7.1 Change Grid to single column in mobile .. I've tried EVERYTHING!

I've tried every code and fix in every thread I could find, and none of them did the trick for me. I have a grid of 3 images that I need in a single column when in mobile .. pretty common issue, but I have a feeling it's some of my other custom code that's keeping anyone's previous suggestions from working? No idea. 

Check it out here: https://ellen-wise-couture.squarespace.com/

password: ellen

It's at the bottom of the home page under where it says 'Explore The Creations'

Thank you!!!

So strange. I have tried that code and it didn't work in the past -- gave me very broken imagery (see screenshot), yet when I go full-screen, it now works. Perhaps the code worked all along and it's SS's mobile preview that's broken?

Either way - thank you for your help.

1 hour ago, mattchait said:

So strange. I have tried that code and it didn't work in the past -- gave me very broken imagery (see screenshot), yet when I go full-screen, it now works. Perhaps the code worked all along and it's SS's mobile preview that's broken?

Either way - thank you for your help.

Did you check it on your mobile phone? I have checked and its prefect. 

I did. Yes, it IS perfect and totally works. That's what I'm saying is so weird ... 

On the back end, when I add the code on the left, it breaks the site on the right. But it works for the rest of the world .. so whatever!