/* p-rick — the working-paper journal
   Identity: scholarly ink on paper, editorial crimson, hairline rules.
   Type: Fraunces (display serif) · Inter (UI) · IBM Plex Mono (numbers).
   Themes via [data-theme] on <html>; set by assets/theme.js, no-flash inline. */

:root {
  --serif: 'Fraunces', Georgia, 'Times New Roman', serif;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  --step--1: clamp(0.78rem, 0.74rem + 0.2vw, 0.84rem);
  --step-0: clamp(0.95rem, 0.9rem + 0.25vw, 1.02rem);
  --step-1: clamp(1.15rem, 1.05rem + 0.5vw, 1.3rem);
  --step-2: clamp(1.45rem, 1.25rem + 1vw, 1.75rem);
  --step-3: clamp(1.8rem, 1.4rem + 2vw, 2.4rem);
  --step-4: clamp(2.3rem, 1.6rem + 3.4vw, 3.6rem);

  --measure: 66ch;
  --gutter: clamp(1.2rem, 4vw, 3.5rem);
  --maxw: 1180px;
  --rule-w: 1px;
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #fbfaf6;
  --bg-raise: #ffffff;
  --bg-soft: #f3f1ea;
  --bg-ink: #1a1b20;
  --ink: #1a1b20;
  --text: #31343c;
  --muted: #5e626c;
  --faint: #767a81;
  --accent: #a13526;
  --accent-deep: #7f291c;
  --accent-soft: rgba(161, 53, 38, 0.07);
  --rule: rgba(26, 27, 32, 0.14);
  --rule-strong: rgba(26, 27, 32, 0.6);
  --card: #ffffff;
  --card-border: rgba(26, 27, 32, 0.1);
  --shadow: 0 1px 2px rgba(26, 27, 32, 0.04), 0 14px 34px rgba(26, 27, 32, 0.07);
  --selection: rgba(161, 53, 38, 0.2);
  --hero-ink: #14151a;
  --fig-bg: #ffffff;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #15161a;
  --bg-raise: #1c1e24;
  --bg-soft: #101114;
  --bg-ink: #f5f2ea;
  --ink: #f5f2ea;
  --text: #dcd8cd;
  --muted: #9a968b;
  --faint: #767369;
  --accent: #e2604e;
  --accent-deep: #e77a68;
  --accent-soft: rgba(226, 96, 78, 0.09);
  --rule: rgba(245, 242, 234, 0.15);
  --rule-strong: rgba(245, 242, 234, 0.62);
  --card: #1c1e24;
  --card-border: rgba(245, 242, 234, 0.11);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 16px 40px rgba(0, 0, 0, 0.45);
  --selection: rgba(226, 96, 78, 0.28);
  --hero-ink: #f5f2ea;
  --fig-bg: #1a1c21;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

html { scroll-padding-top: 5.5rem; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: var(--step-0);
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color 0.35s ease, color 0.35s ease;
}

::selection { background: var(--selection); }

a { color: var(--ink); text-decoration: none; }
a:hover { color: var(--accent); }
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

img { max-width: 100%; height: auto; }

/* ---------- skip link ---------- */
.skip {
  position: absolute; left: -999px; top: 0;
  background: var(--bg-ink); color: var(--bg);
  padding: 0.6rem 1rem; z-index: 200;
  font-family: var(--mono); font-size: 0.8rem;
}
.skip:focus { left: 0; color: var(--bg); }

/* ---------- masthead ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg);
  border-bottom: var(--rule-w) solid var(--rule);
  transition: border-color 0.35s ease;
}
.masthead {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.85rem var(--gutter) 0.8rem;
  display: flex; align-items: baseline; gap: 2rem;
}
.brand { display: flex; align-items: baseline; gap: 0.55rem; }
.brand-mark {
  font-family: var(--serif);
  font-weight: 640;
  font-size: 1.5rem;
  letter-spacing: -0.015em;
  color: var(--ink);
  font-variation-settings: "SOFT" 0, "WONK" 0;
  transition: color 0.2s ease;
}
.brand:hover .brand-mark { color: var(--accent); }
.brand-sub {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: lowercase;
}
.masthead nav {
  margin-left: auto;
  display: flex; gap: 1.6rem;
  font-size: var(--step--1);
  font-weight: 500;
}
.masthead nav a {
  color: var(--muted);
  padding: 0.2rem 0;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.masthead nav a:hover { color: var(--ink); border-bottom-color: var(--accent); }
.masthead nav a[aria-current] { color: var(--accent); border-bottom-color: var(--accent); }

.theme-toggle {
  background: none; border: 1px solid var(--rule);
  color: var(--muted); cursor: pointer;
  width: 2rem; height: 2rem;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 999px;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
  touch-action: manipulation;
}
.theme-toggle:hover { color: var(--ink); border-color: var(--rule-strong); }
.theme-toggle svg { width: 14px; height: 14px; }
html[data-theme="light"] .icon-sun { display: none; }
html[data-theme="dark"] .icon-moon { display: none; }

/* ---------- layout primitives ---------- */
.page { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gutter); }
.section { padding: clamp(3rem, 7vw, 5.5rem) 0 0; }
.section-rule { border: none; border-top: var(--rule-w) solid var(--rule); margin: 0; }

