Back button alignment

HTML & CSS
1

Here is my code in jsfiddle .

I want to put pay and back button …right below 200.

I don’t think center align would be good here …can we have a better alternative to align it ?

please don’t change existing css because these css are common and used elsewhere. However I can add new styles to use anyway.

2

Why not just add another double-cell row beneath due amount | 200 ?

3

wonderful. worked fine.

Thanks