            "type": "ColumnSet",
            "grid.area": "area1",
            "style": "emphasis",
            "showBorder": true,
            "roundedCorners": true,
            "columns": [
                {
                    "type": "Column",
                    "items": [
                        {
                            "type": "TextBlock",
                            "text": "Area 1",
                            "wrap": true
                        },
                        {
                            "type": "TextBlock",
                            "text": "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
                            "wrap": true
                        }
                    ],
                    "width": "stretch"
                }
            ]
        }
    ],
    "$schema": "https://adaptivecards.io/schemas/adaptive-card.json"
}