.section-head { display: flex; align-items: baseline; gap: 1rem; margin-bottom: 1.4rem; }
.section-head h2 {
  font-family: var(--serif); font-weight: 560;
  font-size: var(--step-2); line-height: 1.15;
  margin: 0; color: var(--ink);
  text-wrap: balance;
  letter-spacing: -0.01em;
}
.section-head .count {
  font-family: var(--mono); font-size: 0.72rem;
  color: var(--faint); letter-spacing: 0.1em;
}
.section-head .more {
  margin-left: auto; font-size: var(--step--1); font-weight: 500;
  color: var(--muted); border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.section-head .more:hover { color: var(--accent); border-bottom-color: var(--accent); }

.lede {
  font-size: var(--step-1);
  line-height: 1.55;
  color: var(--muted);
  max-width: 58ch;
  text-pretty: hyphens none;
}

/* ---------- hero ---------- */
.hero {
  padding: clamp(2.8rem, 8vw, 6.5rem) 0 clamp(2.2rem, 5vw, 3.8rem) 0;
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(2rem, 5vw, 5rem);
  align-items: end;
}
.hero-kicker {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--accent);
  margin: 0 0 1.3rem;
}
.hero h1 {
  font-family: var(--serif);
  font-weight: 620;
  font-size: var(--step-4);
  line-height: 1.04;
  letter-spacing: -0.022em;
  margin: 0 0 1.6rem;
  color: var(--hero-ink);
  text-wrap: balance;
  font-variation-settings: "SOFT" 0, "WONK" 1;
}
.hero h1 em { font-style: italic; font-weight: 520; }
.hero-body {
  font-size: var(--step-0);
  color: var(--muted);
  max-width: 34em;
  margin: 0 0 1.8rem;
  text-pretty;
}
.hero-cta { display: flex; gap: 1.4rem; align-items: center; flex-wrap: wrap; }
.cta-primary {
  font-family: var(--mono); font-size: 0.8rem;
  letter-spacing: 0.04em;
  color: var(--bg);
  background: var(--bg-ink);
  padding: 0.7rem 1.3rem;
  border-radius: 3px;
  transition: background-color 0.2s ease, color 0.2s ease;
  touch-action: manipulation;
}
html[data-theme="light"] .cta-primary:hover { background: var(--accent); color: #fff; }
html[data-theme="dark"] .cta-primary:hover { background: var(--accent); color: #191311; }
.cta-quiet {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  font-size: var(--step--1); font-weight: 600;
  color: var(--muted);
  border-bottom: 1px solid var(--rule-strong);
  padding-bottom: 1px;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.cta-quiet::after { content: "\2192"; font-family: var(--mono); font-size: 0.85em; color: var(--faint); transition: color 0.2s ease, transform 0.2s ease; }
.cta-quiet:hover { color: var(--accent); border-bottom-color: var(--accent); }
.cta-quiet:hover::after { color: var(--accent); transform: translateX(2px); }

/* hero figure — a real law from the program */
.hero-fig {
  border: var(--rule-w) solid var(--rule);
  border-radius: 4px;
  background: var(--fig-bg);
  padding: 1.1rem 1.1rem 0.85rem;
  box-shadow: var(--shadow);
}
.hero-fig svg { display: block; width: 100%; height: auto; }
.fig-caption {
  margin-top: 1rem;
  padding-top: 0.7rem;
  border-top: var(--rule-w) solid var(--rule);
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  color: var(--muted);
  line-height: 1.55;
}
.fig-caption .fig-no { color: var(--accent); }

/* ---------- stats strip ---------- */
.stats {
  border-top: var(--rule-w) solid var(--rule);
  border-bottom: var(--rule-w) solid var(--rule);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 1.1rem 0;
  margin: clamp(1.5rem, 4vw, 3rem) 0 0;
}
.stat { padding: 0 1.4rem; border-left: var(--rule-w) solid var(--rule); }
.stat:first-child { border-left: none; padding-left: 0; }
.stat .n {
  font-family: var(--serif); font-weight: 600;
  font-size: var(--step-3);
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}
.stat .l {
  font-size: 0.78rem;
  color: var(--muted);
  margin-top: 0.35rem;
  line-height: 1.4;
}

/* ---------- paper TOC rows (journal contents) ---------- */
.toc { border-top: var(--rule-w) solid var(--rule-strong); }
.toc-series-label {
  font-family: var(--mono); font-size: 0.7rem;
  letter-spacing: 0.13em;
  color: var(--accent);
  padding: 1.1rem 0 0.2rem;
  display: flex; justify-content: space-between; gap: 1rem;
  flex-wrap: wrap;
}
.toc-series-label .ser-range { color: var(--faint); }
.toc-row {
  display: grid;
  grid-template-columns: 4.6rem minmax(0, 1fr) auto;
  gap: 1.6rem;
  align-items: baseline;
  padding: 1.05rem 0;
  border-bottom: var(--rule-w) solid var(--rule);
}
.toc-row:last-child { border-bottom: none; }
.toc-id {
  font-family: var(--mono); font-size: 0.78rem;
  color: var(--accent);
  letter-spacing: 0.03em;
  font-variant-numeric: tabular-nums;
}
.toc-main { min-width: 0; }
.toc-title {
  font-family: var(--serif); font-weight: 540;
  font-size: var(--step-1);
  line-height: 1.25;
  color: var(--ink);
  margin: 0;
  letter-spacing: -0.008em;
  transition: color 0.2s ease;
}
.toc-title a { display: inline-block; }
.toc-row:hover .toc-title { color: var(--accent); }
.toc-dek {
  font-size: var(--step--1);
  color: var(--muted);
  margin: 0.4rem 0 0;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-pretty;
}
.toc-links {
  display: flex; gap: 1.2rem;
  font-family: var(--mono); font-size: 0.78rem;
  letter-spacing: 0.05em;
  white-space: nowrap;
}
.toc-links a { color: var(--text); border-bottom: 1px solid var(--rule); }
.toc-links a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.toc-links a.toc-pdf { color: var(--ink); }
.toc-links a.toc-pdf:hover { color: var(--accent); }
.toc-links a.toc-essay { color: var(--accent); }
.toc-links a.toc-essay:hover { border-bottom-color: var(--accent); }
.toc-links a.toc-data { color: var(--muted); }
.toc-links a.toc-data:hover { color: var(--accent); border-bottom-color: var(--accent); }

