I've just upgraded from 12.2 to 13.1 and have lost the previous fivealive-lite screen width that would expand to as-wide-as HD monitors. I've looked in the fivealive-lite.css file and found a new set of max-width statements around line 5650 - with the largest being 1199px . This number seems to coincide with the max-width displayed on the screen. Unfortunately, I do not know how to fine-tune this for larger numbers.
Any suggestions would be appreciated.