Can't center two slides with a width of 1024 or less?

Question

Layout

https://codepen.io/roderen/pen/bGwygqG

Now above 1024px, the slider looks like this:


At 1024px and below it looks like this:


And it should look like this at 1024px and below:


I just can't figure out why I can't put two slides in the center...