How is horizontal / vertical and game-object size best dealt with?

Hi

Do device/browser games verify what the venue (desktop/tablet/phone) being played on is to assist with GUI and UI?

My gameplay will obviously be different for various venues.
My game will need a different structure based on horizontal /vertical, tablet/desktop and doing percentages of width and height won't be perfect, also considering sprite and font sizes. Think of a solitaire spread across a phone top edge versus device top edge (longer) or desktop. Some games are much better turned on their sides. The card sizes would need to adjust, also.
How is horizontal / vertical layout and game-object size best dealt with? I am using Javascript.

Thanks