html {
    height: 100%;
}
body {
	background-color:#6f298c;
	padding:0;
	margin:0;
	width:100%;
	background-image:url(../images/logo-white.png);
	background-position:50% 50%;
	background-repeat:no-repeat;
	min-height:100%;
}
body.grey {
	background-image:url(../images/logo.png);
	background-color:#ddd;
}