:root {
	color-scheme: light dark;
	--font-sans:
		system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
	--font-mono:
		ui-monospace, SFMono-Regular, SFMono-Regular, Menlo, Monaco, Consolas,
		"Liberation Mono", monospace;

	--space-1: 0.25rem;
	--space-2: 0.5rem;
	--space-3: 0.75rem;
	--space-4: 1rem;
	--space-5: 1.5rem;
	--space-6: 2rem;
	--space-7: 3rem;
	--space-8: 4rem;
	--space-9: 6rem;

	--radius-sm: 0.75rem;
	--radius-md: 1rem;
	--radius-lg: 1.5rem;
	--radius-xl: 2rem;
	--radius-pill: 999px;

	--border-width: 1px;
	--content-width: 74rem;
	--content-narrow: 58rem;

	--text-xs: 0.75rem;
	--text-sm: 0.9375rem;
	--text-base: 1rem;
	--text-lg: 1.125rem;
	--text-xl: clamp(1.25rem, 1.1rem + 0.8vw, 1.65rem);
	--text-2xl: clamp(2rem, 1.4rem + 2.4vw, 3.4rem);
	--text-3xl: clamp(2.6rem, 2rem + 3vw, 4.8rem);

	--shadow-soft: 0 20px 60px rgba(37, 99, 235, 0.12);
	--shadow-card: 0 18px 40px rgba(15, 23, 42, 0.08);
	--shadow-strong: 0 30px 80px rgba(15, 23, 42, 0.2);

	--duration-fast: 180ms;
	--duration-base: 260ms;
	--easing-standard: cubic-bezier(0.22, 1, 0.36, 1);

	--color-primary: #2563eb;
	--color-primary-strong: #1d4ed8;
	--color-primary-soft: rgba(37, 99, 235, 0.16);
	--color-accent: #38bdf8;
	--color-bg: #f4f8ff;
	--color-bg-elevated: rgba(255, 255, 255, 0.82);
	--color-bg-strong: rgba(255, 255, 255, 0.96);
	--color-panel: rgba(255, 255, 255, 0.68);
	--color-text: #0f172a;
	--color-text-muted: #475569;
	--color-line: rgba(148, 163, 184, 0.24);
	--color-line-strong: rgba(37, 99, 235, 0.22);
	--color-code: #e8f0ff;
	--color-glow: rgba(56, 189, 248, 0.18);
	--color-white-solid: #ffffff;
	--color-overlay-light-04: rgba(255, 255, 255, 0.04);
	--color-overlay-light-05: rgba(255, 255, 255, 0.05);
	--color-overlay-light-10: rgba(255, 255, 255, 0.1);
	--color-overlay-light-30: rgba(255, 255, 255, 0.3);
	--color-overlay-dark-55: rgba(0, 0, 0, 0.55);
	--color-primary-alpha-12: rgba(37, 99, 235, 0.12);
	--color-primary-alpha-14: rgba(37, 99, 235, 0.14);
	--color-primary-alpha-22: rgba(37, 99, 235, 0.22);
	--color-primary-alpha-28: rgba(37, 99, 235, 0.28);
	--color-primary-alpha-34: rgba(37, 99, 235, 0.34);
	--color-primary-alpha-35: rgba(37, 99, 235, 0.35);
	--color-sky-alpha-14: rgba(56, 189, 248, 0.14);
	--color-sky-alpha-20: rgba(56, 189, 248, 0.2);
	--color-sky-alpha-40: rgba(56, 189, 248, 0.4);
}

@media (prefers-color-scheme: dark) {
	:root {
		--shadow-soft: 0 24px 60px rgba(2, 8, 23, 0.4);
		--shadow-card: 0 18px 50px rgba(2, 8, 23, 0.45);
		--shadow-strong: 0 36px 90px rgba(2, 8, 23, 0.6);

