:root {
	--bg: #fff;
	--surface: #f7f7f5;
	--text: #242424;
	--muted: #6b6b6b;
	--line: #e6e6e3;
	--accent: #17684d;
	--content: 1080px;
	--article: 720px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
	margin: 0; background: var(--bg); color: var(--text);
	font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
	font-size: 16px; line-height: 1.9; -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: .2em; }
a:hover { opacity: .72; }
img { max-width: 100%; height: auto; }
#with-header {
	display: flex; align-items: center; justify-content: space-between; gap: 32px;
	max-width: var(--content); min-height: 76px; margin: 0 auto; padding: 16px 24px;
}
.site-logo {
	flex: 0 0 auto; color: var(--text); font-size: 22px; font-weight: 700;
	line-height: 1; letter-spacing: .02em; text-decoration: none;
}
#with-header h1 {
	margin: 0; color: var(--muted); font-size: 13px; font-weight: 400;
	line-height: 1.5; text-align: right;
}
.mainnavi { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.mainnavi ul {
	display: flex; gap: 28px; max-width: var(--content); margin: 0 auto;
	padding: 0 24px; list-style: none;
}
.mainnavi a {
	display: block; padding: 12px 0; color: var(--muted);
	font-size: 14px; font-weight: 600; text-decoration: none;
}
.mainnavi a:hover { color: var(--text); opacity: 1; }
#contents {
	display: grid; grid-template-columns: minmax(0, var(--article)) 280px;
	gap: 72px; max-width: var(--content); margin: 0 auto; padding: 56px 24px 80px;
}
#seomain { min-width: 0; }
#seomain > :first-child { margin-top: 0; }
h2, .maintitle {
	margin: 2.8em 0 .9em; padding: 0 0 .55em; border-bottom: 1px solid var(--line);
	color: var(--text); font-size: clamp(22px, 3vw, 29px); font-weight: 700;
	line-height: 1.5; letter-spacing: .01em;
}
h3 { margin: 2.2em 0 .7em; color: var(--text); font-size: 20px; line-height: 1.55; }
h4, h5, h6 { margin: 1.8em 0 .5em; line-height: 1.6; }
p { margin: 0 0 1.5em; }
#seomain ul, #seomain ol { margin: 1.2em 0 1.8em; padding-left: 1.7em; }
#seomain li { margin: .45em 0; }
.whatsnew { padding: 0 !important; border-top: 1px solid var(--line); list-style: none; }
.whatsnew li { margin: 0 !important; padding: 13px 4px; border-bottom: 1px solid var(--line); }
.whatsnew a { display: block; color: var(--text); text-decoration: none; }
.whatsnew a:hover { color: var(--accent); opacity: 1; }
.expli, .b-back, .nb, .comnt {
	margin: 1.5em 0; padding: 18px 20px; border-radius: 8px; background: var(--surface);
}
.exp { font-weight: 600; }
.main-img { display: block; margin: 28px auto; border-radius: 8px; }
table { width: 100%; margin: 24px 0; border-collapse: collapse; font-size: 14px; }
th, td {
	padding: 10px 12px; border: 1px solid var(--line); color: var(--text);
	text-align: left; vertical-align: top;
}
th { background: var(--surface); }
.boxcontent {
	position: sticky; top: 24px; align-self: start;
	padding-left: 24px; border-left: 1px solid var(--line);
}
.sectiontitle, .boxcontent .sectiontitle {
	margin: 0 0 10px !important; padding: 0; border: 0; font-size: 15px; font-weight: 700;
}
.boxcontent .sectiontitle:not(:first-child) { margin-top: 30px !important; }
.sidebar-stories { margin: 0 0 26px; padding: 0; list-style: none; }
.sidebar-stories li { margin: 0; border-bottom: 1px solid var(--line); }
.sidebar-stories a {
	display: block; padding: 9px 0; color: var(--muted);
	font-size: 13px; line-height: 1.55; text-decoration: none;
}
.sidebar-stories a:hover { color: var(--text); opacity: 1; }
#footer {
	padding: 30px 24px; border-top: 1px solid var(--line);
	color: var(--muted); font-size: 12px; text-align: center;
}
#footer a { color: inherit; }
#footer hr, br.clear { display: none; }
.center { text-align: center; }
.red { color: #b42318; }
.black { color: var(--text); }
.strong { font-weight: 700; }
.m-t-20 { margin-top: 2.8em !important; }
.sp { display: none; }
@media (max-width: 820px) {
	#with-header { display: block; min-height: 0; padding: 20px; }
	#with-header h1 { margin-top: 9px; font-size: 12px; text-align: left; }
	.mainnavi ul { gap: 20px; padding: 0 20px; overflow-x: auto; white-space: nowrap; }
	#contents { display: block; padding: 36px 20px 60px; }
	.boxcontent {
		position: static; margin-top: 56px; padding: 28px 0 0;
		border-top: 1px solid var(--line); border-left: 0;
	}
	table { display: block; overflow-x: auto; white-space: nowrap; }
	.pc { display: none !important; }
	.sp { display: initial; }
}
@media (max-width: 480px) {
	body { font-size: 15px; line-height: 1.85; }
	h2, .maintitle { font-size: 22px; }
	.expli, .b-back, .nb, .comnt { padding: 15px; }
}