Well maybe not final! I put up the restyled Billing Manager so @robert.down maybe would want to look at so you may see results while reviewing styling code.
Unfortunately bootstrap tables do not lend well to page layouts and I had to strike a compromise between html tables and bootstrap (Should convert to grid but ran out of steam). I can add a container responsive div if we want the billing detail table(bottom) full screen but, I landed on entire form in one container. Just looks better to me. I also set up button groups for the three action areas(X12,HCFA and UB04). Consolidating these seemed reasonable.
Code is cleaned up and ready for PR hopefully tomorrow.
Thanks