How can I edit the sizing and the submit button?

I am having trouble seeing the "my bag"button on options during shopping. I have had a few customers hit review and submit before and not knowing to scroll down.Please see uploaded screenshot of my concerns. Your help would be greatly appreciated!! 

I'm afraid that's not possible if you are going to use the direct URL of the form. Your users will have to use the scrollbar since its common with the card forms especially when the length of the card is high.

However, if you are embedded your form, you can customize it to get rid of the scrollbar.

When you embed your form and you are viewing it as admin, you should be able to see the customize button as shown in the following demo.

If you need further assistance, let us know.