:host {
  --ink: #192321;
  --muted: #596562;
  --paper: #f6f1e7;
  --panel: #fffdf8;
  --teal: #235d59;
  --teal-soft: #dcebe7;
  --rust: #b44d32;
  --gold: #d5a447;
  --line: #d8d0c2;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
.academy-book-content { min-height: 100%; margin: 0; color: var(--ink); background: var(--paper); font-family: var(--serif); font-size: 18px; line-height: 1.75; }
.reader-section-content { padding: clamp(36px, 5vw, 58px) clamp(32px, 5vw, 52px) clamp(58px, 8vw, 92px); }
.reader-section-content > .major-section { width: min(780px, 100%); margin: 0 auto; }
.reader-introduction-content .book-shell { width: min(780px, calc(100% - 96px)); }
a { color: var(--teal); text-underline-offset: .18em; }
a:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; }
.skip-link { position: fixed; z-index: 20; top: 12px; left: 16px; padding: 10px 14px; color: #fff; background: var(--ink); font-family: var(--sans); font-size: .8rem; font-weight: 750; text-decoration: none; transform: translateY(-180%); transition: transform .15s ease; }
.skip-link:focus { transform: translateY(0); }
.book-shell { width: min(780px, calc(100% - 34px)); margin: 0 auto; }
.chapter-hero { padding: 72px 0 58px; color: #fffaf2; background: linear-gradient(135deg, #172e2c, var(--teal)); }
.chapter-label, .section-number, .feature-label { font-family: var(--sans); font-size: .72rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.chapter-label { color: var(--gold); }
h1, h2, h3 { font-family: var(--serif); line-height: 1.14; }
h1 { max-width: 780px; margin: 12px 0 18px; font-size: clamp(2.8rem, 8vw, 5.5rem); font-weight: 500; letter-spacing: -.045em; }
.chapter-promise { max-width: 720px; margin: 0; color: rgba(255,255,255,.82); font-size: 1.28rem; }
.chapter-nav { position: sticky; z-index: 5; top: 0; background: rgba(246,241,231,.95); border-bottom: 1px solid var(--line); backdrop-filter: blur(10px); }
.chapter-nav .book-shell { display: flex; justify-content: space-between; gap: 16px; padding-block: 10px; font-family: var(--sans); font-size: .72rem; font-weight: 750; }
main.book-shell { padding-block: 55px 90px; }
.opening { color: #253432; font-size: 1.18rem; }
.opening::first-letter { float: left; margin: .12em .1em 0 0; color: var(--rust); font-size: 4.4rem; line-height: .73; }
.chapter-roadmap { margin: 42px 0 58px; padding: 24px 26px; background: var(--panel); border: 1px solid var(--line); border-top: 5px solid var(--gold); }
.chapter-roadmap h2 { margin: 0 0 15px; font-family: var(--sans); font-size: .82rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.chapter-roadmap ol { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 24px; margin: 0; padding: 0; list-style: none; }
.chapter-roadmap a { display: grid; grid-template-columns: 82px 1fr; gap: 8px; align-items: baseline; padding: 6px 0; color: var(--ink); font-family: var(--sans); font-size: .82rem; line-height: 1.35; text-decoration: none; border-bottom: 1px solid var(--line); }
.chapter-roadmap a:hover { color: var(--teal); }
.chapter-roadmap a span { color: var(--rust); font-size: .68rem; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; }
.major-section { margin-top: 70px; scroll-margin-top: 65px; }
.section-number { display: block; margin-bottom: 8px; color: var(--rust); }
h2 { margin: 0 0 22px; font-size: clamp(2rem, 5vw, 3.15rem); font-weight: 500; letter-spacing: -.025em; }
h3 { font-size: 1.45rem; }
figure { margin: 40px 0 44px; }
figure img { display: block; width: 100%; height: auto; background: #fff; border: 1px solid var(--line); box-shadow: 0 16px 42px rgba(38,48,45,.11); }
figcaption { margin-top: 12px; color: var(--muted); font-family: var(--sans); font-size: .83rem; line-height: 1.5; }
figcaption strong { color: var(--ink); }
