t the arrow keys are available for directional navigation within the menubar and its submenus, a border is added to the menubar container when focus is within the menubar.</li>
          <li>
            Like most desktop menubars, submenus open on mouse hover over a parent item in the menubar only if another submenu is already open.
            That is, if all submenus are closed, a click on a parent menu item is required to display a submenu.
            Minimizing automatic popups triggered by hover make