How to style the individually selected handles?

As far as I understand, a line can have two style properties: either the line is selected, or it's unselected. The handles (points/nodes/bullets) you can move on the line can be styled as well, but it seems to be impossible to make a difference between a selected line and a selected handle ON the line. E.g. there is no visual difference between an entire line being selected, or a handle ON that line that is being selected. When the line is selected and you press the delete button, the entire line disappears. But when a handle is selected, ONLY that handle is deleted. That's fine. But how can we know if the entire line OR the handle is selected?

Start by reproducing the line-selection and handle-selection behavior described in the issue, including the different delete outcomes. Then trace how selected lines and handles are styled in mapbox-gl-draw; done means the two selection states have a visibly distinguishable styling without changing their deletion behavior.