Text area scroll under header on mobile

Device: Google pixel 3
Browser: chrome
OS: Android

Steps to reproduce:. On mobile, when tapping into a text area (such as messaging someone, or typing in this exact box), the page will scroll up so that the scroll top will be aligned at the top of the text area. However, due to the header being positioned fixed, this scroll will bring the top part of the text area underneath the header.

Anything else to add:. Will need to take header height into account for the scroll action.