html, body, div, span, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, abbr, address, cite, code, del, dfn, em, img, ins, kbd, q, samp, small, strong, sub, sup, var, b, i, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, figcaption, figure, footer, header, hgroup, menu, nav, section, summary, time, mark, audio, video {margin: 0;padding: 0;border: 0;font-size: 100%;box-sizing: border-box;}
article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section {display: block;}

html {
	font-size: 62.5%;
	-ms-text-size-adjust: 100%;
	-webkit-text-size-adjust: 100%;
	-moz-osx-font-smoothing: grayscale;
	-webkit-font-smoothing: antialiased;
	text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6, p, span, a, address, th, td, label, li {max-height: 100%;}

html body {
	color: #000;
	font-family: -apple-system, "Helvetica Neue", "Hiragino Sans", Helvetica, Arial, "Hiragino Kaku Gothic Pro", "ヒラギノ角ゴ ProN W3", "Roboto", "Droid Sans", "Meiryo UI", "Meiryo", "メイリオ", sans-serif;
	font-size: 14px;
	font-size: 1.4rem;
	line-height: 21px;
	line-height: 2.1rem;
}

/*----- Header -----*/
header {
	background-repeat: no-repeat;
	-moz-background-size:100% auto;
	background-size: 100% auto;
	padding-bottom: calc(100%*300/1280);
	background-position: center;

}
#index header, #en_index header {
	background-image: url(../img/screen1.jpg);
}
#contact header, #terms header, #about header {
	background-image: url(../img/screen2.jpg);
}
#link header {
	background-image: url(../img/screen3.jpg);
}
#glossary header {
	background-image: url(../img/screen4.jpg);
}
#unit_conversion header {
	background-image: url(../img/screen5.jpg);
}
header nav {
	width: 960px;
	margin: 0 auto;
	position: relative;
}
header nav ul {
	list-style: none;
	color: #FFF;
	font-size: 12px;
	position: absolute;
	right: 30px;
	padding-top: 10px;
}
header nav ul li {
	float: left;
}
header nav ul li:last-child {
	width: 104px;
	height: 26px;
	margin-left: 10px;
}
header nav ul li a {
	display: inline-block;
	text-decoration: none;
	color: #FFF;
}
header nav ul li a:hover {
	text-decoration: underline;
}
header nav div {
	position: absolute;
	width: 400px;
	color: #FFF;
	font-size: 36px;
	font-weight: bold;
	line-height: 200px;
	right: 0;
	left: 0;
	margin: auto;
	margin-top: 30px;
}

/*----- Main Contents -----*/
#main-contents {
	width: 960px;
	margin: 0 auto;
	position: relative;
	overflow: hidden;
}
#menu {
	background-color: #3d3b47;
	width: 100%;
	height: 80px;
	position: relative;
}
#menu nav {
	width: 960px;
	margin: 0 auto;
	position: relative;
}
#menu nav ul {
	width: 800px;
	height: 80px;
	list-style: none;
	margin: 0 auto;
}
#menu nav ul li {
	float: left;
	background-repeat: no-repeat;
	background-position: left 30px center;
}
#menu nav ul li a {
	display: block;
	width: 200px;
	height: 80px;
	text-decoration: none;
	color: #FFF;
	line-height: 80px;
	font-size: 14px;
	box-sizing: border-box;
	padding-left: 90px;
}
#menu nav ul li:first-child {
	background-image: url(../img/menu_icon1.png);
}
#menu nav ul li:nth-child(2) {
	background-image: url(../img/menu_icon2.png);
}
#menu nav ul li:nth-child(3) {
	background-image: url(../img/menu_icon3.png);
}
#menu nav ul li:last-child {
	background-image: url(../img/menu_icon4.png);
}
#menu nav ul li :hover, .selected {
	background-color: #D13672;
	background-repeat: no-repeat;
	background-position: left 30px center;
}
#menu nav ul li:first-child :hover {
	background-image: url(../img/menu_icon1-on.png);
}
#menu nav ul li:nth-child(2) :hover, #link .selected {
	background-image: url(../img/menu_icon2-on.png);
}
#menu nav ul li:nth-child(3) :hover, #glossary .selected {
	background-image: url(../img/menu_icon3-on.png);
}
#menu nav ul li:last-child :hover, #unit_conversion .selected {
	background-image: url(../img/menu_icon4-on.png);
}
h1 {
	color: #333;
	font-size: 18px;
	font-weight: bold;
	text-align: center;
	line-height: 70px;
}
#top_back {
	display: block;
	width: 38px;
	height: 38px;
	background-image: url(../img/top_back.png);
	margin: 40px 10px 10px auto;
}
#top_back:hover {
	background-image: url(../img/top_back2.png);
}
#top_back:active {
	background-image: url(../img/top_back3.png);
}

/*----- Footer -----*/
footer {
	background-color: #3d3b47;
	width: 100%;
	height: 40px;
	position: relative;
}
footer nav {
	width: 960px;
	margin: 0 auto;
	position: relative;
}
footer nav div {
	color: #FFF;
	margin: 0 auto;
	margin-left: 0;
	line-height: 40px;
	text-align: center;
}