UI position problem with animator

So I want to make a sliding image with buttons on it so that I don’t have to move every button one by one, but I used an animator to make the button slide left and right when tapping on a button. It worked but when I tested it on my phone the buttons didn’t slide far enough right and when I tested it on a tablet it slid out to far to the right. How will I make it end up on the same position on any phone or tablet?

Try Maximizing on Play to get the full Resolution or you can change the Aspect

Maximizing on Play shows what (tablets, phones, etc…) sees