#main_area {
	background-image: url(../img/key.jpg);
}
.aboutintro {
	float: right;
	width: 460px;
	padding-top: 50px;
}
.back_building {
	background-image: url(../img/back_building.jpg);
	background-repeat: no-repeat;
	background-position: center top;
}
.greeting {
	float: left;
	width: 700px;
}
.name {
	text-align: right;
	font-weight: 600;
	font-size: 100%;
}
.name strong {
	font-size: 160%;
	font-family: "Hiragino Mincho Pro", "ヒラギノ明朝 Pro W3", "Kozuka Mincho Pro", "Kozuka Mincho Std", "小塚明朝 Pro R", "小塚明朝 Std R", "ＭＳ Ｐ明朝", "MS PMincho", serif;
	padding-left: 10px;
}
@media only screen and (max-width: 640px) {
	#main_area {
		-webkit-background-size: cover;
		background-size: cover;
	}
	.aboutintro {
		float: none;
		width: 100%;
		padding-top: calc((80/760)*100vw);
		padding-bottom: calc((200/760)*100vw);
		-webkit-box-sizing: border-box;
		-moz-box-sizing: border-box;
		box-sizing: border-box;
	}
	.back_building {
		background-position: center bottom;
		-webkit-background-size: calc((1000/760)*100vw);
		background-size: calc((1000/760)*100vw);
	}
	.greeting {
		float: none;
		width: auto;
	}
	.name {
		font-size: calc((26/760)*100vw);
	}
	.name strong {
		font-size: calc((50/760)*100vw);
		padding-left: calc((15/760)*100vw);
	}
}