@charset "UTF-8";


.ndoc li {
	float:left;
	position:relative;
	width:200px;
	height:200px;
	background-position:center center;
	background-size:cover;
	margin:0 30px 30px 0;
}
.ndoc li a {
	position:absolute;
	top:0;
	left:0;
	width:100%;
	height:100%;
	background-color:#fff;
	opacity:0;
	transition: opacity 0.5s;
}
.ndoc li a:hover {
	opacity:0.4;
}
.ndoc li:nth-child(4n) {
	margin-right:0;
}
@media screen and (max-width: 499px) {
.ndoc li {
	width:150px;
	height:150px;
	margin:0 20px 20px 0;
}
.ndoc li:nth-child(2n) {
	margin-right:0;
}
.ndoc li:last-child {
	margin-bottom:30px;
}
}