javascript - Round div height to the nearest even number if it has an odd value -

Basically I want to use Transform Y but sub pixel blur is very upset and only occurs when div is a strange height. As the height text depends on the viewport, etc., it must be flexible so that it needs to actually get it to the height of the div, let it be 2 to two, then round the nearest number then x 2 then it is always a Will produce value.