This should show, even though it is inside shadow DOM.
Popup 1
This popup can never be visible:
Hiding this popup will hide *all* open popups,
because t2b2 doesn't exist in this context.
And since popup 1 is not shown, it is display:none,
which means no child content is shown at all.
This popup will be hidden when popup2 shows.
This should not get hidden when popup2 opens.
This should not hide popup1.