.toc-tags {
  display: flex; gap: 0.5rem; margin-top: 0.5rem; flex-wrap: wrap;
}
.toc-tag {
  font-family: var(--mono); font-size: 0.64rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  border: 1px solid var(--rule);
  border-radius: 2px;
  padding: 0.1rem 0.45rem;
}

/* ---------- series volumes ---------- */
.volumes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1px;
  background: var(--rule);
  border: var(--rule-w) solid var(--rule);
}
.volume {
  background: var(--bg);
  padding: 1.5rem 1.4rem 1.3rem;
  transition: background-color 0.25s ease;
}
.volume { position: relative; }
.volume::after {
  content: "";
  position: absolute;
  top: 0; bottom: 0; left: 0;
  width: 2px;
  background: var(--accent);
  opacity: 0;
  transition: opacity 0.25s ease;
}
.volume:hover::after { opacity: 1; }
.volume:hover { background: var(--bg-soft); }
a.volume { text-decoration: none; }
.volume-charter .vol-num { font-family: var(--serif); font-style: italic; }
.volume-charter:hover .vol-name { color: var(--accent); }
.volume-charter { border-left: 2px solid var(--accent); }
.vol-num {
  font-family: var(--serif); font-weight: 620;
  font-size: 1.9rem; line-height: 1;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.vol-name {
  font-family: var(--serif); font-weight: 550;
  font-size: 1.06rem;
  color: var(--ink);
  margin: 0.55rem 0 0.3rem;
  line-height: 1.3;
}
.vol-range {
  font-family: var(--mono); font-size: 0.66rem;
  letter-spacing: 0.1em;
  color: var(--faint);
}
.vol-desc {
  font-size: 0.82rem;
  color: var(--muted);
  margin: 0.6rem 0 0;
  line-height: 1.55;
}

/* ---------- method cards ---------- */
.method-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1px;
  background: var(--rule);
  border: var(--rule-w) solid var(--rule);
}
.method-card {
  background: var(--bg);
  padding: 1.45rem 1.4rem 1.3rem;
  position: relative;
  transition: background-color 0.25s ease;
}
.method-card::after {
  content: "";
  position: absolute;
  top: 0; bottom: 0; left: 0;
  width: 2px;
  background: var(--accent);
  opacity: 0;
  transition: opacity 0.25s ease;
}
.method-card:hover { background: var(--bg-soft); }
.method-card:hover::after { opacity: 1; }
.method-card .m-n {
  font-family: var(--mono); font-size: 0.68rem;
  color: var(--accent); letter-spacing: 0.12em;
}
.method-card h3 {
  font-family: var(--serif); font-weight: 560;
  font-size: 1.08rem; line-height: 1.3;
  margin: 0.5rem 0 0.45rem;
  color: var(--ink);
}
.method-card p {
  font-size: 0.84rem; color: var(--muted);
  margin: 0; line-height: 1.6;
}

/* ---------- essays ---------- */
.essay-row {
  display: grid;
  grid-template-columns: 7.5rem minmax(0, 1fr) auto;
  gap: 1.6rem;
  align-items: baseline;
  padding: 1.15rem 0;
  border-bottom: var(--rule-w) solid var(--rule);
}
.essay-row:first-of-type { border-top: var(--rule-w) solid var(--rule-strong); }
.essay-date {
  font-family: var(--mono); font-size: 0.7rem;
  color: var(--muted);
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
}
.essay-title {
  font-family: var(--serif); font-weight: 540;
  font-size: var(--step-1); line-height: 1.3;
  color: var(--ink); margin: 0;
  transition: color 0.2s ease;
  letter-spacing: -0.008em;
}
.essay-row:hover .essay-title { color: var(--accent); }
.essay-dek {
  font-size: var(--step--1); color: var(--muted);
  margin: 0.35rem 0 0; line-height: 1.55;
}
.essay-arrow {
  font-family: var(--mono);
  color: var(--faint);
  transition: color 0.2s ease, transform 0.2s ease;
}
.essay-row:hover .essay-arrow { color: var(--accent); transform: translateX(3px); }

/* ---------- prose sections ---------- */
.prose { max-width: var(--measure); }
.prose p { margin: 0 0 1.1rem; text-pretty; }
.prose h3 {
  font-family: var(--serif); font-weight: 560;
  font-size: var(--step-1); color: var(--ink);
  margin: 2.2rem 0 0.8rem;
}
.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: start;
}