		--color-primary-soft: rgba(37, 99, 235, 0.22);
		--color-bg: #07111f;
		--color-bg-elevated: rgba(9, 18, 34, 0.82);
		--color-bg-strong: rgba(8, 15, 28, 0.94);
		--color-panel: rgba(10, 20, 37, 0.72);
		--color-text: #e2e8f0;
		--color-text-muted: #94a3b8;
		--color-line: rgba(148, 163, 184, 0.16);
		--color-line-strong: rgba(56, 189, 248, 0.24);
		--color-code: rgba(15, 23, 42, 0.96);
		--color-glow: rgba(37, 99, 235, 0.22);
	}
}

* {
	box-sizing: border-box;
}

html {
	scroll-behavior: smooth;
}

body {
	margin: 0;
	min-height: 100vh;
	font-family: var(--font-sans);
	font-size: var(--text-base);
	line-height: 1.65;
	color: var(--color-text);
	background:
		radial-gradient(circle at top left, var(--color-glow), transparent 28rem),
		radial-gradient(
			circle at 85% 12%,
			var(--color-primary-alpha-14),
			transparent 22rem
		),
		linear-gradient(180deg, var(--color-overlay-light-30), transparent 20%),
		var(--color-bg);
	position: relative;
	overflow-x: hidden;
}

body::before,
body::after {
	content: "";
	position: fixed;
	inset: 0;
	pointer-events: none;
	z-index: -1;
}

body::before {
	background-image:
		linear-gradient(
			var(--color-line) var(--border-width),
			transparent var(--border-width)
		),
		linear-gradient(
			90deg,
			var(--color-line) var(--border-width),
			transparent var(--border-width)
		);
	background-size: 8rem 8rem;
	mask-image: linear-gradient(
		180deg,
		var(--color-overlay-dark-55),
		transparent 80%
	);
}

body::after {
	background:
		radial-gradient(
			circle at 15% 25%,
			var(--color-sky-alpha-14),
			transparent 18rem
		),
		radial-gradient(
			circle at 80% 70%,
			var(--color-primary-alpha-12),
			transparent 20rem
		);
	opacity: 0.95;
}

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

button {
	font: inherit;
}

code,
pre {
	font-family: var(--font-mono);
}

.copy-en,
.copy-zh {
	display: inline;
}

body.lang-zh .copy-en,
body.lang-en .copy-zh {
	display: none;
}

.page-shell {
	width: min(calc(100% - var(--space-6)), var(--content-width));
	margin: 0 auto;
	padding: var(--space-5) 0 var(--space-8);
}

.surface {
	border: var(--border-width) solid var(--color-line);
	background: linear-gradient(
		180deg,
		var(--color-bg-elevated),
		var(--color-panel)
	);
	backdrop-filter: blur(18px);
	box-shadow: var(--shadow-card);
}

.surface-hero {
	position: relative;
	overflow: hidden;
}

.surface-hero::before {
	content: "";
	position: absolute;
	inset: auto -12% -40% 34%;
	height: 24rem;
	background: radial-gradient(
		circle,
		var(--color-primary-alpha-22),
		transparent 60%
	);
	pointer-events: none;
}

.site-header {
	position: sticky;
	top: var(--space-4);
	z-index: 20;
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: var(--space-4);
	margin-bottom: var(--space-6);
	padding: var(--space-3) var(--space-4);
	border: var(--border-width) solid var(--color-line);
	border-radius: var(--radius-pill);
	background: var(--color-bg-strong);
	backdrop-filter: blur(18px);
	box-shadow: var(--shadow-soft);
}

.brand {
	display: inline-flex;
	align-items: center;
	gap: var(--space-3);
	min-width: 0;
}

.brand-mark {
	width: 2.5rem;
	height: 2.5rem;
	border-radius: 50%;
	object-fit: contain;
	box-shadow: 0 10px 24px var(--color-primary-alpha-35);
}

.brand-lockup {
	display: flex;
	flex-direction: column;
	gap: 0.1rem;
	min-width: 0;
}