.audio-description { margin-top: 9px; color: var(--muted); font-family: var(--sans); font-size: .79rem; }
.audio-description summary { cursor: pointer; color: var(--teal); font-weight: 750; }
.audio-description p { margin: 8px 0 0; }
.feature { margin: 34px 0; padding: 24px 27px; background: var(--panel); border: 1px solid var(--line); border-left: 5px solid var(--teal); }
.feature.hype { border-left-color: var(--rust); }
.feature.decision { border-left-color: var(--gold); }
.feature-label { color: var(--teal); }
.feature.hype .feature-label { color: var(--rust); }
.feature.decision .feature-label { color: #856215; }
.feature h3 { margin: 7px 0 8px; }
.feature p, .feature ul { margin-block: 8px 0; }
.analogy-break { margin: 28px 0; padding: 18px 22px; color: var(--muted); background: var(--teal-soft); border-radius: 3px; }
.analogy-break strong { color: var(--ink); }
.key-terms { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; margin: 25px 0; padding: 0; list-style: none; }
.key-terms li { padding: 12px 8px; background: var(--teal-soft); font-family: var(--sans); font-size: .78rem; font-weight: 750; text-align: center; }
.reflection li { margin-bottom: 12px; }
.sources { padding-left: 1.25em; font-family: var(--sans); font-size: .82rem; }
.sources li { margin-bottom: 10px; }
.chapter-footer { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 65px; padding-top: 25px; border-top: 1px solid var(--line); font-family: var(--sans); font-size: .8rem; }
.chapter-footer a { padding: 16px; background: var(--panel); border: 1px solid var(--line); text-decoration: none; }
.chapter-footer .next { text-align: right; }
.book-toc { display: grid; gap: 12px; padding: 35px 0 80px; }
.toc-item { display: grid; grid-template-columns: 60px 1fr; gap: 15px; padding: 20px; color: inherit; background: var(--panel); border: 1px solid var(--line); text-decoration: none; }
.toc-item[aria-disabled="true"] { opacity: .55; }
.toc-item strong { font-family: var(--sans); color: var(--rust); }
.toc-item span { font-size: 1.08rem; }
.compact-hero { padding-block: 54px 42px; }
.compact-hero h1 { font-size: clamp(2.5rem, 7vw, 4.6rem); }
.publication-matter { min-height: 65vh; }
.publication-matter > h2 { margin-top: 54px; }
.title-page-details, .metadata-note { color: var(--muted); font-family: var(--sans); }
.publication-links { margin: 54px 0 38px; padding: 28px; background: var(--panel); border: 1px solid var(--line); border-top: 5px solid var(--gold); }
.publication-links div { display: flex; flex-wrap: wrap; gap: 10px; }
.publication-links a { padding: 9px 12px; background: var(--teal-soft); font-family: var(--sans); font-size: .78rem; font-weight: 750; text-decoration: none; }
.glossary-list > div { display: grid; grid-template-columns: minmax(150px, 1fr) 3fr; gap: 24px; padding: 20px 0; border-bottom: 1px solid var(--line); }
.glossary-list dt { font-family: var(--sans); font-weight: 800; }
.glossary-list dd { margin: 0; }
.book-timeline { padding: 0; list-style: none; }
.book-timeline li { display: grid; grid-template-columns: 95px 1fr; gap: 20px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.book-timeline li > span { color: var(--rust); font-family: var(--sans); font-weight: 850; }
.production-checklist { padding: 0; list-style: none; }
.production-checklist li { position: relative; margin: 10px 0; padding: 12px 14px 12px 44px; background: var(--panel); border: 1px solid var(--line); }
.production-checklist li::before { position: absolute; left: 15px; top: 12px; content: "□"; color: var(--teal); font-family: var(--sans); font-weight: 900; }
.endnote-chapter { margin-top: 60px; }
.endnote-chapter h2 { font-size: 1.8rem; }
.concept-index { display: grid; grid-template-columns: 1fr 1fr; gap: 0 24px; padding: 0; list-style: none; }
.concept-index li { display: flex; justify-content: space-between; gap: 12px; padding: 9px 0; border-bottom: 1px solid var(--line); }
