/* SEO 专题：独立整页（深色，对齐品牌；不是首页弹层） */

:root {
	--seo-bg: #12151a;
	--seo-panel: #1b1f22;
	--seo-text: #ffffff;
	--seo-muted: rgba(255, 255, 255, 0.72);
	--seo-line: rgba(255, 255, 255, 0.18);
	--seo-accent: #2b4a8c;
}

* { box-sizing: border-box; }

html, body {
	margin: 0;
	min-height: 100%;
	background: var(--seo-bg);
	color: var(--seo-text);
	font-family: "Source Sans Pro", "PingFang SC", "Microsoft YaHei", Helvetica, sans-serif;
	line-height: 1.7;
	letter-spacing: 0.04rem;
}

a {
	color: #fff;
	text-decoration: underline;
	text-underline-offset: 0.18em;
}

a:hover { opacity: 0.85; }

.seo-top {
	display: flex;
	flex-wrap: wrap;
	gap: 0.75rem 1.25rem;
	align-items: center;
	justify-content: space-between;
	padding: 1rem 1.25rem;
	border-bottom: 1px solid var(--seo-line);
	background: rgba(0, 0, 0, 0.35);
}

.seo-top a {
	text-decoration: none;
	border: 0;
	font-size: 0.9rem;
	letter-spacing: 0.1rem;
}

.seo-top-nav {
	display: flex;
	flex-wrap: wrap;
	gap: 0.75rem 1.1rem;
}

.seo-shell {
	max-width: 46rem;
	margin: 0 auto;
	padding: 2rem 1.25rem 3.5rem;
}

.seo-badge {
	display: inline-block;
	margin: 0 0 0.9rem;
	padding: 0.35rem 0.75rem;
	font-size: 0.75rem;
	letter-spacing: 0.14rem;
	border: 1px solid rgba(255, 255, 255, 0.55);
}

.seo-shell h1 {
	margin: 0 0 0.85rem;
	font-size: clamp(1.8rem, 4vw, 2.4rem);
	line-height: 1.25;
	letter-spacing: 0.16rem;
	font-weight: 700;
}

.seo-lead {
	margin: 0 0 1.5rem;
	color: rgba(255, 255, 255, 0.9);
	font-size: 1.02rem;
}

.seo-note {
	margin: 0 0 1.5rem;
	padding: 1rem 1.1rem;
	border-left: 3px solid rgba(255, 255, 255, 0.65);
	background: rgba(255, 255, 255, 0.06);
}

.seo-shell h2 {
	margin: 1.75rem 0 0.75rem;
	font-size: 1.15rem;
	letter-spacing: 0.12rem;
	font-weight: 700;
}

.seo-shell ul, .seo-shell ol {
	margin: 0 0 1rem 1.2rem;
	padding: 0;
}

.seo-shell li { margin: 0 0 0.45rem; }

.seo-grid {
	display: grid;
	grid-template-columns: 1fr 1fr;
	gap: 0.75rem;
	margin: 0 0 1rem;
	padding: 0;
	list-style: none;
}

.seo-grid li {
	margin: 0;
	padding: 0.9rem;
	background: rgba(255, 255, 255, 0.05);
	border: 1px solid var(--seo-line);
}

.seo-grid strong {
	display: block;
	margin: 0 0 0.3rem;
}

.seo-grid span {
	display: block;
	color: var(--seo-muted);
	font-size: 0.9rem;
}

.seo-actions {
	display: flex;
	flex-wrap: wrap;
	gap: 0.75rem;
	margin: 1.75rem 0 1.5rem;
}

.seo-actions a {
	display: inline-block;
	text-decoration: none;
	border: 1px solid #fff;
	padding: 0.7rem 1.2rem;
	letter-spacing: 0.1rem;
	font-size: 0.9rem;
}

.seo-actions a.primary {
	background: var(--seo-accent);
	border-color: var(--seo-accent);
}

.seo-related {
	margin-top: 1.5rem;
	padding-top: 1rem;
	border-top: 1px solid var(--seo-line);
	font-size: 0.9rem;
}

.seo-related ul {
	margin-top: 0.5rem;
}

.seo-foot {
	margin-top: 2.5rem;
	padding-top: 1rem;
	border-top: 1px solid var(--seo-line);
	font-size: 0.72rem;
	letter-spacing: 0.1rem;
	color: var(--seo-muted);
	text-align: center;
}

@media (max-width: 700px) {
	.seo-grid { grid-template-columns: 1fr; }
}