/* Seven Billion Tokens article — visual skin aligned with /agentic.html. */

:root {
	--sbt-control: #22d3ee;
	--sbt-control-glow: rgba(34, 211, 238, 0.12);
	--sbt-sdr: #f59e0b;
	--sbt-sdr-glow: rgba(245, 158, 11, 0.12);
	--sbt-edge: #a78bfa;
	--sbt-edge-glow: rgba(167, 139, 250, 0.12);
	--sbt-safe: #22c55e;
	--sbt-danger: #f87171;
}

html {
	scroll-behavior: smooth;
}

/* Page Shell */
.blog-article {
	max-width: none;
	margin: 0;
	padding: calc(var(--gn-h, 36px) + var(--nav-h, 64px) + 28px) 0 96px;
	overflow: hidden;
}

.blog-breadcrumb,
.article-language,
.blog-content > .lede,
.blog-content > .claim-box,
.blog-footer {
	box-sizing: border-box;
	max-width: 1120px;
	margin-inline: auto;
	padding-inline: 2rem;
}

.blog-breadcrumb {
	margin-bottom: 0.75rem;
	font-size: 0.82rem;
}

.article-language {
	text-align: right;
	margin-bottom: 0.5rem;
}
.article-language a {
	display: inline-flex;
	align-items: center;
	gap: 0.4rem;
	border: 1px solid var(--border);
	border-radius: 999px;
	padding: 6px 14px;
	color: var(--text-secondary);
	font-size: 0.8rem;
	text-decoration: none;
}
.article-language a:hover {
	border-color: var(--border-hover);
	color: var(--accent);
}

/* Hero */
.blog-header {
	position: relative;
	box-sizing: border-box;
	max-width: none;
	margin: 0;
	padding: 4.75rem 2rem 4.25rem;
	overflow: hidden;
	text-align: center;
}
.blog-header::before {
	position: absolute;
	inset: -48% -25% auto;
	height: 125%;
	background: radial-gradient(circle at 50% 0%, var(--sbt-control-glow), transparent 58%);
	content: "";
	pointer-events: none;
}
.blog-header > * {
	position: relative;
	z-index: 1;
}
.blog-cat-badge {
	display: inline-flex;
	align-items: center;
	gap: 0.45rem;
	margin-bottom: 1rem;
}
.blog-header h1 {
	max-width: 980px;
	margin: 1rem auto;
	font-size: clamp(2.6rem, 7vw, 5rem);
	line-height: 1.02;
	letter-spacing: -0.055em;
}
.blog-subtitle {
	max-width: 760px;
	margin-inline: auto;
	font-size: 1.08rem;
	line-height: 1.8;
}
.blog-meta,
.blog-tags {
	justify-content: center;
}
.blog-tags li a {
	background: var(--bg-card);
	font-family: var(--font-mono);
}

/* Anchor Rail */
.blog-toc {
	position: sticky;
	top: var(--global-nav-height, var(--gn-h, 44px));
	z-index: 20;
	display: flex;
	align-items: center;
	gap: 0.75rem;
	max-width: none;
	margin: 0;
	padding: 0.75rem 2rem;
	overflow-x: auto;
	border-width: 1px 0;
	border-radius: 0;
	background: rgba(5, 8, 13, 0.94);
	backdrop-filter: blur(16px);
}
.blog-toc-title,
.blog-toc-vol {
	flex: 0 0 auto;
	margin: 0;
	padding: 0;
	border: 0;
	font-family: var(--font-mono);
	font-size: 0.72rem;
	font-weight: 700;
	letter-spacing: 0.1em;
	text-transform: uppercase;
	white-space: nowrap;
}
.blog-toc-title {
	color: var(--text-muted);
}
.blog-toc-vol {
	color: var(--accent);
}
.blog-toc ol {
	display: flex;
	flex: 0 0 auto;
	gap: 0.5rem;
	margin: 0;
	padding: 0;
	list-style: none;
}
.blog-toc li {
	margin: 0;
}
.blog-toc li.toc-h3 {
	display: none;
}
.blog-toc a {
	display: block;
	border: 1px solid transparent;
	border-radius: 999px;
	padding: 0.4rem 0.75rem;
	color: var(--text-secondary);
	font-family: var(--font-mono);
	font-size: 0.72rem;
	white-space: nowrap;
	text-decoration: none;
}
.blog-toc a:hover,
.blog-toc a:focus-visible {
	border-color: var(--accent);
	color: var(--accent);
}

