[ui] i can't get padding right

[homebrewmellow]

look at the magenta box. see how the ImageNode isn't perfectly centered. i tried everything here is magenta block's code:

        par.spawn((
            Node {
                width: px(200),
                height: px(200),
                align_items: AlignItems::Center,
                justify_content: JustifyContent::Center,
                padding: UiRect::all(px(20)),
                margin: UiRect::all(px(10)),
                border_radius: BorderRadius::all(px(8)),
                flex_direction: FlexDirection::RowReverse,
                ..default()
            },
            BackgroundColor(color.into()),
        )).with_children(|par| {
            par.spawn((
                Node{
                    width: px(160),
                    aspect_ratio: Some(1.),
                    align_items: AlignItems::Stretch,
                    justify_content: JustifyContent::Stretch,
                    ..default()
                },
                children![
                ImageNode::new(img.clone())
                ],
            ));
        });