The email I wrote is able to adjust to portrait and landscape mode. But when turning from portrait mode to landscape mode, then back to portrait mode, I find the end result is the email has been downscaled a bit. Pinching and zooming all the way out fixes it, and the email is back to normal.

But I want to avoid zooming in and adjusting the email so it fits the whole screen. Is there a way to avoid having this issue using @media queries, or is this an iOS bug?