/* Article Sections */
.blog-content {
	max-width: none;
	font-size: 1.02rem;
	line-height: 1.85;
}
.blog-content > .lede {
	max-width: 980px;
	margin: 4rem auto 1.25rem;
	color: var(--text-primary);
	font-size: clamp(1.08rem, 2vw, 1.35rem);
	line-height: 1.75;
	text-align: center;
}
.volume {
	margin: 5rem 0 0;
}
.volume-head {
	box-sizing: border-box;
	max-width: 900px;
	margin: 0 auto;
	padding: 0 2rem 2.75rem;
	text-align: center;
}
.volume-head .volume-num {
	display: block;
	margin-bottom: 0.75rem;
	color: var(--accent);
	font-family: var(--font-mono);
	font-size: 0.75rem;
	font-weight: 700;
	letter-spacing: 0.14em;
	text-transform: uppercase;
}
.volume-head h2 {
	margin: 0;
	font-size: clamp(1.8rem, 4vw, 2.6rem);
	letter-spacing: -0.03em;
}
.volume-head .volume-gloss {
	max-width: 760px;
	margin: 0.85rem auto 0;
	color: var(--text-secondary);
	font-size: 0.98rem;
	line-height: 1.75;
}
.volume[data-volume="gewu"] .volume-head .volume-num {
	color: var(--sbt-sdr);
}
.volume[data-volume="zhizhi"] .volume-head .volume-num {
	color: var(--sbt-control);
}
.volume[data-volume="zhixing"] .volume-head .volume-num {
	color: var(--sbt-edge);
}
.blog-content section {
	box-sizing: border-box;
	max-width: 1120px;
	margin: 0 auto;
	padding: 5rem 2rem;
}
.blog-content .volume > section:nth-of-type(even),
.blog-content > section:nth-of-type(even) {
	background: var(--bg-secondary);
	box-shadow: 0 0 0 100vmax var(--bg-secondary);
	clip-path: inset(0 -100vmax);
}
.blog-content h2 {
	max-width: 860px;
	margin: 0 auto 1rem;
	padding: 0;
	font-size: clamp(1.8rem, 4vw, 2.55rem);
	line-height: 1.15;
	letter-spacing: -0.035em;
	text-align: center;
}
.blog-content h2::before {
	display: none;
}
.blog-content section > h3,
.blog-content section > p,
.blog-content section > ul,
.blog-content section > ol:not(.steps),
.blog-content section > .claim-box,
.blog-content section > .prov,
.blog-content section > .term-block,
.blog-content section > blockquote {
	max-width: 820px;
	margin-inline: auto;
}
.blog-content section > ul,
.blog-content section > ol:not(.steps) {
	padding-left: 2rem;
}
.blog-content section > .ledger-scroll,
.blog-content section > .stat-row,
.blog-content section > .ladder-pair,
.blog-content section > .steps {
	max-width: 1120px;
	margin-inline: auto;
}

/* Evidence Blocks */
.claim-box {
	border: 1px solid var(--border);
	border-left: 3px solid var(--accent);
	border-radius: 0 1rem 1rem 0;
	padding: 1.15rem 1.25rem;
	margin: 1.6rem 0;
	background: var(--bg-card);
}
.claim-label {
	display: inline-block;
	margin-bottom: 0.45rem;
	font-family: var(--font-mono);
	font-size: 0.72rem;
	font-weight: 700;
	letter-spacing: 0.08em;
	text-transform: uppercase;
}
.claim-box[data-claim-type="fact"] {
	border-left-color: var(--sbt-safe);
}
.claim-box[data-claim-type="fact"] .claim-label {
	color: var(--sbt-safe);
}
.claim-box[data-claim-type="inference"] {
	border-left-color: var(--sbt-control);
}
.claim-box[data-claim-type="inference"] .claim-label {
	color: var(--sbt-control);
}
.claim-box[data-claim-type="analogy"] {
	border-left-color: var(--sbt-sdr);
}
.claim-box[data-claim-type="analogy"] .claim-label {
	color: var(--sbt-sdr);
}
.claim-box[data-claim-type="thesis"] {
	border-left-color: var(--sbt-edge);
}
.claim-box[data-claim-type="thesis"] .claim-label {
	color: var(--sbt-edge);
}
.prov {
	border-left: 3px solid var(--border);
	border-radius: 0 0.75rem 0.75rem 0;
	padding: 0.85rem 1rem;
	margin: 0.9rem 0 1.75rem;
	background: rgba(255, 255, 255, 0.015);
	color: var(--text-secondary);
	font-family: var(--font-mono);
	font-size: 0.74rem;
	line-height: 1.7;
}
.prov b {
	color: var(--text-primary);
	font-weight: 600;
}

