box shadow

gistfile1.txt

const Gtk = imports.gi.Gtk;

Gtk.init(null);

let frame = new Gtk.Frame({
    expand: false,
    margin: 30
});
frame.set_size_request(200, 100)

frame.get_style_context().add_class('shadow')

let css = ".shadow {background-color:red; border: 2px solid blue; box-shadow: 0px 1px 20px 0px alpha(black, 0.5); padding: 10px;}"

let provider = new Gtk.CssProvider();
provider.load_from_data(css);
let context = frame.get_style_context();
context.add_provider(provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);


let mwindow = new Gtk.Window({
    default_width: 800,
    default_height: 600
});
mwindow.add(frame);
mwindow.show_all();
mwindow.connect('destroy', function() { Gtk.main_quit() });

Gtk.main();