[Question] about the layout of the flet

[irx999]

Question

I guess it's always docked at the top, not when I change the size of a container，

If you can, please tell me how to stay at the top

Code sample

page1 = ft.Row([dy_tool_1,dy_tool_2],
                alignment=ft.MainAxisAlignment.CENTER,)
               
    page2 = ft.ElevatedButton(icon=ft.icons.SETTINGS,text= "页面2",on_click= lambda __: (setattr(page3, 'text', 123), page.update()))
    
    page3 = page0
    
    pagelist = [page0,
                page1,
                page2,
                page3]
    card = ft.Container(pagelist[0],alignment=ft.alignment.top_left,
                        # bgcolor= ft.colors.AMBER,
                        # height= 700,width= 1031,expand= False
                        )
    
    def modifyingPages(e):
        card.content = pagelist[e.control.selected_index+1]
        print(e.control.selected_index)
        page.update()
        
        
    

    rail = ft.NavigationRail(
        # selected_index=0,
        label_type=ft.NavigationRailLabelType.ALL,
        # extended=True,
        min_width=100,
        min_extended_width=200,
        leading=ft.FloatingActionButton(icon=ft.icons.DATASET_ROUNDED, text="主页面",on_click= lambda __: (setattr(card,"content",pagelist[0]),page.update())),
        group_alignment=1,
        destinations=[
            ft.NavigationRailDestination(
                icon=ft.icons.TIKTOK,
                selected_icon=ft.icons.TIKTOK_OUTLINED, label="抖音"
            ),
            ft.NavigationRailDestination(
                icon_content=ft.Icon(ft.icons.BOOKMARK_BORDER),
                selected_icon_content=ft.Icon(ft.icons.BOOKMARK),
                label="Second",
            ),
            ft.NavigationRailDestination(
                icon=ft.icons.SETTINGS_OUTLINED,
                selected_icon_content=ft.Icon(ft.icons.SETTINGS),
                label_content=ft.Text("Settings"),
            ),
        ],
        # on_change=lambda e: print("Selected destination:", e.control.selected_index),
        on_change= modifyingPages
        
    )

    return    ft.Row(
            [
                rail,
                ft.VerticalDivider(width=2),
                
                card
               
            ],
            expand=True,
            alignment= ft.MainAxisAlignment.START
        )

Error message

No response

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• I have searched for answers to my question both in the issues and in previous discussions.

[irx999]

我想设置成这样