The answer used to be absolutely yes because, if you used px units, you prevented the text from being resized by the user at all.
But browser zoom is the default method for making everything bigger (including text) these days and it works great even if you use px.
But... Kathleen McMahon really digs into this and finds that it's still worth setting all your type (both font-size and line-height) in relative units because:… Read article