/* ---------- footer ---------- */
.site-footer {
  margin-top: clamp(3.5rem, 8vw, 6rem);
  border-top: var(--rule-w) solid var(--rule-strong);
  padding: 2.2rem 0 2.8rem;
}
.footer-inner {
  max-width: var(--maxw); margin: 0 auto;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 2.5rem;
  align-items: start;
}
.f-brand {
  font-family: var(--serif); font-weight: 640;
  font-size: 1.35rem; color: var(--ink);
}
.f-note { font-size: 0.8rem; color: var(--muted); margin-top: 0.4rem; max-width: 44ch; line-height: 1.6; }
.f-colophon {
  font-family: var(--mono); font-size: 0.66rem;
  color: var(--muted); letter-spacing: 0.07em;
  margin-top: 1.1rem; line-height: 1.7;
}
.footer-links {
  display: flex; flex-wrap: wrap; gap: 1.4rem;
  font-size: var(--step--1); justify-content: flex-end;
}
.footer-links a { color: var(--muted); }
.footer-links a:hover { color: var(--accent); }

/* ---------- reveal motion (compositor-friendly) ---------- */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.55s cubic-bezier(0.2, 0.7, 0.2, 1),
              transform 0.55s cubic-bezier(0.2, 0.7, 0.2, 1);
}
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .essay-row:hover .essay-arrow { transform: none; }
  body { transition: none; }
  * { scroll-behavior: auto; }
}

/* ---------- ledger table (method page) ---------- */
.ledger {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.86rem;
  border-top: var(--rule-w) solid var(--rule-strong);
}
.ledger th {
  font-family: var(--mono); font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--faint);
  text-align: left;
  font-weight: 500;
  padding: 0.7rem 1rem 0.5rem 0;
  border-bottom: var(--rule-w) solid var(--rule-strong);
}
.ledger td {
  padding: 0.55rem 1rem 0.55rem 0;
  border-bottom: var(--rule-w) solid var(--rule);
  vertical-align: top;
}
.ledger td:first-child {
  font-family: var(--mono); font-size: 0.74rem;
  color: var(--accent);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}
.ledger td:last-child {
  font-family: var(--mono); font-size: 0.7rem;
  color: var(--muted);
  white-space: nowrap;
}
.ledger tr:hover td { background: var(--bg-soft); }

/* ---------- 404 ---------- */
.err-fig {
  font-family: var(--serif); font-weight: 620;
  font-size: clamp(5rem, 18vw, 11rem);
  line-height: 0.95;
  color: var(--ink);
  letter-spacing: -0.03em;
}
.err-fig .accent { color: var(--accent); }

/* ---------- essay post (blog/*.html) ---------- */
.post {
  max-width: 46rem;
  margin: 0 auto;
  padding: clamp(2.6rem, 7vw, 5rem) 0 0;
}
.post-head { border-bottom: var(--rule-w) solid var(--rule); padding-bottom: 1.6rem; }
.post-title {
  font-family: var(--serif); font-weight: 620;
  font-size: var(--step-3);
  line-height: 1.08; letter-spacing: -0.018em;
  margin: 0 0 1rem;
  color: var(--ink);
  text-wrap: balance;
}
.post-meta {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.post-body { padding-top: 1.8rem; }
.post-body p {
  margin: 0 0 1.25rem;
  font-size: var(--step-0);
  line-height: 1.75;
  text-pretty;
}
.post-body p:first-of-type::first-letter {
  font-family: var(--serif);
  font-size: 3.2em;
  float: left;
  line-height: 0.82;
  padding: 0.06em 0.09em 0 0;
  color: var(--accent);
  font-weight: 600;
}
.post-body h2 {
  font-family: var(--serif); font-weight: 580;
  font-size: var(--step-1);
  line-height: 1.25;
  margin: 2.6rem 0 0.9rem;
  color: var(--ink);
  letter-spacing: -0.008em;
  text-wrap: balance;
}
.post-body h3 {
  font-family: var(--sans); font-weight: 650;
  font-size: 1.02rem;
  margin: 2rem 0 0.7rem;
  color: var(--ink);
}
.post-body ul, .post-body ol {
  padding-left: 1.5rem;
  margin: 0 0 1.25rem;
  line-height: 1.7;
}
.post-body li { margin-bottom: 0.45rem; }
.post-body blockquote {
  margin: 1.8rem 0;
  padding: 0.2rem 0 0.2rem 1.4rem;
  border-left: 2px solid var(--accent);
  color: var(--muted);
  font-style: italic;
}
.post-body blockquote p { margin: 0 0 0.6rem; }
.post-body code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--accent-soft);
  border-radius: 2px;
  padding: 0.1em 0.35em;
}
.post-body hr {
  border: none;
  border-top: var(--rule-w) solid var(--rule);
  margin: 2.6rem 0;
}
.post-body a { border-bottom: 1px solid var(--rule-strong); }
.post-body a:hover { border-bottom-color: var(--accent); }
.post-footer {
  margin-top: 2.8rem;
  padding: 1.3rem 1.4rem;
  border: var(--rule-w) solid var(--rule);
  border-left: 2px solid var(--accent);
  border-radius: 3px;
  background: var(--card);
}
.post-footer p { margin: 0; font-size: 0.86rem; color: var(--muted); line-height: 1.65; }
@media (prefers-reduced-motion: reduce) {
  .post-body p:first-of-type::first-letter { color: var(--accent); }
}

