Here’s screenshot from a form consisting of a custom controller and a tabpanel, nothing else.
The tab panel has a border set to empty. Still there’s a several pixel gap between it and the custom controller. Is there anything that can be done to simplify the join, make it less busy?
Here, let me answer my own question. If we can’t easily do that much with the tab panel, let’s change what it’s resting on.
Remove the border from the custom controller, give the custom controller, the tabpanel AND the form the tabpanel is resting on a slightly darker background than the form that constitutes the bulk of the rendered tab panel.