It is impossible in the framework of the task. Formulate the problem more specifically. Because of the width of the screen of the display device the visibility of objects holds. When I wrote the anti-spam for WordPress I standard entry form moved to 3000 pixels to the left, and not exposed :hidden, because some bots parse :hidden. From the point of view of the user is not visible neither. Another thing is if you need to find elements which never can be shown, that's a real challenge.