Would I know how I could do to visualize the squares well from the phone?

Would there be some CSS code to do it?

You can see the code and a sample of how I have made the pictures.

You should be able to make it responsive so the columns sit under each other depending on the media width.

@media screen and (min-width: 768px) {
  
  div {
    float: left;
    width: 200px;
  }
}

@judgerookie Thanks for the link, I’ll see if I can get the solution.