.brand-name {
	font-size: var(--text-sm);
	font-weight: 700;
	letter-spacing: 0.02em;
}

.brand-ascii {
	font-size: var(--text-xs);
	color: var(--color-text-muted);
}

.header-actions {
	display: flex;
	align-items: center;
	gap: var(--space-3);
}

.lang-toggle {
	display: inline-flex;
	align-items: center;
	gap: var(--space-1);
	padding: var(--space-1);
	border-radius: var(--radius-pill);
	border: var(--border-width) solid var(--color-line);
	background: var(--color-panel);
}

.lang-option {
	border: 0;
	padding: var(--space-2) var(--space-4);
	border-radius: var(--radius-pill);
	background: transparent;
	color: var(--color-text-muted);
	cursor: pointer;
	transition:
		background var(--duration-fast) var(--easing-standard),
		color var(--duration-fast) var(--easing-standard),
		transform var(--duration-fast) var(--easing-standard);
}

.lang-option:hover,
.lang-option:focus-visible {
	color: var(--color-text);
	outline: none;
}

.lang-option.is-active {
	color: var(--color-white-solid);
	background: linear-gradient(
		135deg,
		var(--color-primary),
		var(--color-primary-strong)
	);
}

.section {
	margin-bottom: var(--space-8);
}

.hero {
	display: grid;
	grid-template-columns: minmax(0, 1.15fr) minmax(18rem, 0.85fr);
	gap: var(--space-6);
	padding: var(--space-8);
	border-radius: var(--radius-xl);
}

.hero-copy {
	position: relative;
	z-index: 1;
}

.eyebrow {
	display: inline-flex;
	align-items: center;
	gap: var(--space-2);
	margin: 0 0 var(--space-4);
	padding: var(--space-2) var(--space-3);
	border-radius: var(--radius-pill);
	background: var(--color-primary-soft);
	color: var(--color-primary-strong);
	font-size: var(--text-xs);
	font-weight: 700;
	letter-spacing: 0.1em;
	text-transform: uppercase;
}

.hero-title,
.section-heading h2 {
	margin: 0;
	line-height: 1.05;
	letter-spacing: -0.04em;
}

.hero-title {
	max-width: 12ch;
	font-size: var(--text-3xl);
}

.lead {
	margin: var(--space-5) 0 var(--space-3);
	font-size: var(--text-xl);
	color: var(--color-text);
}

.hero-summary,
.section-copy,
.feature-card p,
.feature-list-item p,
.doc-card p,
.install-note,
.step p,
.flow-node p,
.footer-copy {
	color: var(--color-text-muted);
}

.hero-summary {
	max-width: 38rem;
	margin: 0 0 var(--space-5);
}

.hero-actions,
.footer-links {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-3);
}

.button {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: var(--space-2);
	min-height: 3rem;
	padding: 0 var(--space-5);
	border-radius: var(--radius-pill);
	border: var(--border-width) solid transparent;
	font-weight: 700;
	transition:
		transform var(--duration-base) var(--easing-standard),
		border-color var(--duration-base) var(--easing-standard),
		background var(--duration-base) var(--easing-standard),
		color var(--duration-base) var(--easing-standard),
		box-shadow var(--duration-base) var(--easing-standard);
}

.button:hover,
.button:focus-visible,
.doc-link:hover,
.doc-link:focus-visible,
.footer-links a:hover,
.footer-links a:focus-visible {
	transform: translateY(-0.125rem);
	outline: none;
}

.button-primary {
	color: var(--color-white-solid);
	background: linear-gradient(
		135deg,
		var(--color-primary),
		var(--color-primary-strong)
	);
	box-shadow: 0 14px 26px var(--color-primary-alpha-28);
}

.button-primary:hover,
.button-primary:focus-visible {
	box-shadow: 0 18px 34px var(--color-primary-alpha-34);
}

.button-secondary,
.button-ghost {
	border-color: var(--color-line-strong);
	background: var(--color-overlay-light-04);
}

