How can I set the width of a div for any monitor?
The most reliable way to ensure that HTML elements are sized according to the canvas area of users’ Web browser, whatever their monitor resolution, is to use percentage length units. The overall width of an HTML element is also affected by any margin, border and padding that is set. If you choose to use 100% width for an element, you should ensure that the margin, border and padding properties are set to zero or you will get horizontal scrolling.