:root {
  --paper: #f2efe4;
  --card: #f7f4ea;
  --ink: #26221a;
  --ink-soft: #46402f;
  --muted: #7c715a;
  --faint: #a2957a;
  --leaf: #2f5a2c;
  --teal: #2c5a55;
  --ochre: #9a6414;
  --rust: #8a3b24;
  --slate: #3d5a78;
  --rule: #26221a;
  --hairline: #cfc7ae;
  --max: 720px;
  --wide: 1160px;
  --mono: "IBM Plex Mono", "SF Mono", Menlo, monospace;
  --display: "Fraunces", Georgia, serif;
  --body: "Source Serif 4", Georgia, serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 1.075rem;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

::selection { background: #dbe5d2; }

a { color: var(--ink); text-decoration-thickness: 1px; text-underline-offset: 3px; text-decoration-color: var(--faint); }
a:hover { color: var(--teal); text-decoration-color: currentColor; }

/* mono metadata voice */
.meta-line, .mins, .volume, .row-label, .listing-bar, .breadcrumb, .footer-bar {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}
.meta-line strong { color: var(--ink-soft); font-weight: 500; }

.kicker {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ochre);
  margin: 0 0 14px;
}

/* ---------- Masthead ---------- */
.masthead {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 34px 28px 0;
}
.masthead-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 24px;
}
.wordmark {
  font-family: var(--display);
  font-weight: 700;
  font-size: 2.1rem;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}
.wordmark em { font-style: italic; color: var(--leaf); }
.wordmark .mark { color: var(--ochre); font-size: 1.3rem; }
.volume {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 2px;
  text-align: right;
}
.masthead-sub {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 4px 0 18px;
}
.masthead-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 30px;
  border-top: 2px solid var(--rule);
  border-bottom: 1px solid var(--hairline);
  padding: 12px 0;
}
.masthead-nav a {
  font-family: var(--mono);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
  text-decoration: none;
}
.masthead-nav a:hover { color: var(--ochre); }

main { max-width: var(--wide); margin: 0 auto; padding: 0 28px; }

/* ---------- Home hero ---------- */
.hero { padding: 56px 0 48px; border-bottom: 1px solid var(--hairline); }
.hero h1 {
  font-family: var(--display);
  font-size: clamp(2.3rem, 5.5vw, 4rem);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0 0 22px;
  max-width: 15ch;
}
.hero h1 a { color: var(--ink); text-decoration: none; }
.hero h1 a:hover { color: var(--teal); }
.hero-dek {
  font-size: 1.18rem;
  line-height: 1.6;
  color: var(--ink-soft);
  max-width: 540px;
  margin: 0 0 22px;
}
.hero .meta-line { margin: 0; }

/* ---------- Browse by section ---------- */
.browse { padding: 44px 0 0; }
.browse-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 26px;
}
.browse-head h2 {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin: 0;
  color: var(--ink);
}
.section-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--hairline);
  background: var(--card);
}
.section-cell {
  padding: 32px 34px 28px;
  border-right: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
}
.section-cell:nth-child(2n) { border-right: 0; }
.section-cell:nth-last-child(-n+2) { border-bottom: 0; }
.section-cell h3 {
  font-family: var(--display);
  font-size: 1.55rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.section-cell .num {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 400;
  color: var(--faint);
}
.section-desc { color: var(--muted); font-size: 0.98rem; margin: 0 0 18px; }
.section-articles { list-style: none; margin: 0; padding: 0; }
.section-articles li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 11px 0;
  border-top: 1px solid var(--hairline);
}
.section-articles a {
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.02rem;
  text-decoration: none;
  color: var(--section-accent, var(--ochre));
}
.section-articles a:hover { text-decoration: underline; }
.section-articles .mins { white-space: nowrap; }
.section-more { margin: 14px 0 0; }
.section-more a {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
}
.section-more a:hover { color: var(--section-accent, var(--ochre)); }

.s-field-notes { --section-accent: var(--leaf); }
.s-new-science { --section-accent: var(--ochre); }
.s-first-principles { --section-accent: var(--slate); }
.s-app { --section-accent: var(--teal); }

/* ---------- App callout ---------- */
.app-callout {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
  border: 1px solid var(--rule);
  background: var(--card);
  padding: 22px 30px;
  margin: 48px 0 72px;
}
.app-callout .callout-title {
  font-family: var(--body);
  font-weight: 600;
  font-size: 1.05rem;
  margin: 0 0 4px;
  color: var(--ink);
}
.app-callout p { margin: 0; color: var(--muted); font-size: 0.98rem; }
.callout-link {
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink);
  white-space: nowrap;
}