/* ---------- page hero (inner pages) ---------- */
.page-head { padding: clamp(2.4rem, 6vw, 4.2rem) 0 0; }
.page-head h1 {
  font-family: var(--serif); font-weight: 620;
  font-size: var(--step-3);
  line-height: 1.08; letter-spacing: -0.018em;
  margin: 0 0 1rem;
  color: var(--ink);
  text-wrap: balance;
}
.page-head .lede { margin-bottom: 1.6rem; }
.page-meta {
  display: flex; flex-wrap: wrap; gap: 0.55rem; align-items: center;
  font-family: var(--mono); font-size: 0.68rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--faint); margin: 0 0 0.4rem;
}
.page-meta span[aria-hidden='true'] { color: var(--rule); }

/* ---------- series filter chips ---------- */
.chip-row {
  display: flex; gap: 0.5rem; flex-wrap: wrap;
  margin: 0 0 1.4rem;
}
.chip {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.09em;
  color: var(--muted);
  background: none;
  border: 1px solid var(--rule);
  border-radius: 2px;
  padding: 0.34rem 0.8rem;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
  touch-action: manipulation;
}
.chip:hover { color: var(--ink); border-color: var(--rule-strong); }
.chip.is-on {
  color: var(--bg);
  background: var(--bg-ink);
  border-color: var(--bg-ink);
}
html[data-theme="dark"] .chip.is-on { color: #15161a; }

/* ---------- figures at a glance strip ---------- */
.fig-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.1rem;
  margin: 0 0 0.6rem;
}
.fig-card {
  display: block;
  border: var(--rule-w) solid var(--rule);
  border-radius: 4px;
  background: var(--fig-bg);
  padding: 0.55rem 0.55rem 0.5rem;
  transition: border-color 0.25s ease, transform 0.25s ease;
}
.fig-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.fig-card img { display: block; width: 100%; height: auto; border-radius: 2px; }
.fig-card-cap {
  display: block;
  margin-top: 0.6rem;
  font-family: var(--mono); font-size: 0.68rem;
  letter-spacing: 0.04em;
  color: var(--text);
  line-height: 1.5;
}
.fig-card-cap .fig-no { color: var(--accent); }

/* ---------- cite / bibtex ---------- */
.cite-details {
  border: var(--rule-w) solid var(--rule);
  border-radius: 4px;
  background: var(--card);
  margin-top: 1.4rem;
}
.cite-details summary {
  cursor: pointer;
  padding: 0.9rem 1.2rem;
  font-family: var(--mono); font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  list-style: none;
  touch-action: manipulation;
}
.cite-details summary::before { content: "+ "; color: var(--accent); }
.cite-details[open] summary::before { content: "− "; }
.cite-details summary:hover { color: var(--ink); }
.bibtex-block {
  margin: 0;
  padding: 0 1.2rem 1.1rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  line-height: 1.65;
  color: var(--text);
  overflow-x: auto;
  white-space: pre;
}
.bibtex-block::-webkit-scrollbar { height: 6px; }
.bibtex-block::-webkit-scrollbar-thumb { background: var(--rule); border-radius: 3px; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; align-items: start; }
  .hero-fig { max-width: 560px; }
  .stats { grid-template-columns: repeat(2, 1fr); row-gap: 1.2rem; }
  .stat:nth-child(odd) { border-left: none; padding-left: 0; }
  .stat:nth-child(even) { padding-right: 0; }
  .about-grid { grid-template-columns: 1fr; }
  .toc-row { grid-template-columns: 3.6rem minmax(0, 1fr); }
  .toc-links { grid-column: 2; margin-top: 0.4rem; }
  .essay-row { grid-template-columns: minmax(0, 1fr); gap: 0.3rem; }
  .essay-arrow { display: none; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
  .masthead { gap: 1rem; }
  .masthead nav { gap: 1rem; }
  .brand-sub { display: none; }
}
@media (max-width: 560px) {
  .masthead nav { display: none; }
  .masthead .nav-toggle { display: inline-flex; }
}

/* ---------- print ---------- */
@media print {
  .site-header, .theme-toggle, .hero-fig, .site-footer, .skip { display: none; }
  body { background: #fff; color: #000; }
  .toc-row, .essay-row { break-inside: avoid; }
}

/* source links in paper rows — raw markdown on GitHub */
.toc-links a.toc-src::after { content: " \2197"; font-size: 0.85em; color: var(--faint); }
.toc-links a.toc-src { font-family: var(--mono); font-size: 0.95em; }

/* ---------- focus & selection (app apparatus) ---------- */
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}
::selection { background: var(--accent-soft); color: var(--ink); }

