:root {
	--content-box-padding: 2rem;
	--font-size-small: 85%;
	--font-family-gothic: "Noto Sans JP", "游ゴシック Medium", "Yu Gothic Medium", YuGothic, "游ゴシック体", sans-serif;
	--font-family-mincho: "Noto Serif", "游明朝", YuMincho, "Hiragino Mincho ProN W3", "ヒラギノ明朝 ProN W3", "Hiragino Mincho ProN", serif;
}

html, body {
	font-size: 16px;
	color: #555;
	font-family: var(--font-family-gothic);
	line-height: 1.5;
}

a {
	text-decoration: none;
}

a:hover {
	opacity: 0.75;
}

div {
	box-sizing: border-box;
}

img {
	max-width: 100%;
	height: auto;
	vertical-align: bottom;
}

header {
	width: 100%;
	max-width: 1920px;
	margin: 0 auto;
	text-align: center;
}

main {
	width: 100%;
	max-width: 1920px;
	margin: 0 auto;
}

section .container {
	width: 90%;
	max-width: 960px;
	margin: 0 auto;
	padding: var(--content-box-padding) 0;
	background: #fff;
}

section .container > * {
	width: 80%;
	margin-left: auto;
	margin-right: auto;
}

section h2 {
	margin: calc(var(--content-box-padding) / 2) 0 var(--content-box-padding) 0;
	text-align: center;
}

section h3 {
	margin: var(--content-box-padding) 0;
	text-align: center;
}

section p {
	margin-bottom: calc(var(--content-box-padding) / 2);
}

section p:last-child {
	margin-bottom: 0;
}

section .box {
	display: grid;
	gap: var(--content-box-padding);
}

section .btn {
	display: block;
	margin-top: var(--content-box-padding);
	text-align: center;
}

/* greeting */


/* event */
section.event .container {
	padding-top: 0;
	background: #124949;
}

section.event h2 {
	width: 100%;
	margin-top: 0;
}

/* willget */


/* speaker */
section.speaker .container {
	padding-top: 0;
	background: #124949;
	color: #fff;
}

section.speaker h2 {
	width: 100%;
	margin-top: 0;
}

section.speaker .speakers,
section.speaker .speaker_list li {
	position: relative;
	padding-top: 2rem;
}

section.speaker .speakers {
	font-family: var(--font-family-mincho);
	text-align: center;
}

section.speaker .speakers dt {
	color: #DEC178;
	font-size: 135%;
}

section.speaker .speakers dd {
	margin-bottom: calc(var(--content-box-padding) / 2);
}

section.speaker .speakers dd:last-child {
	margin-bottom: 0;
}

section.speaker .speaker_list {
	width: 100%;
}

section.speaker .speaker_list li {
	list-style: none;
}

section.speaker .speaker_list li h3 {
	margin: var(--content-box-padding) 0 0 0;
}

section.speaker .speaker_list li > div {
	width: 80%;
	margin: var(--content-box-padding) auto 0 auto;
}

section.speaker .speaker_list li::after {
	content: "";
	position: absolute;
	top: 1.75rem;
	left: 0;
	width: 100%;
	height: 0.5rem;
	border-top: 1px solid #80aaa9;
	border-bottom: 1px solid #80aaa9;
}

/* program */
section.program .container {
	padding-top: 0;
	background: #124949;
}

section.program h2 {
	width: 100%;
	margin-top: 0;
}

/* recommend */
section.recommend {
	padding-bottom: var(--content-box-padding);
}

section.recommend .container {
	padding-top: 1px;
}

section.recommend h2 {
	margin-bottom: calc(var(--content-box-padding) / 2);
}

/* ticket_image */
section.ticket_image {
	width: 100%;
}

section.ticket_image * {
	margin: 0;
	padding: 0;
}

section.ticket_image .container,
section.ticket_image .container > * {
	width: 100%;
	max-width: 100%;
}

