body {
background-color: black;
}
#main{
  width:900px;
  position: absolute;
  left:50%;
  top:50%;
  margin-left: -450px;
  margin-top: -300px;
  height:600px;
}
#logo_start{
  position:absolute;
  z-index:2;
  left:50%;
  top:50%;
  margin-left:-445px;
  margin-top:-77px;
  border:0;
}

#bg{
  top:50%;
  left:50%;
  position:absolute;
  z-index:1;
  width:900px; 
  margin-left: -450px;
  margin-top: -300px;
  height:600;
}