/* ============================================================
   Informopedia Hub v1.0.0 — main stylesheet
   Design system extracted from the approved homepage mockup
   (navy + amber, Source Serif 4 / Source Sans 3 / IBM Plex Mono)
   Dark mode: [data-theme="dark"] explicit, or OS preference when unset
   ============================================================ */

:root {
  color-scheme: light;
  --paper: #faf9f6;
  --surface: #ffffff;
  --surface-2: #f2f0ea;
  --ink: #16222e;
  --ink-soft: #44545f;
  --ink-faint: #6d7c86;
  --navy: #123252;
  --navy-deep: #0d2742;
  --amber: #b45309;
  --amber-bright: #d97706;
  --amber-soft: #fdf3e3;
  --teal: #0f766e;
  --teal-soft: #e6f4f1;
  --line: #e2ded2;
  --line-strong: #cfc9b8;
  --mark-bg: #0d2742;
  --btn-bg: #0d2742;
  --footer-bg: #0d2742;
  --shadow: 0 1px 2px rgba(18, 40, 66, .06), 0 10px 30px -18px rgba(18, 40, 66, .25);
  --radius: 10px;
}

/* Explicit dark theme (toggle) */
[data-theme="dark"] {
  color-scheme: dark;
  --paper: #0a111c;
  --surface: #101a29;
  --surface-2: #0d1624;
  --ink: #e9edf2;
  --ink-soft: #b3c0cc;
  --ink-faint: #8496a5;
  --navy: #7aa7d9;
  --amber: #e8a33d;
  --amber-bright: #f0b25c;
  --amber-soft: #2a2113;
  --teal: #4cc2b4;
  --teal-soft: #0e2a27;
  --line: #22344a;
  --line-strong: #2f4763;
  --mark-bg: #173d63;
  --btn-bg: #1d4e79;
  --footer-bg: #060c15;
  --shadow: 0 1px 2px rgba(0,0,0,.4), 0 12px 32px -18px rgba(0,0,0,.7);
}

/* OS-preference dark when no explicit choice stored */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --paper: #0a111c;
    --surface: #101a29;
    --surface-2: #0d1624;
    --ink: #e9edf2;
    --ink-soft: #b3c0cc;
    --ink-faint: #8496a5;
    --navy: #7aa7d9;
    --amber: #e8a33d;
    --amber-bright: #f0b25c;
    --amber-soft: #2a2113;
    --teal: #4cc2b4;
    --teal-soft: #0e2a27;
    --line: #22344a;
    --line-strong: #2f4763;
    --mark-bg: #173d63;
    --btn-bg: #1d4e79;
    --footer-bg: #060c15;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 12px 32px -18px rgba(0,0,0,.7);
  }
}

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Source Sans 3", system-ui, -apple-system, sans-serif;
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, h5, p, ul, ol, figure { margin: 0; }
ul, ol { padding: 0; }
img { display: block; max-width: 100%; height: auto; }
a { color: var(--navy); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--amber-bright); outline-offset: 2px;
}
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
.serif { font-family: "Source Serif 4", Georgia, serif; }
.mono { font-family: "IBM Plex Mono", ui-monospace, monospace; }
.screen-reader-text {
  border: 0; clip: rect(1px,1px,1px,1px); clip-path: inset(50%);
  height: 1px; margin: -1px; overflow: hidden; padding: 0;
  position: absolute; width: 1px; word-wrap: normal;
}

