body {
  background: url('../img/SF_Website_BG-1_1920x1440.jpg') no-repeat center center fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  background-size: cover;
  -o-background-size: cover;
  height: 100%;
}

#main {
	color: #FFF;
	font-family: 'Roboto', sans-serif;
	text-align: center;
}

.center {
   width: 300px;
   height: 300px;
   position: absolute;
   left: 50%;
   top: 50%; 
   margin-left: -150px;
   margin-top: -150px;
}