Resolutions Vary a Lot
Apple 27" High Resolution 2560-by-1440

But Most PC Monitors are Now 1080P 1920x1080
PC Low End 1366x768

Three Div Blocks Scaled Relative Size of Main Browser Window

• Tablet 1024x768 (53% by 71%)
• Smart Phone 640x480 (33% by 44%)
• Cell Phone 320x200 (16% by 18%)