body {
	background-image: url('images/bg.jpg');
	background-repeat: no-repeat;
	background-attachment: fixed;
	background-position: center; 
}
.center {
	width: 500px;
	height: 500px;
	position: absolute;
	left: 50%;
	top: 50%; 
	margin-left: -250px;
	margin-top: -250px;
}

.logo-image-holder {
    width: 100%;
    height: 100%;
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center center;
    transition: .3s;
}

.logo-image-holder:hover {
    opacity: 1.0;
    transform: scale(1.1);
}