/* ticket */
section.ticket .container {
	background: #124949;
}

section.ticket .container:first-child {
	padding-top: 0;
}

section.ticket .container:nth-child(2n+2) {
	background: #f0f0f0;
}

section.ticket h2 {
	width: 100%;
	margin-top: 0;
}

section.ticket .btns {
	display: grid;
}

section.ticket .btns li {
	list-style: none;
}

/* join */
section.join {
	padding: 1px 0 var(--content-box-padding) 0;
}

section.join .container {
	margin-top: var(--content-box-padding);
}

section.join .container:nth-of-type(2) {
	background: #124949;
}

section.join .container:nth-of-type(2) .btn {
	margin-bottom: var(--content-box-padding);
}

section.join .container:nth-of-type(3) {
	padding-top: 0;
}

section.join .container:nth-of-type(3) h2 {
	width: 100%;
	margin-top: 0;
}

/* about */
section.about {
	font-family: var(--font-family-mincho);
}

section.about .info dt {
    float: left;
    width: 6.5em;
	margin-left: calc(var(--content-box-padding) * 1.5);
	padding-top: 0.75em;
    clear: left;
}

section.about .info dt:after {
    content: "：";
	display: inline-block;
	width: 1rem;
}

section.about .info dt span {
    display: inline-block;
	width: calc(100% - 1rem);
	margin-left: auto;
	text-align: justify;
	text-align-last: justify;
}

section.about .info dd {
    padding: 0.75em calc(var(--content-box-padding) * 1.5) 0.75em calc(6.5em + calc(var(--content-box-padding) * 1.5));
	border-top: 1px solid #333;
}

section.about h2 {
	color: #124949;
}

section.about .iframe_wrap {
	position: relative;
	display: block;
	width: 100%;
	padding-top: 56.25%;
}

section.about iframe {
	position: absolute;
	display: block;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
}

section.about .faq dt {
	margin-top: calc(var(--content-box-padding) / 2);
	background: #fafafa;
	line-height: 1.5rem;
}

section.about .faq dt a {
	position: relative;
	display: block;
	padding: 0.5rem 2.5rem 0.5rem 3rem;
	color: #333;
	font-weight: bold;
}

section.about .faq dt a:before,
section.about .faq dt a:after {
	position: absolute;
	top: 0;
	width: 2.5rem;
	height: 2.5rem;
	line-height: 2.5rem;
	text-align: center;
	font-weight: normal;
}

section.about .faq dt a:before {
	content: "Q";
	left: 0;
	font-size: 1.5rem;
	color: #fff;
	background: url(./images/faq_q_bg.jpg) no-repeat center center;
	background-size: cover;
}

section.about .faq dt a:after {
	content: ">";
	right: 0;
	transform: rotate(90deg);
}

section.about .faq dt.open a:after {
	transform: rotate(-90deg);
}

section.about .faq dd {
	display: block;
	background: #fafafa;
	padding: 0.5rem 2.5rem 0.5rem 3rem;
	font-size: 13px;
	display: none;
}

section.about .faq dt.open + dd {
	display: block;
}

footer {
	width: 100%;
	max-width: 1920px;
	margin: 0 auto;
	background: #124949;
	color: #fff;
	text-align: center;
}

footer .container {
	width: 90%;
	margin: auto;
	padding: var(--content-box-padding) 0;
	font-size: 80%;
	line-height: 2;
}

footer nav li {
	position: relative;
	list-style: none;
}

footer nav li:after {
	content: "|";
	position: absolute;
	top: 0;
	bottom: 0;
	right: -1.5rem;
	width: 1em;
	height: 1em;
	line-height: 1em;
	margin: auto;
}

footer nav li:last-child:after {
	display: none;
}

footer a {
	color: #fff;
}

@media screen and (min-width: 800px) {
	section .box {
		grid-template-columns: repeat(2, 1fr);
	}

	section.greeting {
		padding: var(--content-box-padding) 0;
		background: #e0e0e0 url(./images/greeting_bg.jpg) repeat top center;
		background-size: contain;
		background-attachment: fixed;
	}

	section.greeting .box {
		grid-template-columns: 1fr 0.85fr;
	}

	section.greeting .box > :first-child {
		grid-row: 1;
		grid-column: 2;
	}

	section.event {
		background: #fff url(./images/event_bg.jpg) no-repeat top center;
		background-size: cover;
		background-attachment: fixed;
	}

