body {
	background: url(../images/bg.jpg) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
  



	margin: 0 auto;

}

.box img {

   width: 100%;
   max-width: 900px; /*actual image width*/
	max-height: 100%; /* responsive image */
	position: absolute; 
	top: 0; 
	right: 0; 
	bottom: 0; 
	left: 0; 
	margin: auto; /* center horizontally and vertically */

  
}