Get some wide angle lens LEDs and place them on the bottom center. May need to play with the quantity to get the brightness you are looking for. The frosted/white acrylic should distribute enough at that distance
to keep from seeing hot spots but you may have shadows in the corners. EDIT: you...
I keep a printed copy of the US Constitution beside my desk just for telemarketers. I start reading it and talking over them as fast as I can. So far I have made it all the way to Article 2 before being hung up on.
Most only get a few sentences in before they give up.