How can I relatively position an element, and have it not take up space in the document flow?
What you're trying to do sounds like absolute positioning. On the other hand, you can, however, make a pseudo-relative element, by creating a zero-width, zero-height, relatively positioned element, essentially solely for the purpose of creating a reference point for position, and an absolutely positioned element within that:
<div style="position: relative; width: 0; height: 0"> <div style="position: absolute; left: 100px; top: 100px"> Hi there, I'm 100px offset from where I ought to be, from the top and left. </div> </div>