the-honkers-railway-launcher/assets/ui/preferences.blp

using Gtk 4.0;
using Adw 1;

Gtk.Box preferences {
    orientation: vertical;

    Adw.HeaderBar {
        title-widget: Adw.WindowTitle {
            title: "Preferences";
        };

        Gtk.Button preferences_go_back {
            icon-name: "go-previous-symbolic";
            halign: start;
        }
    }

    Adw.Flap {
        vexpand: true;
        
        flap: Gtk.StackSidebar {
            width-request: 200;
            stack: stack;
        };

        separator: Gtk.Separator {};
        content: Gtk.Stack stack {};
    }
}