div.box{
	width: 100vw;
	height: 100vh;
	background-size: cover;
	background-position: center;
	background-image: url('../image/top.jpg');
	
	display: -webkit-box;
	display: -ms-flexbox;
	display: flex;

	/* 左右中央寄せ */
	-webkit-box-pack: center;
	-ms-flex-pack: center;
	justify-content: center;

	/* 上下中央寄せ */
	-webkit-box-align: center;
	-ms-flex-align: center;
	align-items: center;

	padding: 30px;
	box-sizing: border-box;
}