:root {
	--bg: #f5f6f8;
	--surface: #ffffff;
	--surface-soft: #eef1f5;
	--text: #1f2933;
	--text-light: #52606d;
	--border: #d9e2ec;
	--primary: #2f4f66;
	--primary-hover: #274457;
	--max-width: 1080px;
}

* {
	box-sizing: border-box;
}

html {
	scroll-behavior: smooth;
}

body {
	margin: 0;
	font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
	background: linear-gradient(180deg, #f7f8fa 0%, #f1f3f6 100%);
	color: var(--text);
	line-height: 1.65;
}

a {
	color: inherit;
	text-decoration: none;
}

.container {
	width: min(100% - 2rem, var(--max-width));
	margin: 0 auto;
}

.narrow {
	max-width: 820px;
}

.site-header {
	position: sticky;
	top: 0;
	z-index: 10;
	background: rgba(255, 255, 255, 0.95);
	border-bottom: 1px solid var(--border);
	backdrop-filter: blur(6px);
}

.nav-wrap {
	display: flex;
	align-items: center;
	justify-content: space-between;
	min-height: 64px;
}

.brand {
	font-size: 1.1rem;
	font-weight: 700;
	letter-spacing: 0.02em;
}

.site-nav {
	display: flex;
	gap: 1rem;
	flex-wrap: wrap;
}

.site-nav a {
	color: var(--text-light);
	font-size: 0.95rem;
}

.site-nav a:hover {
	color: var(--text);
}

.section {
	padding: 4rem 0;
}

.section-soft {
	background: var(--surface-soft);
	border-top: 1px solid var(--border);
	border-bottom: 1px solid var(--border);
}

.hero {
	padding: 6rem 0 5rem;
}

.hero h1 {
	margin: 0;
	font-size: clamp(2rem, 4vw, 3rem);
	line-height: 1.2;
}

.hero-subtitle {
	margin-top: 1rem;
	max-width: 760px;
	color: var(--text-light);
	font-size: 1.05rem;
}

.hero-actions {
	margin-top: 1.75rem;
	display: flex;
	gap: 0.75rem;
	flex-wrap: wrap;
}

.btn {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	padding: 0.65rem 1.1rem;
	border-radius: 8px;
	border: 1px solid transparent;
	font-size: 0.95rem;
	font-weight: 600;
}

.btn-primary {
	background: var(--primary);
	color: #fff;
}

.btn-primary:hover {
	background: var(--primary-hover);
}

.btn-secondary {
	background: #fff;
	color: var(--text);
	border-color: var(--border);
}

h2 {
	margin: 0 0 0.85rem;
	font-size: 1.6rem;
}

h3 {
	margin-top: 0;
	margin-bottom: 0.65rem;
	font-size: 1.1rem;
}

p {
	margin-top: 0;
	margin-bottom: 0.9rem;
	color: var(--text-light);
}

.cards {
	margin-top: 1.25rem;
	display: grid;
	grid-template-columns: repeat(2, minmax(0, 1fr));
	gap: 1rem;
}

.card {
	background: var(--surface);
	border: 1px solid var(--border);
	border-radius: 12px;
	padding: 1rem;
}

.contact-note {
	font-size: 0.92rem;
}

.site-footer {
	background: #fff;
	border-top: 1px solid var(--border);
	padding: 1.75rem 0;
}

.footer-wrap {
	display: grid;
	gap: 0.35rem;
}

.footer-links {
	display: flex;
	gap: 1rem;
	margin-bottom: 0.2rem;
}

.footer-links a {
	color: var(--text);
}

.footer-links a:hover {
	text-decoration: underline;
}

.copyright {
	margin-top: 0.35rem;
}

.doc-main {
	padding-bottom: 3rem;
}

.doc-title {
	margin: 0;
	font-size: clamp(1.9rem, 3.5vw, 2.5rem);
}

.doc-meta {
	margin-top: 0.8rem;
	font-size: 0.95rem;
}

.doc-section h2 {
	margin-top: 2rem;
}

.doc-section h2:first-child {
	margin-top: 0;
}

.doc-back {
	margin-top: 1.2rem;
}

.doc-back a {
	display: inline-block;
	padding: 0.45rem 0.8rem;
	border: 1px solid var(--border);
	border-radius: 8px;
	background: #fff;
	color: var(--text);
}

.doc-back a:hover {
	border-color: #bcccdc;
}

@media (max-width: 780px) {
	.nav-wrap {
		flex-direction: column;
		align-items: flex-start;
		padding: 0.7rem 0;
		gap: 0.45rem;
	}

	.section {
		padding: 3rem 0;
	}

	.hero {
		padding-top: 4rem;
	}

	.cards {
		grid-template-columns: 1fr;
	}
}