@Jonathan So, what I want to do is move the old box so they are vertically centered no matter how much boxes there are. Basically I want to do the same thing the pen already does but I want to ease the movment of the div so it's not recalculating the position with flexbox. I linked a picture so you can understand better.
Hi, Each time I click on the button, I add a new (.box) in the list but I want to smooth the position of the others boxes (see my codepen) and still get the content vertically centered. As you can see I used flexbox. Thanks for the reply.