/* ---------------- Header ---------------- */
header.site {
  position: sticky; top: 0; z-index: 50;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.header-in { display: flex; align-items: center; gap: 20px; min-height: 68px; }
.brand { display: flex; align-items: center; gap: 11px; flex: none; }
.brand:hover { text-decoration: none; }
.mark {
  width: 38px; height: 38px; border-radius: 8px;
  background: var(--mark-bg);
  display: grid; place-items: center;
  position: relative; flex: none;
}
.mark .i {
  font-family: "Source Serif 4", Georgia, serif;
  font-style: italic; font-weight: 700;
  color: #fff; font-size: 24px; line-height: 1;
  transform: translateY(1px);
}
.mark .dot {
  position: absolute; width: 7px; height: 7px; border-radius: 50%;
  background: var(--amber-bright);
  top: 6px; left: 50%; transform: translateX(-2.5px);
}
.wordmark {
  font-family: "Source Serif 4", Georgia, serif;
  font-weight: 700; font-size: 24px; letter-spacing: -.01em; color: var(--ink);
}
.wordmark .tld { color: var(--amber); }
nav.main { display: flex; gap: 4px; margin-left: auto; }
nav.main a {
  color: var(--ink-soft); font-weight: 600; font-size: 15.5px;
  padding: 8px 12px; border-radius: 7px;
}
nav.main a:hover { color: var(--ink); background: var(--surface-2); text-decoration: none; }
.header-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }
nav.main + .header-actions { margin-left: 0; }
.theme-toggle {
  display: grid; place-items: center; flex: none;
  width: 38px; height: 38px; border-radius: 999px;
  border: 1px solid var(--line-strong); background: var(--surface);
  color: var(--ink-soft); cursor: pointer;
}
.theme-toggle:hover { border-color: var(--amber); color: var(--amber); }
.theme-toggle .moon { display: none; }
[data-theme="dark"] .theme-toggle .sun { display: none; }
[data-theme="dark"] .theme-toggle .moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .sun { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .moon { display: block; }
}
.header-search {
  display: flex; align-items: center; gap: 8px; flex: none;
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 7px 14px; background: var(--surface);
  color: var(--ink-faint); font-size: 15px; cursor: pointer;
  font-family: inherit;
}
.header-search:hover { border-color: var(--amber); color: var(--ink-soft); }
.header-search svg { flex: none; }
.menu-btn {
  display: none; flex: none;
  background: none; border: 1px solid var(--line-strong);
  border-radius: 8px; padding: 8px 10px; cursor: pointer; color: var(--ink);
}
.mobile-nav { display: none; border-top: 1px solid var(--line); padding: 10px 24px 16px; }
.mobile-nav.open { display: block; }
.mobile-nav a { display: block; padding: 9px 4px; font-weight: 600; color: var(--ink-soft); border-bottom: 1px solid var(--line); }
.mobile-nav a:last-child { border-bottom: none; }

/* ---------------- Hero ---------------- */
.hero {
  text-align: center;
  padding: 72px 0 60px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.hero .over {
  font-size: 13px; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--amber);
}
.hero h1 {
  font-family: "Source Serif 4", Georgia, serif;
  font-weight: 700; letter-spacing: -.015em;
  font-size: clamp(36px, 5.4vw, 56px); line-height: 1.12;
  max-width: 760px; margin: 16px auto 0;
}
.hero .tag { max-width: 640px; margin: 18px auto 0; font-size: 19px; color: var(--ink-soft); }
.searchbox { max-width: 620px; margin: 34px auto 0; position: relative; text-align: left; }
.search-row {
  display: flex; gap: 0;
  background: var(--surface);
  border: 1.5px solid var(--navy);
  border-radius: 12px; overflow: hidden;
  box-shadow: var(--shadow);
}
.search-row svg { align-self: center; margin-left: 16px; flex: none; color: var(--ink-faint); }
.search-row input {
  flex: 1; min-width: 0; border: none; outline: none; background: transparent;
  font: inherit; font-size: 17px; color: var(--ink);
  padding: 15px 12px;
}
.search-row input::placeholder { color: var(--ink-faint); }
.search-row button {
  border: none; cursor: pointer; flex: none;
  background: var(--btn-bg); color: #fff;
  font: inherit; font-weight: 700; font-size: 16px;
  padding: 0 26px;
}
.search-row button:hover { background: var(--amber-bright); }
.suggest {
  position: absolute; left: 0; right: 0; top: calc(100% + 8px);
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 10px; box-shadow: var(--shadow);
  overflow: hidden; display: none; z-index: 20;
}
.suggest.open { display: block; }
.suggest button {
  display: flex; width: 100%; align-items: baseline; gap: 10px;
  background: none; border: none; cursor: pointer; text-align: left;
  padding: 11px 16px; font: inherit; font-size: 15.5px; color: var(--ink);
  border-bottom: 1px solid var(--line);
}
.suggest button:last-child { border-bottom: none; }
.suggest button:hover, .suggest button:focus-visible { background: var(--surface-2); }
.suggest .field { margin-left: auto; font-size: 12.5px; font-weight: 700; color: var(--amber); text-transform: uppercase; letter-spacing: .06em; flex: none; }
.popular { margin-top: 18px; font-size: 15px; color: var(--ink-faint); }
.popular a { font-weight: 600; margin: 0 2px; }
.hero-stats { display: flex; justify-content: center; gap: 0; flex-wrap: wrap; margin-top: 44px; }
.hero-stats div { padding: 0 26px; border-left: 1px solid var(--line); }
.hero-stats div:first-child { border-left: none; }
.hero-stats b {
  display: block; font-family: "Source Serif 4", Georgia, serif;
  font-size: 26px; font-weight: 700; color: var(--ink);
}
.hero-stats span { font-size: 13.5px; color: var(--ink-faint); }

