The ios keyboard zooms in the page when clicking on input field and the fixed div is pushed out of the screen

I am trying to use position fixed to work well on iOS devices.

This is how it looks when the keyboard has not opened:

No keyboard active For the above chat window I have used this piece of code:

    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;

When I tap the input box (to write a message), keyboard opens up and the top part becomes hidden with the screen zoomed in and it looks like this:

When Keyboard is active

I think ios is ignoring top: 0 when the keyboard opens up. What can I do to avoid that?

There is no issue as such on chrome.