body
{
   font-family: Arial, Tahoma, Sans-Serif;
   font-size: 1em;
}

#Popup
{
   visibility: hidden;
   position: absolute;
   left: 50%;
   top: 50%;
   background-color: #000;
   padding: 10px;
}

#Overlay
{
   visibility: hidden;
   position: absolute;
   left: 0;
   top: 0;
   width: 100%;
   background-color: #000;
}
#Popup { z-index: 3; }
#Overlay { z-index: 2; }
#main { z-index: 1; }