Using Content Server's reader on an iPhone, when taking notes or typing any inputs in Preferences, Safari will automatically zoom in on the input fields for better visibility. Even when typing is done, the interface will stay zoomed and the book content now becomes cropped. Pinching on the screen does not zoom back the viewpoint, but changes the font size. I will have to activate the Menu and pinch on the menu section to make it zoom back to normal. Here's
a screenshot to be clear.
I did some research and found that iOS will auto zoom-in when the input field's font size is smaller than 16px. To prevent this, we can either change the font size to 16px or prevent zooming altogether. In Calibre's case, since pinching is for changing font sizes, maybe consider disabling zooming on the reader?
Here is the link I found:
Prevent iOS from zooming in on input fields