Cleaner box shadow for .post in Snow White theme.

boards/static/css/sw/base_page.css

@@ -152,7 +152,7 b' li {'
     background: #FFF;
     padding: 1ex;
     border: 1px solid #666;
-    box-shadow: 1px 1px 2px 1px #666;
+    box-shadow: 2px 2px 0 0 #ccc;
 }
 
 #posts > .post:last-child {