New File page file name field unclickable

Summary

In the "New File" page form, when narrow (mobile) view is used, "File name" field becomes unclickable.

Steps to reproduce

1. Go to a "New File" page in any repository
2. Adjust browser window to be narrow enough to trigger a narrow layout
3. Click on "File name" field

Example Project

https://gitlab.com/gitlab-org/gitlab/new/master

What is the current bug behavior?

"File name" field is unclickable.

What is the expected correct behavior?

"File name" field being clickable.

Relevant logs and/or screenshots

filename

Output of checks

This bug happens on GitLab.com. This happens on both Chrome and Firefox.

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)