/* Tables and Metrics */
.ledger-scroll {
	overflow-x: auto;
	border: 1px solid var(--border);
	border-radius: 1rem;
	background: rgba(255, 255, 255, 0.015);
	-webkit-overflow-scrolling: touch;
}
.ledger-table {
	min-width: 860px;
	width: 100%;
	margin: 0;
	border-collapse: collapse;
	font-size: 0.84rem;
}
.repo-scale-table {
	min-width: 1080px;
}
.ledger-table th,
.ledger-table td {
	border: 0;
	border-bottom: 1px solid var(--border);
	padding: 0.85rem 1rem;
	text-align: left;
	vertical-align: top;
}
.ledger-table th {
	background: var(--bg-card);
	color: var(--accent);
	font-family: var(--font-mono);
	font-size: 0.72rem;
	letter-spacing: 0.04em;
	text-transform: uppercase;
}
.ledger-table td {
	color: var(--text-secondary);
	line-height: 1.55;
}
.ledger-table td.num,
.ledger-table td.tool {
	font-family: var(--font-mono);
	white-space: nowrap;
}
.ledger-table td.num {
	text-align: right;
}
.ledger-table tr.total td {
	background: rgba(34, 211, 238, 0.04);
	font-weight: 700;
}
.ledger-table tr:last-child td {
	border-bottom: 0;
}
.ledger-table caption {
	caption-side: bottom;
	padding: 0.75rem 1rem 1rem;
	color: var(--text-secondary);
	font-size: 0.78rem;
	line-height: 1.6;
	text-align: left;
}
.stat-row {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
	gap: 1.25rem;
	margin: 2rem 0;
}
.stat-tile {
	border: 1px solid var(--border);
	border-top: 3px solid var(--sbt-control);
	border-radius: 1rem;
	padding: 1.25rem 1.35rem;
	background: var(--bg-card);
}
.stat-tile:nth-child(2) {
	border-top-color: var(--sbt-sdr);
}
.stat-tile:nth-child(3) {
	border-top-color: var(--sbt-edge);
}
.stat-num {
	display: block;
	color: var(--accent);
	font-family: var(--font-mono);
	font-size: clamp(1.45rem, 3vw, 2rem);
	font-weight: 700;
	line-height: 1.2;
}
.stat-cap {
	display: block;
	margin-top: 0.45rem;
	color: var(--text-secondary);
	font-size: 0.82rem;
	line-height: 1.55;
}

/* Terminal and Utility Components */
.term-block {
	margin: 1.75rem 0;
	border: 1px solid var(--border);
	border-radius: 1rem;
	overflow: hidden;
	background: #06090d;
}
.term-head {
	padding: 0.55rem 0.85rem;
	border-bottom: 1px solid var(--border);
	color: var(--text-secondary);
	font-family: var(--font-mono);
	font-size: 0.7rem;
	letter-spacing: 0.08em;
	text-transform: uppercase;
}
.term-block pre {
	margin: 0;
	padding: 1rem;
	overflow-x: auto;
	font-family: var(--font-mono);
	font-size: 0.8rem;
	line-height: 1.55;
}
.exit {
	color: var(--sbt-safe);
}
.block-line,
del.stale {
	color: var(--sbt-danger);
}
del.stale {
	font-family: var(--font-mono);
	text-decoration: line-through;
	text-decoration-thickness: 1px;
	white-space: nowrap;
}
.stale-pair {
	font-family: var(--font-mono);
	font-size: 0.86rem;
	white-space: nowrap;
}
.stale-pair .arrow {
	margin: 0 0.35rem;
	color: var(--text-secondary);
}

