Screen and Viewport Dimensions
Javascript is used here to calculate, in pixels, the dimensions of the screen and the viewport used by the browser. For the latter, two measures are used: one from the document element and the other from the window element. On a desktop screen, the sizes change dynamically when resizing the browser window or zooming in. On a mobile phone, the dimensions change when rotating the screen, but not when zooming in.
screen.width unknown
screen.height unknown
document.documentElement.clientWidth unknown
document.documentElement.clientHeight unknown
window.innerWidth unknown
window.innerHeight unknown