/* ---------------- Sections / vertical cards ---------------- */
section.block { padding: 64px 0; }
.sec-head { max-width: 680px; margin-bottom: 34px; }
.sec-head .phase {
  display: inline-block; font-size: 12.5px; font-weight: 700;
  letter-spacing: .1em; text-transform: uppercase;
  color: var(--amber); border: 1px solid var(--amber);
  padding: 4px 11px; border-radius: 999px; margin-bottom: 14px;
}
.sec-head h2 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(27px, 3.4vw, 36px); font-weight: 700; letter-spacing: -.01em; line-height: 1.2;
}
.sec-head p { margin-top: 10px; color: var(--ink-soft); font-size: 17.5px; }

.grid4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.vcard {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden;
  display: flex; flex-direction: column;
  transition: border-color .18s ease, box-shadow .18s ease;
}
.vcard:hover { border-color: var(--line-strong); box-shadow: var(--shadow); }
.vcard .photo { aspect-ratio: 16 / 10; overflow: hidden; background: var(--surface-2); }
.vcard .photo img { width: 100%; height: 100%; object-fit: cover; }
.vcard .body { padding: 20px 20px 22px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.vcard .title-row { display: flex; align-items: center; gap: 10px; }
.vicon {
  width: 34px; height: 34px; border-radius: 8px; flex: none;
  background: var(--amber-soft); color: var(--amber);
  display: grid; place-items: center;
}
.vcard h3 { font-family: "Source Serif 4", Georgia, serif; font-size: 20px; font-weight: 700; line-height: 1.25; }
.vcard h3 a { color: var(--ink); }
.vcard h3 a:hover { color: var(--amber); text-decoration: none; }
.vcard p { color: var(--ink-soft); font-size: 15.5px; }
.vcard .samples { margin-top: 2px; border-top: 1px solid var(--line); padding-top: 12px; list-style: none; }
.vcard .samples li { font-size: 14.5px; padding: 3px 0; color: var(--ink-soft); }
.vcard .samples li::before { content: "—"; color: var(--amber); margin-right: 8px; }
.vcard .go { margin-top: auto; padding-top: 12px; font-weight: 700; font-size: 15px; }
.vcard .go a { color: var(--amber); }

/* ---------------- Featured guide ---------------- */
.featured-sec { background: var(--surface-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.featured {
  display: grid; grid-template-columns: 1fr 1.15fr;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 14px; overflow: hidden; box-shadow: var(--shadow);
}
.featured .photo { min-height: 100%; background: var(--surface-2); }
.featured .photo img { width: 100%; height: 100%; object-fit: cover; }
.featured .body { padding: 34px 36px 30px; }
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; font-weight: 700; letter-spacing: .05em; text-transform: uppercase;
  padding: 4px 10px; border-radius: 999px; white-space: nowrap;
}
.badge.t1 { background: var(--teal-soft); color: var(--teal); }
.badge.t2 { background: var(--amber-soft); color: var(--amber); }
.badge.field { background: var(--surface-2); color: var(--ink-soft); border: 1px solid var(--line); }
.featured h3 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(25px, 3vw, 33px); font-weight: 700; line-height: 1.22; letter-spacing: -.01em;
  margin-top: 14px;
}
.featured h3 a { color: var(--ink); }
.featured h3 a:hover { color: var(--amber); text-decoration: none; }
.featured .lede { margin-top: 12px; color: var(--ink-soft); font-size: 17px; }
.stat-row { display: flex; gap: 26px; flex-wrap: wrap; margin-top: 20px; padding: 16px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.stat-row b { display: block; font-family: "Source Serif 4", Georgia, serif; font-size: 23px; color: var(--ink); }
.stat-row span { font-size: 13px; color: var(--ink-faint); }
.tier-rows { margin-top: 20px; display: grid; gap: 12px; }
.tier-row {
  display: flex; gap: 14px; align-items: flex-start;
  border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px;
}
.tier-row .txt b { display: block; font-size: 16px; }
.tier-row .txt span { font-size: 14.5px; color: var(--ink-soft); }
.tier-row .meta { margin-left: auto; flex: none; text-align: right; font-size: 13px; color: var(--ink-faint); }
.tier-row .meta b { display: block; font-size: 15px; color: var(--ink); font-family: "IBM Plex Mono", monospace; font-weight: 500; }
.featured .actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 22px; }
.btn {
  display: inline-block; font-weight: 700; font-size: 15.5px;
  padding: 11px 20px; border-radius: 9px; cursor: pointer; border: 1px solid transparent;
  font-family: inherit;
}
.btn:hover { text-decoration: none; }
.btn.primary { background: var(--btn-bg); color: #fff; }
.btn.primary:hover { background: var(--amber-bright); }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn.ghost:hover { border-color: var(--amber); color: var(--amber); }
.src-note { margin-top: 16px; font-size: 13.5px; color: var(--ink-faint); }