.concept-index strong { font-family: var(--sans); font-size: .82rem; }
.concept-index span { white-space: nowrap; }
.combined-front { min-height: 100vh; padding: 18vh 0 60px; color: #fffaf2; background: linear-gradient(135deg, #172e2c, var(--teal)); }
.combined-front .metadata-note { margin-top: 56px; color: rgba(255,255,255,.68); }
.combined-contents, .combined-matter, .combined-back { padding-block: 70px; }
.combined-matter { border-top: 2px solid var(--line); }
.combined-contents ol { display: grid; grid-template-columns: 1fr 1fr; gap: 0 28px; padding: 0; list-style: none; }
.combined-contents li { border-bottom: 1px solid var(--line); }
.combined-contents a { display: grid; grid-template-columns: 48px 1fr; gap: 10px; padding: 11px 0; color: var(--ink); font-family: var(--sans); font-size: .82rem; line-height: 1.35; text-decoration: none; }
.combined-contents a span { color: var(--rust); font-weight: 800; }
.combined-main { padding-block: 55px 90px; }
.combined-back { border-top: 2px solid var(--line); }

/* Version 7 reading navigation */
.has-book-sidebar { padding-left: 300px; }
.book-sidebar {
  position: fixed;
  z-index: 40;
  inset: 0 auto 0 0;
  display: flex;
  flex-direction: column;
  width: 300px;
  color: #fffaf2;
  background: #172e2c;
  border-right: 1px solid rgba(255,255,255,.13);
  box-shadow: 12px 0 35px rgba(19,35,33,.12);
}
.book-sidebar-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding: 24px 22px 20px;
  border-bottom: 1px solid rgba(255,255,255,.14);
}
.book-sidebar-title { color: inherit; font-family: var(--sans); line-height: 1.3; text-decoration: none; }
.book-sidebar-title span { display: block; font-family: var(--serif); font-size: 1.14rem; }
.book-sidebar-title strong { display: block; margin-top: 5px; color: var(--gold); font-size: .65rem; letter-spacing: .13em; text-transform: uppercase; }
.book-sidebar nav { min-height: 0; overflow-y: auto; overscroll-behavior: contain; scrollbar-color: rgba(255,255,255,.24) transparent; }
.book-toc-heading { margin: 0; padding: 20px 22px 10px; color: rgba(255,255,255,.56); font-family: var(--sans); font-size: .65rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.book-sidebar-list { margin: 0; padding: 0 12px 18px; list-style: none; }
.book-sidebar-list li { margin: 1px 0; }
.book-toc-link {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 9px;
  align-items: start;
  padding: 8px 10px;
  color: rgba(255,255,255,.72);
  border-radius: 5px;
  font-family: var(--sans);
  font-size: .7rem;
  line-height: 1.35;
  text-decoration: none;
  transition: color .15s ease, background .15s ease, transform .15s ease;
}
.book-toc-link span { color: var(--gold); font-size: .64rem; font-variant-numeric: tabular-nums; letter-spacing: .04em; }
.book-toc-link strong { font-weight: 650; }
.book-toc-link:hover { color: #fff; background: rgba(255,255,255,.08); transform: translateX(2px); }
.book-toc-link[aria-current="true"] { color: #fff; background: rgba(213,164,71,.17); box-shadow: inset 3px 0 var(--gold); }
.book-sidebar-references { display: flex; flex-wrap: wrap; gap: 7px; margin: 0 12px 22px; padding: 18px 10px 0; border-top: 1px solid rgba(255,255,255,.12); font-family: var(--sans); }
.book-sidebar-references p { flex-basis: 100%; margin: 0 0 2px; color: rgba(255,255,255,.5); font-size: .62rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
.book-sidebar-references a { padding: 5px 8px; color: rgba(255,255,255,.72); border: 1px solid rgba(255,255,255,.17); border-radius: 3px; font-size: .65rem; text-decoration: none; }
.book-sidebar-references a:hover { color: #fff; border-color: var(--gold); }
.book-menu-close { display: none; }
.mobile-book-bar, .book-toc-backdrop { display: none; }
.book-menu-toggle, .book-menu-close {