.button-small {
	min-height: 2.5rem;
	padding: 0 var(--space-4);
}

.button-wide {
	width: 100%;
}

.hero-chips,
.flow-legend {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
	margin: var(--space-5) 0 0;
	padding: 0;
	list-style: none;
}

.hero-chips li,
.legend-pill,
.install-pill,
.install-status {
	display: inline-flex;
	align-items: center;
	min-height: 2rem;
	padding: 0 var(--space-3);
	border-radius: var(--radius-pill);
	border: var(--border-width) solid var(--color-line);
	background: var(--color-overlay-light-05);
	font-size: var(--text-xs);
	font-weight: 700;
}

.hero-panel {
	display: grid;
	align-content: center;
	gap: var(--space-4);
}

.hero-card {
	position: relative;
	padding: var(--space-5);
	border-radius: var(--radius-lg);
	border: var(--border-width) solid var(--color-line);
	background:
		linear-gradient(180deg, var(--color-overlay-light-10), transparent),
		var(--color-bg-strong);
	box-shadow: var(--shadow-soft);
	overflow: hidden;
}

.hero-card::after {
	content: "";
	position: absolute;
	inset: auto -10% -45% auto;
	width: 14rem;
	height: 14rem;
	border-radius: 50%;
	background: radial-gradient(
		circle,
		var(--color-sky-alpha-20),
		transparent 60%
	);
}

.hero-card-label,
.install-card-head,
.doc-kicker,
.footer-title,
.node-title,
.feature-card h3,
.feature-list-item h3,
.step h3,
.doc-card h3 {
	margin: 0;
	font-weight: 700;
}

.hero-card-label,
.doc-kicker {
	margin-bottom: var(--space-3);
	font-size: var(--text-xs);
	letter-spacing: 0.12em;
	text-transform: uppercase;
	color: var(--color-text-muted);
}

.hero-route {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
	align-items: center;
	font-size: var(--text-sm);
	font-weight: 700;
}

.hero-terminal {
	display: grid;
	gap: var(--space-2);
	margin-top: var(--space-4);
	padding: var(--space-4);
	border-radius: var(--radius-md);
	background: var(--color-code);
	border: var(--border-width) solid var(--color-line);
}

.terminal-dots {
	display: flex;
	gap: var(--space-2);
}

.terminal-dots span {
	width: 0.625rem;
	height: 0.625rem;
	border-radius: 50%;
	background: var(--color-line-strong);
}

.terminal-line {
	font-family: var(--font-mono);
	font-size: var(--text-xs);
	color: var(--color-text-muted);
}

.hero-ascii {
	margin-bottom: var(--space-3);
	font-family: var(--font-mono);
	font-size: clamp(1.6rem, 1.2rem + 1vw, 2.5rem);
	color: var(--color-accent);
}

.section-heading {
	max-width: var(--content-narrow);
	margin-bottom: var(--space-5);
}

.section-heading h2 {
	font-size: var(--text-2xl);
}

.section-copy {
	margin: var(--space-3) 0 0;
	font-size: var(--text-lg);
}

.feature-grid,
.docs-grid {
	display: grid;
	grid-template-columns: repeat(3, minmax(0, 1fr));
	gap: var(--space-4);
}

.feature-card,
.doc-card,
.install-card,
.site-footer,
.architecture,
.feature-list {
	border-radius: var(--radius-lg);
}

.feature-card,
.doc-card {
	padding: var(--space-5);
}

.feature-icon {
	display: grid;
	place-items: center;
	width: 3rem;
	height: 3rem;
	margin-bottom: var(--space-4);
	border-radius: 50%;
	background: var(--color-primary-soft);
	font-size: 1.4rem;
}

.architecture {
	padding: var(--space-5);
}

.architecture-flow {
	display: grid;
	grid-template-columns: repeat(7, auto);
	gap: var(--space-3);
	align-items: stretch;
	overflow-x: auto;
	padding-bottom: var(--space-2);
}