.anatomy { margin-top: 28px; }
.anatomy h4 { font-size: 13px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--ink-faint); margin: 0 0 12px; }
.anatomy ol { margin: 0; padding: 0; list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.anatomy li {
  background: var(--surface); border: 1px solid var(--line); border-radius: 999px;
  padding: 7px 14px 7px 9px; font-size: 14.5px; font-weight: 600; color: var(--ink-soft);
  display: flex; align-items: center; gap: 9px;
}
.anatomy li i {
  font-style: normal; width: 21px; height: 21px; border-radius: 50%;
  background: var(--btn-bg); color: #fff; font-size: 12px; font-weight: 700;
  display: grid; place-items: center; flex: none;
}

/* ---------------- Two depths ---------------- */
.depths { display: grid; grid-template-columns: .9fr 1.4fr; gap: 44px; align-items: start; }
.depths .copy h2 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(27px, 3.4vw, 36px); font-weight: 700; line-height: 1.2; letter-spacing: -.01em;
}
.depths .copy p { margin-top: 14px; color: var(--ink-soft); font-size: 17.5px; }
.depths .copy p b { color: var(--ink); }
.toggle {
  display: inline-flex; margin-top: 24px;
  border: 1px solid var(--line-strong); border-radius: 999px; padding: 4px;
  background: var(--surface);
}
.toggle button {
  border: none; background: transparent; cursor: pointer; font: inherit;
  font-weight: 700; font-size: 15px; color: var(--ink-soft);
  padding: 9px 20px; border-radius: 999px;
  display: inline-flex; align-items: center; gap: 8px;
}
.toggle button .dotp { width: 8px; height: 8px; border-radius: 50%; background: currentColor; opacity: .45; }
.toggle button[aria-selected="true"] { background: var(--btn-bg); color: #fff; }
.toggle button[aria-selected="true"] .dotp { opacity: 1; }
.toggle a.tier-link { display: inline-flex; }
.panel {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 14px; box-shadow: var(--shadow);
  overflow: hidden;
}
.panel-head {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 18px 24px; border-bottom: 1px solid var(--line);
  background: var(--surface-2);
}
.panel-head .topic { font-family: "Source Serif 4", Georgia, serif; font-weight: 700; font-size: 19px; }
.panel-head .who { margin-left: auto; font-size: 13.5px; color: var(--ink-faint); }
.panel-body { padding: 24px; }
.panel-body h5 { margin: 0 0 10px; font-family: "Source Serif 4", Georgia, serif; font-size: 20px; font-weight: 700; }
.panel-body p { color: var(--ink-soft); font-size: 16.5px; }
.panel-body p + p { margin-top: 12px; }
.panel-body .gene { font-family: "IBM Plex Mono", monospace; font-style: italic; font-size: .92em; color: var(--ink); }
.get-list { margin-top: 18px; display: grid; gap: 8px; list-style: none; }
.get-list li { display: flex; gap: 10px; font-size: 15.5px; color: var(--ink-soft); }
.get-list li svg { flex: none; margin-top: 3px; color: var(--teal); }
.chart-box { margin-top: 20px; border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px 10px; }
.chart-box h6 { margin: 0 0 4px; font-size: 13px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-faint); }
.chart-box .cap { font-size: 13px; color: var(--ink-faint); margin-top: 6px; }
table.lit, table.lit-table { width: 100%; border-collapse: collapse; margin-top: 20px; font-size: 14.5px; }
table.lit caption, table.lit-table caption { text-align: left; font-size: 13px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-faint); padding-bottom: 8px; }
table.lit th, table.lit td, table.lit-table th, table.lit-table td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.lit th, table.lit-table th { font-size: 12.5px; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-faint); }
table.lit td, table.lit-table td { color: var(--ink-soft); }
table.lit td:first-child, table.lit-table td:first-child { color: var(--ink); font-weight: 600; }
.panel-foot { padding: 16px 24px; border-top: 1px solid var(--line); display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.panel-foot .switch-note { font-size: 14px; color: var(--ink-faint); margin-left: auto; }