  color: inherit;
  background: transparent;
  border: 0;
  font-family: var(--sans);
  font-weight: 750;
  cursor: pointer;
}
.book-menu-toggle svg, .book-menu-close svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; }
.book-menu-toggle:focus-visible, .book-menu-close:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; }

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.print-interactive-promo { display: none; }

/* Version 9 expanded knowledge drawers */
.knowledge-trigger {
  display: inline;
  margin: 0;
  padding: 0;
  color: inherit;
  background: transparent;
  border: 0;
  border-radius: 2px;
  font: inherit;
  line-height: inherit;
  text-align: inherit;
  text-decoration-line: underline;
  text-decoration-style: dotted;
  text-decoration-color: var(--teal);
  text-decoration-thickness: 1.5px;
  text-underline-offset: .19em;
  cursor: pointer;
}
.knowledge-trigger:hover, .knowledge-trigger[aria-expanded="true"] { color: var(--teal); background: var(--teal-soft); }
.knowledge-person-trigger { text-decoration-color: var(--rust); text-decoration-style: dashed; }
.knowledge-person-trigger:hover, .knowledge-person-trigger[aria-expanded="true"] { color: #8f3e29; background: #f3e3d9; }
.knowledge-drawer-backdrop {
  position: fixed;
  z-index: 89;
  inset: 0;
  width: 100%;
  height: 100%;
  padding: 0;
  background: rgba(13, 27, 25, .48);
  border: 0;
  opacity: 0;
  backdrop-filter: blur(2px);
  transition: opacity .24s ease;
}
.knowledge-drawer-backdrop[hidden], .knowledge-drawer[hidden] { display: none; }
.knowledge-drawer-backdrop.is-open { opacity: 1; }
.knowledge-drawer {
  position: fixed;
  z-index: 90;
  inset: 0 0 0 auto;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  width: min(650px, calc(100vw - 64px));
  color: var(--ink);
  background: #fffdf8;
  border-left: 6px solid var(--gold);
  box-shadow: -24px 0 70px rgba(14, 31, 29, .26);
  transform: translateX(104%);
  visibility: hidden;
  transition: transform .26s cubic-bezier(.22,.74,.22,1), visibility 0s linear .26s;
}
.knowledge-drawer.is-open { transform: translateX(0); visibility: visible; transition-delay: 0s; }
.knowledge-drawer-open { overflow: hidden; }
.knowledge-drawer-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  padding: 27px 30px 23px;
  background: #fffdf8;
  border-bottom: 1px solid var(--line);
}
.knowledge-drawer-kind { margin: 0 0 5px; color: var(--rust); font-family: var(--sans); font-size: .66rem; font-weight: 850; letter-spacing: .13em; line-height: 1.25; text-transform: uppercase; }
.knowledge-drawer h2 { margin: 0; font-size: clamp(1.75rem, 3.2vw, 2.5rem); letter-spacing: -.025em; }
.knowledge-drawer-close {
  flex: 0 0 auto;
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  padding: 0;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 50%;
  cursor: pointer;
}
.knowledge-drawer-close:hover { color: var(--ink); background: var(--teal-soft); }
.knowledge-drawer-close:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; }
.knowledge-drawer-close svg { width: 19px; height: 19px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; }
.knowledge-drawer-scroll { min-height: 0; padding: 28px 30px 50px; overflow-y: auto; overscroll-behavior: contain; scrollbar-color: var(--line) transparent; }
.knowledge-drawer-content { width: min(100%, 570px); margin: 0 auto; }
.academy-book-content.knowledge-drawer-surface { min-height: 0; background: transparent; }
.knowledge-lede { margin: 0 0 28px; color: #273633; font-size: 1.12rem; line-height: 1.62; }
.knowledge-section { padding: 25px 0 0; margin-top: 25px; border-top: 1px solid var(--line); }
.knowledge-section h3 { margin: 0 0 10px; color: var(--teal); font-family: var(--sans); font-size: .78rem; font-weight: 850; letter-spacing: .1em; line-height: 1.35; text-transform: uppercase; }
