We are already specifying the element's role ('all') in the HTML. Its behaviour should be predefined; there's no need to also specify in the HTML.
The eventhandler doesn't need to be cleand up on disconnect, because they are removed along with the DOM object.
- checked_controller close details element on checkboxes
- dropdown_controller.js is to rebuild controller from many divs
to be hidden and visible to an html detail elmnt one
- details html element styling