/* ---------------- Phase 2 ---------------- */
.phase2-sec { border-top: 1px solid var(--line); }
.grid6 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.soon {
  border: 1px dashed var(--line-strong); border-radius: var(--radius);
  padding: 20px 18px; background: transparent;
}
.soon .vicon { background: var(--surface-2); color: var(--ink-faint); margin-bottom: 12px; }
.soon h3 { font-family: "Source Serif 4", Georgia, serif; font-size: 18.5px; font-weight: 700; }
.soon p { font-size: 14.5px; color: var(--ink-faint); margin-top: 6px; }
.soon .chip {
  display: inline-block; margin-top: 14px; font-size: 11.5px; font-weight: 700;
  letter-spacing: .08em; text-transform: uppercase; color: var(--amber);
  border: 1px solid var(--amber); border-radius: 999px; padding: 3px 10px;
}

/* ---------------- Footer ---------------- */
footer.site { background: var(--footer-bg); color: #c7d3e0; padding: 56px 0 0; }
footer .wordmark { color: #fff; }
footer .blurb { margin-top: 14px; font-size: 15px; color: #9db0c3; max-width: 300px; }
.foot-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 36px; padding-bottom: 44px; }
footer h4 { margin: 0 0 14px; font-size: 13px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: #fff; }
footer ul { list-style: none; }
footer li { padding: 4px 0; }
footer a { color: #c7d3e0; font-size: 15px; }
footer a:hover { color: #fff; }
.foot-base {
  border-top: 1px solid rgba(255,255,255,.14);
  padding: 20px 0 26px; display: flex; gap: 16px; flex-wrap: wrap;
  font-size: 14px; color: #8fa3b8;
}
.foot-base .right { margin-left: auto; }

/* ---------------- Guide article (single-guide) ---------------- */
.guide-hero {
  padding: 56px 0 8px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.guide-hero .badges { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.guide-hero h1 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(30px, 4.4vw, 46px); font-weight: 700;
  letter-spacing: -.015em; line-height: 1.16; max-width: 860px;
}
.guide-hero .lede { margin-top: 14px; font-size: 19.5px; color: var(--ink-soft); max-width: 720px; }
.guide-meta {
  display: flex; gap: 18px; flex-wrap: wrap; align-items: center;
  margin-top: 20px; padding-bottom: 26px;
  font-size: 14px; color: var(--ink-faint);
}
.guide-meta .byline { font-weight: 700; color: var(--ink-soft); }
.tier-switch {
  display: flex; gap: 0; margin: 26px 0 0;
  border: 1px solid var(--line-strong); border-radius: 12px; padding: 4px;
  background: var(--surface); max-width: 640px;
}
.tier-switch a {
  flex: 1; text-align: center; border-radius: 9px;
  padding: 11px 14px; font-weight: 700; font-size: 15px; color: var(--ink-soft);
  display: flex; align-items: center; justify-content: center; gap: 8px;
}
.tier-switch a:hover { text-decoration: none; color: var(--ink); }
.tier-switch a.current { background: var(--btn-bg); color: #fff; pointer-events: none; }
.tier-switch a .dotp { width: 8px; height: 8px; border-radius: 50%; background: currentColor; opacity: .45; }
.tier-switch a.current .dotp { opacity: 1; }

