body {
	background: #fff;
	margin: auto;
}

#wrap {
	margin: auto;
	width: 830px;
	padding-top: 50px;
}

#content {
	display: block;
 	width: 830px;
 	height: 450px;	
 	background: #fff url('background_logo.jpg') no-repeat 0 0;
}

#content:hover { 
 	background-position: 0 -461px;
}

#content span {
 	display: none;
}
#tweet {
	text-align: center;
}