/* ---------- mobile nav toggle (injected by reveal.js) ---------- */
.masthead { position: relative; }
.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--rule);
  color: var(--muted);
  width: 2rem; height: 2rem;
  border-radius: 999px;
  align-items: center; justify-content: center;
  cursor: pointer;
  flex: none;
  transition: color 0.2s ease, border-color 0.2s ease;
  touch-action: manipulation;
}
.nav-toggle:hover { color: var(--ink); border-color: var(--rule-strong); }
.nav-toggle svg { width: 15px; height: 15px; }
@media (max-width: 560px) {
  .masthead .nav-toggle { display: inline-flex; }
  .masthead nav {
    display: none;
    position: absolute;
    top: 100%; left: 0; right: 0;
    background: var(--bg);
    border-bottom: var(--rule-w) solid var(--rule);
    box-shadow: var(--shadow);
    flex-direction: column;
    gap: 0;
    margin-left: 0;
    padding: 0.35rem var(--gutter) 0.9rem;
    z-index: 90;
  }
  .masthead nav.open { display: flex; }
  .masthead nav a {
    padding: 0.72rem 0;
    border-bottom: var(--rule-w) solid var(--rule);
    font-size: 0.95rem;
  }
  .masthead nav a:last-child { border-bottom: none; }
}

/* ---------- back to top (injected by reveal.js) ---------- */
.top-btn {
  position: fixed;
  right: clamp(1rem, 3vw, 2rem);
  bottom: clamp(1rem, 3vw, 2rem);
  width: 2.4rem; height: 2.4rem;
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--bg-raise);
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
  z-index: 80;
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  box-shadow: var(--shadow);
  transition: opacity 0.25s ease, transform 0.25s ease,
              color 0.2s ease, border-color 0.2s ease;
  touch-action: manipulation;
}
.top-btn.show { opacity: 1; transform: none; pointer-events: auto; }
.top-btn:hover { color: var(--accent); border-color: var(--accent); }
.top-btn svg { width: 14px; height: 14px; }
@media (prefers-reduced-motion: reduce) { .top-btn { transition: none; } }

/* ---------- paper search (papers.html) ---------- */
.paper-search {
  display: flex; align-items: center; gap: 0.9rem;
  flex-wrap: wrap;
  margin: 0 0 1.4rem;
}
.paper-search input {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.02em;
  color: var(--text);
  background: var(--bg-raise);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.5rem 0.9rem;
  width: min(430px, 100%);
  transition: border-color 0.2s ease;
}
.paper-search input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 0;
  border-color: var(--accent);
}
.paper-search input::placeholder { color: var(--faint); }
.paper-search input::-webkit-search-cancel-button { -webkit-appearance: none; }
.q-count {
  font-family: var(--mono); font-size: 0.68rem;
  letter-spacing: 0.07em;
  color: var(--faint);
  font-variant-numeric: tabular-nums;
}
.q-empty {
  font-family: var(--mono); font-size: 0.78rem;
  color: var(--muted);
  padding: 1.4rem 0 0.4rem;
  display: none;
}
.q-empty.on { display: block; }

/* ---------- keyboard hint in footer ---------- */
.f-colophon kbd {
  font-family: var(--mono);
  font-size: 0.92em;
  border: 1px solid var(--rule);
  border-bottom-width: 2px;
  border-radius: 3px;
  padding: 0 0.3em;
  color: var(--text);
}

@media print {
  .top-btn, .nav-toggle { display: none !important; }
  .paper-search, .chip-row { display: none; }
}

/* ---------- explainer page (layernorm.html) — production pass ---------- */

/* chapter system: numbered sections with hairline rules and real air */
.prose .chapter { margin-top: clamp(3.4rem, 8vw, 5.2rem); }
.prose .chapter:first-of-type { margin-top: 2.2rem; }
.chapter-eyebrow {
  display: flex; align-items: center; gap: 0.9rem;
  margin: 0 0 1.1rem;
}
.chapter-eyebrow .ch-no {
  font-family: var(--mono); font-size: 0.78rem; font-weight: 500;
  letter-spacing: 0.14em; color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.chapter-eyebrow .ch-rule {
  flex: 1; border: none; border-top: var(--rule-w) solid var(--rule);
  margin: 0;
}
.chapter-eyebrow .ch-tag {
  font-family: var(--mono); font-size: 0.64rem;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--faint);
}
.prose h2 {
  font-family: var(--serif); font-weight: 560;
  font-size: var(--step-2); color: var(--ink);
  margin: 0 0 1.1rem; line-height: 1.15;
  text-wrap: balance;
}
.prose h2 + p { margin-top: 0; }

/* display math: anchored, with air, sized to read */
.prose .katex-display {
  margin: 2rem 0 2.1rem;
  padding: 0.25rem 0.5rem;
  overflow-x: auto; overflow-y: hidden;
}
.prose .katex-display > .katex { font-size: 1.12em; }

/* the short version (summary card at top of explainer) */
.short-version {
  border: var(--rule-w) solid var(--rule-strong);
  border-left: 3px solid var(--accent);
  border-radius: 4px 10px 10px 4px;
  background: var(--bg-raise);
  padding: 1.15rem 1.3rem 1.05rem;
  margin: 1.8rem 0 1rem;
}
.short-version .sv-head {
  font-family: var(--mono); font-size: 0.7rem; font-weight: 500;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 0.7rem;
}
.short-version ol { margin: 0; padding-left: 1.25rem; }
.short-version li {
  margin: 0 0 0.5rem; font-size: 0.88rem; line-height: 1.55;
  color: var(--text);
}
.short-version li:last-child { margin-bottom: 0; }
.short-version li strong { color: var(--ink); font-weight: 600; }

