Previously in order to close the popup window at SO you needed to click at any place of the popup. It was fast, easy and convenient.
Now in the new design I need to search for
X button to do that, otherwise the popup will be opened constantly. It irritates me! Moreover, the "Close" button merges with the background, and I'm sure the people with weak eyesight will support me.
I think it is better to get rid of "Close" buttons and get back to previous functionality.