/* Ladders and Playbook */
.ladder-pair {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
	gap: 1.25rem;
	margin: 2rem 0;
}
.ladder {
	border: 1px solid var(--border);
	border-radius: 1rem;
	padding: 1.35rem;
	background: var(--bg-card);
}
.ladder--product {
	border-top: 3px solid var(--sbt-safe);
}
.ladder--process {
	border-top: 3px solid var(--sbt-control);
}
.ladder h4 {
	margin: 0 0 0.6rem;
}
.ladder ol {
	margin: 0;
	padding-left: 1.2rem;
	font-size: 0.85rem;
	line-height: 1.85;
}
.ladder-note {
	grid-column: 1 / -1;
	border-left: 3px solid var(--sbt-edge);
	border-radius: 0 0.75rem 0.75rem 0;
	padding: 1rem 1.15rem;
	background: var(--sbt-edge-glow);
	color: var(--text-secondary);
}
.steps {
	counter-reset: step;
	display: grid;
	grid-template-columns: repeat(2, minmax(0, 1fr));
	gap: 1.25rem;
	margin: 2rem 0;
	padding: 0;
	list-style: none;
}
.steps li {
	counter-increment: step;
	position: relative;
	min-height: 100%;
	margin: 0;
	padding: 1.35rem 1.35rem 1.35rem 4rem;
	border: 1px solid var(--border);
	border-top: 3px solid var(--sbt-control);
	border-radius: 1rem;
	background: var(--bg-card);
}
.steps li::before {
	position: absolute;
	top: 1.25rem;
	left: 1.25rem;
	display: grid;
	place-items: center;
	width: 2rem;
	height: 2rem;
	border: 1px solid var(--accent);
	border-radius: 0.55rem;
	background: var(--accent-glow);
	color: var(--accent);
	content: counter(step);
	font-family: var(--font-mono);
	font-weight: 700;
}
.steps h4 {
	margin: 0 0 0.45rem;
	font-size: 1rem;
}
.steps p {
	margin: 0;
	color: var(--text-secondary);
	font-size: 0.9rem;
	line-height: 1.65;
}

/* Footer */
.blog-footer {
	box-sizing: border-box;
	margin-top: 4rem;
}
.blog-author,
.blog-related li a {
	border-radius: 1rem;
	background: var(--bg-card);
}

/* Chinese typography */
html:lang(zh-CN) .blog-article,
html:lang(zh-CN) .blog-header,
html:lang(zh-CN) .blog-breadcrumb,
html:lang(zh-CN) .blog-toc,
html:lang(zh-CN) .blog-content,
html:lang(zh-CN) .blog-footer {
	font-family:
		"PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Source Han Sans SC",
		"Microsoft YaHei", var(--font-sans), sans-serif;
}
html:lang(zh-CN) .blog-content {
	line-height: 2;
	letter-spacing: 0.01em;
}
html:lang(zh-CN) .blog-content code,
html:lang(zh-CN) .blog-content pre,
html:lang(zh-CN) .term-block,
html:lang(zh-CN) .ledger-table td.num,
html:lang(zh-CN) .ledger-table td.tool,
html:lang(zh-CN) .stat-num,
html:lang(zh-CN) .prov {
	font-family: var(--font-mono);
}

section[id],
h1[id],
h2[id],
h3[id],
.volume-head {
	scroll-margin-top: calc(var(--gn-h, 36px) + 72px);
}

@media (max-width: 900px) {
	.blog-header {
		padding: 3.5rem 1.25rem 3.25rem;
	}
	.blog-content section {
		padding: 4rem 1.25rem;
	}
	.steps {
		grid-template-columns: 1fr;
	}
}

@media (max-width: 640px) {
	.blog-article {
		padding-top: calc(var(--gn-h, 36px) + var(--nav-h, 64px) + 18px);
	}
	.blog-breadcrumb,
	.article-language,
	.blog-content > .lede,
	.blog-content > .claim-box,
	.blog-footer,
	.volume-head {
		padding-inline: 1.25rem;
	}
	.blog-header h1 {
		font-size: 2.35rem;
	}
	.blog-toc {
		padding-inline: 1.25rem;
	}
	.ledger-table {
		font-size: 0.78rem;
	}
	.ledger-table th,
	.ledger-table td {
		padding: 0.55rem 0.65rem;
	}
	.volume {
		margin-top: 3.75rem;
	}
	.steps li {
		padding: 1.2rem 1.2rem 1.2rem 3.75rem;
	}
}