/* run-status card: honest experiment ledger (what has run / what is next) */
.status-card {
  border: var(--rule-w) solid var(--rule);
  border-radius: 10px;
  background: var(--bg-raise);
  padding: 1.05rem 1.25rem 0.95rem;
  margin: 1.7rem 0 1.9rem;
}
.status-card .st-head {
  display: flex; align-items: center; gap: 0.6rem;
  font-family: var(--mono); font-size: 0.7rem; font-weight: 500;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 0.75rem;
}
.status-card .st-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent); flex: 0 0 auto;
}
.status-card table { width: 100%; border-collapse: collapse; }
.status-card td {
  padding: 0.42rem 0.6rem 0.42rem 0;
  border-bottom: var(--rule-w) solid var(--rule);
  font-size: 0.82rem; color: var(--text); vertical-align: top;
}
.status-card tr:last-child td { border-bottom: none; }
.status-card td.st-exp {
  font-family: var(--mono); font-size: 0.72rem; color: var(--ink);
  white-space: nowrap; padding-right: 1rem;
}
.status-card td.st-state { white-space: nowrap; }
.status-card .st-pending { color: var(--muted); }
.status-card .st-done { color: var(--accent); font-weight: 600; }
.status-card .st-note { color: var(--muted); font-size: 0.76rem; }
.status-card .st-foot {
  font-size: 0.72rem; color: var(--muted); line-height: 1.5;
  margin: 0.7rem 0 0;
}
.status-card .st-foot a { color: var(--accent); }

/* instrument plates (interactive demos) — components, not fieldsets */
.demo {
  border: var(--rule-w) solid var(--rule);
  border-radius: 10px;
  background: var(--bg-raise);
  padding: 0;
  margin: 2rem 0 2.2rem;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.demo-head {
  display: flex; align-items: center; gap: 0.7rem;
  padding: 0.65rem 1.1rem;
  border-bottom: var(--rule-w) solid var(--rule);
  background: var(--bg-soft);
  font-family: var(--mono); font-size: 0.68rem; font-weight: 500;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--accent);
}
.demo-head .live-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--accent); flex: 0 0 auto;
}
.demo-head .demo-subhead {
  margin-left: auto; color: var(--faint); letter-spacing: 0.1em;
  font-size: 0.62rem;
}
.demo-body { padding: 1.05rem 1.15rem 1rem; }
.demo-row {
  display: flex; align-items: center; gap: 0.9rem;
  margin: 0 0 0.7rem;
}
.demo-row label {
  flex: 0 0 8.8rem; font-family: var(--mono);
  font-size: 0.7rem; color: var(--muted);
}
.demo-row input[type="range"] {
  flex: 1; min-width: 0;
  -webkit-appearance: none; appearance: none;
  height: 22px; background: transparent; cursor: pointer;
}
.demo-row input[type="range"]:focus {
  outline: none;
}
.demo-row input[type="range"]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px; border-radius: 4px;
}
.demo-row input[type="range"]::-webkit-slider-runnable-track {
  height: 4px; border-radius: 2px;
  background: var(--rule);
}
.demo-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 15px; height: 15px; border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent);
  margin-top: -5.5px;
  transition: transform 0.12s ease;
}
.demo-row input[type="range"]:hover::-webkit-slider-thumb,
.demo-row input[type="range"]:active::-webkit-slider-thumb {
  transform: scale(1.18);
}
.demo-row input[type="range"]::-moz-range-track {
  height: 4px; border-radius: 2px; background: var(--rule);
}
.demo-row input[type="range"]::-moz-range-thumb {
  width: 11px; height: 11px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
  box-sizing: content-box;
}
.demo-row output {
  flex: 0 0 4rem; text-align: right; font-size: 0.82rem;
  font-family: var(--mono); color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.demo-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem;
  margin-top: 0.9rem;
}
.demo-cell {
  border: var(--rule-w) solid var(--rule);
  border-radius: 7px; padding: 0.7rem 0.85rem 0.6rem;
  background: var(--bg);
}
.demo-label {
  font-family: var(--mono); font-size: 0.64rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 0.35rem;
}
.demo-val {
  font-family: var(--mono); font-size: 0.8rem;
  color: var(--ink); word-break: break-all;
  font-variant-numeric: tabular-nums;
  line-height: 1.45;
}
.demo-cell.out .demo-val { color: var(--accent); }
.demo-sub {
  font-family: var(--mono); font-size: 0.66rem; color: var(--muted);
  margin-top: 0.3rem; font-variant-numeric: tabular-nums;
}
.demo-note {
  font-size: 0.73rem; color: var(--muted);
  margin: 0.9rem 1.15rem 0; padding-bottom: 0.4rem;
  line-height: 1.55;
}
.demo-note a { color: var(--accent); }
.demo-note + .demo-note { margin-top: 0; }

/* comparison meters (port-budget plate) */
.bars { margin-top: 0.95rem; }
.bar-row {
  display: grid; grid-template-columns: 7.2rem 1fr 5rem;
  align-items: center; gap: 0.8rem; margin: 0 0 0.6rem;
}
.bar-name {
  font-family: var(--mono); font-size: 0.66rem;
  letter-spacing: 0.06em; color: var(--muted);
}
.bar-track {
  height: 8px; border-radius: 4px; overflow: hidden;
  background: var(--rule);
  position: relative;
}
.bar-fill {
  height: 100%; min-width: 3px;
  transition: width 0.22s cubic-bezier(0.22, 0.61, 0.36, 1);
}
.bar-ph {
  background: var(--accent);
  border-radius: 4px 0 0 4px;
}
/* the unmanaged stream reads as a hazard: muted diagonal stripes */
.bar-un {
  border-radius: 4px 0 0 4px;
  background: repeating-linear-gradient(
    -45deg,
    var(--faint), var(--faint) 4px,
    transparent 4px, transparent 8px);
}
.bar-val {
  text-align: right; font-family: var(--mono); font-size: 0.74rem;
  color: var(--ink); font-variant-numeric: tabular-nums;
}