.guide-layout { display: grid; grid-template-columns: 1fr 300px; gap: 48px; padding: 40px 0 64px; align-items: start; }
.guide-body { font-size: 18px; line-height: 1.7; color: var(--ink); min-width: 0; }
.guide-body > * + * { margin-top: 1.25em; }
.guide-body h2 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(24px, 3vw, 31px); font-weight: 700; letter-spacing: -.01em; line-height: 1.25;
  margin-top: 2em; padding-top: .4em; border-top: 1px solid var(--line);
}
.guide-body h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
.guide-body h3 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 21px; font-weight: 700; margin-top: 1.6em;
}
.guide-body p { color: var(--ink); }
.guide-body ul, .guide-body ol { padding-left: 1.4em; }
.guide-body li { margin: .4em 0; }
.guide-body li::marker { color: var(--amber); font-weight: 700; }
.guide-body a { color: var(--navy); text-decoration: underline; text-decoration-color: var(--amber); text-underline-offset: 3px; }
.guide-body a:hover { color: var(--amber); }
.guide-body strong { color: var(--ink); }
.guide-body code {
  font-family: "IBM Plex Mono", monospace; font-size: .86em;
  background: var(--surface-2); border: 1px solid var(--line);
  border-radius: 5px; padding: 1px 6px;
}
.guide-body .gene, .guide-body em.gene {
  font-family: "IBM Plex Mono", monospace; font-style: italic; font-size: .92em;
}
figure.guide-chart {
  margin: 2em 0; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); padding: 18px 18px 12px; box-shadow: var(--shadow);
}
figure.guide-chart img { border-radius: 6px; }
figure.guide-chart figcaption { font-size: 14px; color: var(--ink-faint); margin-top: 10px; line-height: 1.5; }
ol.references { padding-left: 1.6em; font-size: 15.5px; color: var(--ink-soft); }
ol.references li { margin: .55em 0; padding-left: .3em; }
ol.references a { word-break: break-all; }
.medical-disclaimer {
  border: 1.5px solid var(--amber); border-radius: var(--radius);
  background: var(--amber-soft); padding: 18px 20px; margin: 2em 0;
  font-size: 15.5px; color: var(--ink-soft);
}
.medical-disclaimer strong { display: block; color: var(--amber); font-size: 13px; letter-spacing: .08em; text-transform: uppercase; margin-bottom: 8px; }
.prerequisites-box {
  border: 1px solid var(--line-strong); border-radius: var(--radius);
  background: var(--surface-2); padding: 18px 20px; margin: 0 0 2em;
  font-size: 15.5px; color: var(--ink-soft);
}
.prerequisites-box strong { color: var(--ink); }
.faq-section { margin-top: 2em; }
.faq-section > h2, .faq-section > h3:first-child { margin-bottom: .6em; }
.faq-q { font-family: "Source Serif 4", Georgia, serif; font-size: 20px !important; font-weight: 700; margin-top: 1.4em !important; }
.faq-a { color: var(--ink-soft); }
p.chart-credit { font-size: 13.5px; color: var(--ink-faint); font-style: italic; }
.paired-cta {
  margin-top: 3em; border: 1px solid var(--line); border-radius: 14px;
  background: var(--surface); box-shadow: var(--shadow);
  padding: 26px 28px; display: flex; gap: 20px; align-items: center; flex-wrap: wrap;
}
.paired-cta .txt { flex: 1; min-width: 220px; }
.paired-cta .txt b { font-family: "Source Serif 4", Georgia, serif; font-size: 20px; display: block; margin-bottom: 6px; }
.paired-cta .txt span { color: var(--ink-soft); font-size: 15.5px; }

/* Table of contents sidebar */
.guide-toc {
  position: sticky; top: 92px;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); padding: 20px 20px 14px; font-size: 14.5px;
}
.guide-toc h4 { font-size: 12px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--ink-faint); margin: 0 0 10px; }
.guide-toc ol { list-style: none; }
.guide-toc li { padding: 5px 0; border-bottom: 1px solid var(--line); }
.guide-toc li:last-child { border-bottom: none; }
.guide-toc a { color: var(--ink-soft); }
.guide-toc a:hover { color: var(--amber); text-decoration: none; }
.guide-toc .toc-tier { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--line); }