	section.willget {
		padding: var(--content-box-padding) 0;
		background: #fff url(./images/willget_bg.jpg) no-repeat center center;
		background-size: cover;
		background-attachment: fixed;
	}

	section.speaker {
		padding: 0 0 var(--content-box-padding) 0;
		background: #124949 url(./images/speaker_bg.jpg) no-repeat top center;
		background-size: cover;
		background-attachment: fixed;
	}

	section.speaker .speaker_list li {
		font-size: 80%;
	}

	section.program {
		padding: var(--content-box-padding) 0;
		background: #fff url(./images/program_bg.jpg) repeat top center;
		background-size: contain;
		background-attachment: fixed;
	}

	section.recommend {
		background: #fff url(./images/recommend_bg.jpg) repeat top center;
		background-size: contain;
		background-attachment: fixed;
	}

	section.ticket {
		padding-bottom: var(--content-box-padding);
		background: #fff url(./images/ticket_bg.jpg) repeat top center;
		background-size: contain;
		background-attachment: fixed;
	}

	section.ticket .btns {
		grid-template-columns: 1fr 1fr 1fr 1fr;
		gap: 1px;
	}

	section.join {
		background: #fff url(./images/join_bg.jpg) repeat top center;
		background-size: contain;
		background-attachment: fixed;
	}

	footer nav ul {
		display: flex;
		justify-content: center;
		align-items: center;
		gap: 2rem;
	}
}

@media screen and (max-width: 799px) {
	:root {
		--content-box-padding: 1rem;
	}

	html, body {
		font-size: 14px;
	}

	section .container {
		width: 100%;
		padding: 0;
		overflow: hidden;
	}

	section .container > * {
		width: 100%;
	}

	section.greeting {
		font-size: 18px;
		letter-spacing: 0.05em;
		line-height: 2;
	}

	section.greeting {
		padding: var(--content-box-padding);
	}

	section.event p {
		padding: 0 var(--content-box-padding);
	}

	section.willget .container {
		padding-bottom: var(--content-box-padding);
	}

	section.willget .btn {
		width: calc(100% - var(--content-box-padding) * 2);
		margin-left: var(--content-box-padding);
		margin-right: var(--content-box-padding);
	}

	section.speaker .container {
		padding-bottom: var(--content-box-padding);
	}

	section.speaker .speaker_list li > div {
		width: calc(100% - var(--content-box-padding) * 2);
		margin: var(--content-box-padding) auto 0 auto;
	}

	section.program p {
		padding: 0 var(--content-box-padding);
	}

	section.program .btn {
		padding: 0 var(--content-box-padding) var(--content-box-padding) var(--content-box-padding);
	}

	section.recommend {
		padding: var(--content-box-padding);
	}

	section.ticket .container {
		padding: 0;
	}

	section.ticket h2 {
		margin-bottom: 0;
	}

	section.ticket .container p {
		margin-bottom: 0;
		padding: var(--content-box-padding);
	}

	section.ticket .btns {
		padding: 0 var(--content-box-padding) var(--content-box-padding) var(--content-box-padding);
		grid-template-columns: 1fr;
		gap: 1rem;
	}

	section.ticket .btns > :nth-child(1) {
		grid-row: 4;
	}
	section.ticket .btns > :nth-child(2) {
		grid-row: 3;
	}
	section.ticket .btns > :nth-child(3) {
		grid-row: 2;
	}

	section.join .container {
		padding: 0;
	}

	section.join .container:nth-child(2) {
		padding-bottom: var(--content-box-padding);
	}

	section.join p,
	section.join .btn {
		padding: 0 var(--content-box-padding);
	}

	section.join .container:last-child p {
		padding-bottom: 1em;
		font-size: 18px;
		letter-spacing: 0.05em;
		line-height: 2;
	}

	section.about {
		padding-bottom: var(--content-box-padding);
	}

	section.about .info {
		font-size: 13px;
	}

	footer nav li::after {
		display: none;
	}
}