title: Round div height to the nearest even number if it has an odd value
body: <p>Basically I want to use transformY but the subpixel blur is very annoying and only occurs when the div is an odd height. As the height depends on the text viewport etc, need this to be flexible so realistically need it to get the height of the div - Divide it by 2, round to the nearest number then x 2 so it'd always produce an even value.</p>