I have also had an issue like this. I have coded for window size but the gmail app on ios doesn't respect the media queries, you have to use inline values, ie. width="" padding="" and the gmail app itself has a smaller window on some iphones compared to other ESP apps on the same phone, so it squishes emails slightly. VERY frustrating. What worked for me, specifically I was having issues with div widths, was using percentage values for the width and having them only equal 99% instead of 100%. That extra 1% throws everything off. :( Hope this is helpful!