/* ---------- Section pages ---------- */
.section-page { padding: 56px 0 60px; }
.section-page h1 {
  font-family: var(--display);
  font-size: clamp(2.4rem, 6vw, 3.8rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.05;
  margin: 0 0 16px;
}
.listing-bar {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  border-top: 2px solid var(--rule);
  border-bottom: 1px solid var(--hairline);
  padding: 10px 0;
  margin: 36px 0 0;
  color: var(--ink-soft);
}
.article-listing { list-style: none; margin: 0; padding: 0; }
.article-listing li {
  display: grid;
  grid-template-columns: 44px 1fr auto;
  gap: 20px;
  align-items: start;
  padding: 30px 0;
  border-bottom: 1px solid var(--hairline);
}
.article-listing .row-num { font-family: var(--mono); font-size: 0.78rem; color: var(--faint); padding-top: 10px; }
.article-listing .row-label { margin: 0 0 6px; color: var(--ochre); }
.article-listing h2 {
  font-family: var(--display);
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin: 0 0 8px;
}
.article-listing h2 a { text-decoration: none; }
.article-listing h2 a:hover { color: var(--teal); }
.article-listing .row-dek { margin: 0; color: var(--muted); font-size: 1rem; }
.article-listing .mins { padding-top: 12px; white-space: nowrap; }

/* ---------- Essay pages ---------- */
.essay { max-width: var(--max); margin: 0 auto; padding: 40px 0 30px; }
.breadcrumb { margin: 0 0 26px; }
.breadcrumb a { color: var(--ochre); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { color: var(--faint); margin: 0 4px; }
.essay-body h1 {
  font-family: var(--display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
}
/* dek — first italic paragraph after the title */
.essay-body h1 + p {
  font-size: 1.2rem;
  line-height: 1.6;
  color: var(--muted);
  margin: 0 0 18px;
}
.essay-body h1 + p::after {
  content: "";
  display: block;
  border-top: 1px solid var(--hairline);
  margin: 30px 0 6px;
}
/* drop cap on the first body paragraph */
.essay-body h1 + p + p::first-letter {
  font-family: var(--display);
  font-weight: 700;
  font-size: 3.6em;
  float: left;
  line-height: 0.8;
  padding: 8px 12px 0 0;
  color: var(--teal);
}
.essay-body h2 {
  font-family: var(--display);
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 48px 0 14px;
}
.essay-body img { max-width: 100%; }
.essay-body figure {
  margin: 40px 0;
  padding: 22px 22px 16px;
  background: #ffffff;
  border: 1px solid var(--hairline);
}
.essay-body figure img { display: block; width: 100%; height: auto; }
.essay-body figcaption {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--hairline);
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--muted);
}
.essay-body figcaption strong { color: var(--ink-soft); }
.essay-body figcaption em { font-size: 0.85rem; }
.essay-body blockquote {
  margin: 36px 0;
  padding: 4px 0 4px 26px;
  border-left: 3px solid var(--teal);
  font-family: var(--display);
  font-style: italic;
  font-weight: 400;
  font-size: 1.35rem;
  line-height: 1.45;
  color: var(--ink-soft);
}
.essay-body blockquote p { margin: 0; }
.essay-body hr { border: 0; border-top: 1px solid var(--hairline); margin: 44px auto; width: 140px; }

/* Sources */
.essay-body h2:last-of-type {
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  border-top: 2px solid var(--rule);
  padding-top: 24px;
  margin-top: 60px;
}
.essay-body h2:last-of-type ~ ul,
.essay-body h2:last-of-type ~ ol {
  font-size: 0.92rem;
  color: var(--muted);
  line-height: 1.65;
  padding-left: 20px;
}
.essay-body h2:last-of-type ~ ul li,
.essay-body h2:last-of-type ~ ol li { margin-bottom: 8px; }

.essay-meta-end { margin-top: 44px; }

.essay .app-callout { margin: 40px 0 50px; }

/* ---------- Static pages ---------- */
.page { max-width: var(--max); margin: 0 auto; padding: 56px 0 60px; }
.page h1 {
  font-family: var(--display);
  font-size: clamp(2rem, 5vw, 2.8rem);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
}
.page h1 + p { font-size: 1.15rem; color: var(--ink-soft); }
.page h2 {
  font-family: var(--display);
  font-size: 1.4rem;
  font-weight: 700;
  margin: 44px 0 12px;
}
.page ul li { margin-bottom: 8px; }

/* ---------- Footer ---------- */
.site-footer { margin-top: 20px; }
.footer-inner {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 36px 28px 44px;
  border-top: 2px solid var(--rule);
}
.footer-line {
  font-style: italic;
  font-size: 1rem;
  max-width: 560px;
  margin: 0 0 6px;
  color: var(--ink-soft);
}
.footer-attr {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin: 0 0 26px;
  color: var(--faint);
}
.footer-bar {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  border-top: 1px solid var(--hairline);
  padding-top: 16px;
}
.footer-bar a { color: var(--muted); }

@media (max-width: 760px) {
  .masthead { padding: 26px 20px 0; }
  main { padding: 0 20px; }
  .footer-inner { padding: 30px 20px 40px; }
  .section-grid { grid-template-columns: 1fr; }
  .section-cell { border-right: 0 !important; border-bottom: 1px solid var(--hairline) !important; }
  .section-cell:last-child { border-bottom: 0 !important; }
  .article-listing li { grid-template-columns: 1fr; gap: 4px; }
  .article-listing .row-num, .article-listing .mins { padding-top: 0; }
  .hero { padding: 40px 0 36px; }
  .volume { display: none; }
}