.flow-node {
	min-width: 13rem;
	padding: var(--space-4);
	border-radius: var(--radius-md);
	border: var(--border-width) solid var(--color-line);
	background: var(--color-bg-strong);
}

.flow-node-user,
.flow-node-session {
	border-color: var(--color-line-strong);
}

.flow-arrow {
	display: grid;
	place-items: center;
	min-width: 2rem;
	color: var(--color-primary);
	font-size: 1.5rem;
}

.quickstart-grid {
	display: grid;
	grid-template-columns: minmax(0, 1fr) minmax(18rem, 24rem);
	gap: var(--space-4);
}

.steps {
	display: grid;
	gap: var(--space-4);
	margin: 0;
	padding: 0;
	list-style: none;
}

.step {
	display: grid;
	grid-template-columns: auto minmax(0, 1fr);
	gap: var(--space-4);
	padding: var(--space-5);
}

.step-index {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	width: 3.25rem;
	height: 3.25rem;
	border-radius: 50%;
	background: linear-gradient(
		135deg,
		var(--color-primary),
		var(--color-accent)
	);
	color: var(--color-white-solid);
	font-family: var(--font-mono);
	font-size: var(--text-sm);
	font-weight: 700;
}

.install-card {
	display: grid;
	gap: var(--space-4);
	align-content: start;
	padding: var(--space-5);
}

.install-card-head {
	display: flex;
	justify-content: space-between;
	gap: var(--space-3);
}

.install-status {
	border-color: var(--color-sky-alpha-40);
	color: var(--color-accent);
}

.code-block {
	margin: 0;
	padding: var(--space-4);
	border-radius: var(--radius-md);
	border: var(--border-width) solid var(--color-line);
	background: var(--color-code);
	overflow-x: auto;
	color: var(--color-text);
}

.feature-list {
	display: grid;
	grid-template-columns: repeat(2, minmax(0, 1fr));
	gap: var(--space-4);
	padding: var(--space-5);
}

.feature-list-item {
	padding: var(--space-4);
	border-radius: var(--radius-md);
	border: var(--border-width) solid var(--color-line);
	background: var(--color-overlay-light-04);
}

.doc-link,
.footer-links a {
	color: var(--color-primary);
	font-weight: 700;
	transition: transform var(--duration-base) var(--easing-standard);
}

.site-footer {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: var(--space-4);
	padding: var(--space-5);
}

@media (max-width: 72rem) {
	.hero,
	.quickstart-grid,
	.feature-grid,
	.docs-grid,
	.feature-list {
		grid-template-columns: 1fr;
	}

	.hero {
		padding: var(--space-6);
	}

	.architecture-flow {
		grid-template-columns: 1fr;
	}

	.flow-arrow {
		transform: rotate(90deg);
		min-height: 2rem;
	}

	.site-footer {
		flex-direction: column;
		align-items: flex-start;
	}
}

@media (max-width: 44rem) {
	.page-shell {
		width: min(calc(100% - var(--space-4)), var(--content-width));
		padding-top: var(--space-4);
	}

	.site-header,
	.header-actions,
	.step {
		flex-direction: column;
	}

	.site-header,
	.header-actions {
		align-items: stretch;
	}

	.site-header {
		border-radius: var(--radius-lg);
	}

	.lang-toggle {
		justify-content: space-between;
	}

	.lang-option {
		flex: 1 1 0;
	}

	.hero,
	.architecture,
	.install-card,
	.feature-list,
	.site-footer,
	.feature-card,
	.doc-card,
	.step {
		padding: var(--space-4);
	}

	.hero-title {
		max-width: none;
	}

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

@media (prefers-reduced-motion: reduce) {
	html {
		scroll-behavior: auto;
	}

	*,
	*::before,
	*::after {
		animation-duration: 0.01ms;
		animation-iteration-count: 1;
		transition-duration: 0.01ms;
		scroll-behavior: auto;
	}
}