/* ---------------- Archives / search / pages ---------------- */
.archive-hero { padding: 56px 0 34px; border-bottom: 1px solid var(--line); background: var(--surface); }
.archive-hero .badges { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.archive-hero h1 { font-family: "Source Serif 4", Georgia, serif; font-size: clamp(30px, 4.4vw, 44px); font-weight: 700; letter-spacing: -.015em; }
.archive-hero p { margin-top: 12px; color: var(--ink-soft); font-size: 18px; max-width: 720px; }
.guide-list { display: grid; gap: 18px; padding: 36px 0 64px; }
.guide-card {
  display: grid; grid-template-columns: 220px 1fr;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 14px; overflow: hidden; box-shadow: var(--shadow);
}
.guide-card .photo { min-height: 170px; background: var(--surface-2); }
.guide-card .photo img { width: 100%; height: 100%; object-fit: cover; }
.guide-card .body { padding: 22px 24px; }
.guide-card .badges { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 10px; }
.guide-card h2 { font-family: "Source Serif 4", Georgia, serif; font-size: 23px; font-weight: 700; line-height: 1.3; }
.guide-card h2 a { color: var(--ink); }
.guide-card h2 a:hover { color: var(--amber); text-decoration: none; }
.guide-card .lede { margin-top: 8px; color: var(--ink-soft); font-size: 15.5px; }
.guide-card .meta { margin-top: 12px; font-size: 13.5px; color: var(--ink-faint); display: flex; gap: 14px; flex-wrap: wrap; }
.empty-state { padding: 60px 0; text-align: center; color: var(--ink-soft); }
.empty-state h2 { font-family: "Source Serif 4", Georgia, serif; font-size: 28px; color: var(--ink); margin-bottom: 10px; }

.page-hero { padding: 52px 0 10px; }
.page-hero h1 { font-family: "Source Serif 4", Georgia, serif; font-size: clamp(30px, 4.4vw, 42px); font-weight: 700; letter-spacing: -.015em; }
.page-body { max-width: 760px; padding: 26px 0 70px; font-size: 18px; line-height: 1.7; }
.page-body > * + * { margin-top: 1.2em; }
.page-body h2 { font-family: "Source Serif 4", Georgia, serif; font-size: 26px; font-weight: 700; margin-top: 1.8em; }
.page-body h3 { font-family: "Source Serif 4", Georgia, serif; font-size: 21px; font-weight: 700; margin-top: 1.5em; }
.page-body ul, .page-body ol { padding-left: 1.4em; }
.page-body li { margin: .4em 0; }
.page-body a { color: var(--navy); text-decoration: underline; text-decoration-color: var(--amber); text-underline-offset: 3px; }

.search-results-meta { color: var(--ink-faint); font-size: 15px; margin-top: 10px; }
.pagination { display: flex; gap: 8px; justify-content: center; padding: 10px 0 60px; }
.pagination a, .pagination span {
  border: 1px solid var(--line-strong); border-radius: 8px; padding: 8px 14px;
  font-weight: 600; font-size: 15px; color: var(--ink-soft); background: var(--surface);
}
.pagination a:hover { border-color: var(--amber); color: var(--amber); text-decoration: none; }
.pagination .current { background: var(--btn-bg); color: #fff; border-color: var(--btn-bg); }

/* ---------------- Responsive ---------------- */
@media (max-width: 1020px) {
  .grid4 { grid-template-columns: repeat(2, 1fr); }
  .grid6 { grid-template-columns: repeat(2, 1fr); }
  .depths { grid-template-columns: 1fr; gap: 28px; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .guide-layout { grid-template-columns: 1fr; }
  .guide-toc { position: static; }
}
@media (max-width: 760px) {
  nav.main { display: none; }
  .header-search { display: none; }
  .header-actions { margin-left: auto; }
  nav.main + .header-actions { margin-left: auto; }
  .menu-btn { display: block; }
  .hero { padding: 48px 0 44px; }
  .hero-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 22px 0; }
  .hero-stats div { padding: 0 10px; border-left: none; }
  .hero-stats b { font-size: 21px; }
  .featured { grid-template-columns: 1fr; }
  .featured .photo { aspect-ratio: 16 / 9; }
  .featured .body { padding: 24px 22px; }
  section.block { padding: 46px 0; }
  .search-row button { padding: 0 18px; }
  .guide-card { grid-template-columns: 1fr; }
  .guide-card .photo { aspect-ratio: 16 / 9; min-height: 0; }
  .tier-switch { flex-direction: column; }
}
@media (max-width: 560px) {
  .grid4 { grid-template-columns: 1fr; }
  .grid6 { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr; }
  .tier-row { flex-wrap: wrap; }
  .tier-row .meta { margin-left: 0; text-align: left; }
  table.lit th:nth-child(3), table.lit td:nth-child(3),
  table.lit-table th:nth-child(3), table.lit-table td:nth-child(3) { display: none; }
  .guide-body { font-size: 17px; }
}