Showing a focus indicator on a slider

Godot Version

4.7.1 (Mac)

Question

Could anyone tell me how to style the slider? I have ben playing with the theme editor for a while and I can set the color for the slider itself, but not for the “unused” portion (ie the percentage of the slider not selected). Also, is there a way to indicate focus on a slider (When using a game controller for example)

Thanks

Ok I worked it out. Its the grabber that shows the focus. There is no larger focus box.