#shop_img {
	width:800px;
	margin:0 auto;
}
#shop_img li {
	margin:0 auto 30px;
	float: left;
	width:360px;
	height: 360px;

}
#shop_img li:nth-child(even) {
	float: right;

}
#shop_img li p {
	margin:15px auto 0;
}