/* data tables: numbers right-aligned, headers that read as headers */
.prose table.ledger { margin: 1.5rem 0 1.7rem; }
.prose table.ledger th {
  font-family: var(--mono); font-size: 0.66rem;
  letter-spacing: 0.13em; text-transform: uppercase;
  color: var(--faint); text-align: left; font-weight: 500;
  padding: 0.55rem 0.9rem 0.45rem 0;
  border-bottom: 2px solid var(--rule-strong);
  white-space: nowrap;
}
.prose table.ledger th.num,
.prose table.ledger td.num {
  text-align: right; font-variant-numeric: tabular-nums;
  padding-right: 0; white-space: nowrap;
}
.prose table.ledger td {
  padding: 0.6rem 0.9rem 0.6rem 0;
  border-bottom: var(--rule-w) solid var(--rule);
  vertical-align: top;
}
.prose table.ledger td:first-child {
  font-weight: 500; color: var(--ink);
}
.prose table.ledger td.num {
  font-family: var(--mono); font-size: 0.78rem; color: var(--text);
}
.prose table.ledger tr:hover td { background: var(--bg-soft); }
.prose table.ledger td .best {
  color: var(--accent); font-weight: 600;
}
.prose table.ledger td .pending-note {
  font-family: var(--sans); font-size: 0.72rem; color: var(--muted);
}
.prose ol.steps {
  margin: 0 0 1.2rem; padding-left: 1.4rem;
}
.prose ol.steps li {
  margin: 0 0 0.55rem; text-pretty;
}
.mono { font-family: var(--mono); }

/* ---------- image lightbox (site-wide, auto-injected) ---------- */
.lb-overlay {
  position: fixed; inset: 0; z-index: 200;
  display: flex; align-items: center; justify-content: center;
  background: color-mix(in srgb, var(--bg-ink) 78%, transparent);
  -webkit-backdrop-filter: blur(10px) saturate(0.85);
  backdrop-filter: blur(10px) saturate(0.85);
  opacity: 0; transition: opacity 0.18s ease;
}
.lb-overlay.open { opacity: 1; }
.lb-overlay:not(.open) { pointer-events: none; }
.lb-fig {
  margin: 0; max-width: min(94vw, 1500px);
  display: flex; flex-direction: column; align-items: center; gap: 0.7rem;
  transform: scale(0.985); transition: transform 0.18s ease;
}
.lb-overlay.open .lb-fig { transform: scale(1); }
.lb-fig img {
  max-width: 94vw; max-height: 84vh;
  border-radius: 4px;
  background: #fff;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
  display: block;
}
.lb-cap {
  max-width: 72ch; padding: 0 1.4rem;
  font-family: var(--mono); font-size: 0.72rem; line-height: 1.55;
  color: var(--bg-raise);
  text-align: center;
}
html[data-theme='light'] .lb-cap { color: #f5f2ea; }
.lb-cap .lb-no { color: var(--accent); font-weight: 500; }
.lb-close {
  position: absolute; top: 1.1rem; right: 1.2rem;
  width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(0, 0, 0, 0.35); color: #fff;
  font-size: 1.25rem; line-height: 1; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s ease, transform 0.15s ease;
}
.lb-close:hover { background: rgba(0, 0, 0, 0.6); transform: scale(1.05); }
.lb-nav {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 44px; height: 44px; border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(0, 0, 0, 0.35); color: #fff; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s ease;
}
.lb-nav:hover { background: rgba(0, 0, 0, 0.6); }
.lb-prev { left: 1.2rem; }
.lb-next { right: 1.2rem; }
.lb-nav[hidden] { display: none; }
.lb-close:focus-visible, .lb-nav:focus-visible {
  outline: 2px solid #fff; outline-offset: 3px;
}
@media (prefers-reduced-motion: reduce) {
  .lb-overlay, .lb-fig, .lb-close, .bar-fill,
  .demo-row input[type="range"]::-webkit-slider-thumb { transition: none; }
}
@media (max-width: 620px) {
  .demo-grid { grid-template-columns: 1fr; }
  .demo-row label { flex-basis: 7rem; }
  .bar-row { grid-template-columns: 5.6rem 1fr 3.6rem; }
  .lb-prev { left: 0.4rem; } .lb-next { right: 0.4rem; }
  .prose table.ledger td.num, .prose table.ledger th.num { padding-left: 0.5rem; }
}

.x-links { margin-top: 2.6rem; border-top: var(--rule-w) solid var(--rule); padding-top: 1.4rem; }
.x-links-head {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 0.8rem;
}
.x-links p { display: flex; flex-wrap: wrap; gap: 1rem 1.4rem; align-items: center; margin: 0; }

@media (max-width: 640px) {
  .demo-grid { grid-template-columns: 1fr; }
  .demo-row label { flex-basis: 7.5rem; }
  .bar-row { grid-template-columns: 4.8rem 1fr 3.8rem; }
}