That is a nifty site, Larry, thank you.
EGeographia, your English is just fine!
The way I did this was go to Atahualpa Theme Options / HTML and CSS Inserts (near the bottom of the page)
and put this in the white area at the bottom of that page:
-moz-box-shadow: 0 5px 3px 10px #5a98cb;
-webkit-box-shadow: 0 5px 3px 10px #5a98cb;
box-shadow: 0 5px 3px 10px #5a98cb;
This is similar to Larry's but I made the shadow blue. You can see it here: