* { box-sizing: border-box; }
#comic {
	position: absolute;
	top: 50%;
	left: 50%;
	width: 500px;
	height: 500px;
	margin-top: -250px; /* Half the height */
	margin-left: -250px; /* Half the width */
}
.hidden {
	visibility: hidden;
}
#loader {
	position: absolute;
	top: 50%;
	left: 50%;
}