Portfolio 21 day challenge - project pages responsiveness

I am trying to follow the Portfolio 21 day challenge course and I have gotten to the project pages responsiveness video. Trying to use flexbox grow to make all of my div blocks grow but it is not working. I have cloned the tutorial and compared mine to the cloned project and cannot see any difference.

I have applied flexbox to my link block and I have applied flexbox grow to the child div block but the div block does not grow.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)