THANKS JFB

Small screen mainly for smart phones

As the device is rotated from portrait to landscape and vice versa this page should scale up or down to make use of the entire screen real estate.

Medium-size screen mainly for tablets

As the device is rotated from portrait to landscape and vice versa this page should scale up or down to make use of the entire screen real estate.

Large screen mainly for desktops and laptops

Larger screens are assumed to be laptops and desktops. Consequently it makes no sense to distguish between portrait and landscape orientations. What will happen in a year or two when tablets have pixel counts greater than or equal to that of laptops and desktops? That is when REAL fun for web developers will begin.