Change .close -> .open in .grid-button 

Hello Sara! Bravo 4 your work!
I downloaded the zip version and it didnt work.
So I made these changes and now I think it works just fine.
(I also made changes to script in index.html in order to make it work) 
Change .close -> .open in .grid-button lines 99, 108, 116,
I hope I was helpfull.