.knowledge-section p { margin: 0 0 13px; color: #384542; font-size: .98rem; line-height: 1.68; }
.knowledge-source-card .knowledge-section li { font-family: var(--sans); font-size: .82rem; line-height: 1.65; }
.knowledge-source-card .knowledge-section a { overflow-wrap: anywhere; }
.knowledge-links { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; padding-top: 24px; border-top: 1px solid var(--line); }
.knowledge-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 13px;
  color: var(--teal);
  background: var(--teal-soft);
  border-radius: 4px;
  font-family: var(--sans);
  font-size: .75rem;
  font-weight: 800;
  line-height: 1.35;
  text-decoration: none;
}
.knowledge-links a:hover { color: #fff; background: var(--teal); }
.knowledge-links svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.knowledge-source-note { margin: 22px 0 0; color: var(--muted); font-family: var(--sans); font-size: .69rem; line-height: 1.55; }
.knowledge-diagram { margin: 27px 0 34px; }
.knowledge-diagram svg { display: block; width: 100%; height: auto; color: var(--ink); background: #f7f2e9; border: 1px solid var(--line); border-radius: 7px; }
.knowledge-diagram figcaption { margin-top: 9px; color: var(--muted); font-size: .72rem; line-height: 1.45; }
.knowledge-diagram .kd-box rect { stroke-width: 1.5; }
.knowledge-diagram .kd-paper rect { fill: #fffdf8; stroke: #cfc6b7; }
.knowledge-diagram .kd-teal rect { fill: #dcebe7; stroke: #235d59; }
.knowledge-diagram .kd-gold rect { fill: #f5e5b9; stroke: #b98725; }
.knowledge-diagram .kd-rust rect { fill: #f2ddd5; stroke: #b44d32; }
.knowledge-diagram .kd-heading { fill: #192321; font: 700 15px var(--sans); text-anchor: middle; }
.knowledge-diagram .kd-detail { fill: #596562; font: 500 12px var(--sans); text-anchor: middle; }
.knowledge-diagram .kd-arrow, .knowledge-diagram .kd-path, .knowledge-diagram .kd-curve { fill: none; stroke: #65716e; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.knowledge-diagram .kd-arrow-head { fill: none; stroke: #65716e; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.knowledge-diagram .kd-axis { stroke: #9d978c; stroke-width: 1.5; }
.knowledge-diagram .kd-axis-label { fill: #596562; font: 500 12px var(--sans); text-anchor: middle; }
.knowledge-diagram .kd-cluster circle { stroke-width: 2; }
.knowledge-diagram .kd-cluster text { fill: #384542; font: 700 13px var(--sans); text-anchor: middle; }
.knowledge-diagram .kd-cluster.kd-teal circle { fill: #75a9a2; stroke: #235d59; }
.knowledge-diagram .kd-cluster.kd-gold circle { fill: #e6c777; stroke: #9d711c; }
.knowledge-diagram .kd-cluster.kd-rust circle { fill: #d78972; stroke: #9d3c27; }
.knowledge-diagram .kd-stop { fill: #fffdf8; stroke: #235d59; stroke-width: 2; }

/* Version 8 contextual reading aids */
.reading-note-ref { margin-inline: .08em; }
.reading-note-trigger {
  display: inline-grid;
  place-items: center;
  min-width: 1.45em;
  height: 1.45em;
  padding-inline: .28em;
  color: #fff;
  background: var(--teal);
  border-radius: 999px;
  font-family: var(--sans);
  font-size: .68em;
  font-weight: 800;
  line-height: 1;
  text-decoration: none;
  vertical-align: .2em;
}
.reading-note-trigger:hover, .reading-note-trigger[aria-expanded="true"] { background: var(--rust); }
.definition-trigger {
  color: inherit;
  text-decoration-line: underline;
  text-decoration-style: dotted;
  text-decoration-color: var(--teal);
  text-decoration-thickness: 1.5px;
  text-underline-offset: .19em;
}
.definition-trigger:hover, .definition-trigger[aria-expanded="true"] { color: var(--teal); background: var(--teal-soft); }
.reading-popover {
  position: fixed;
  z-index: 80;
  width: min(390px, calc(100vw - 32px));
  max-height: min(520px, calc(100vh - 32px));
  padding: 22px 23px 20px;
  overflow: auto;
  color: var(--ink);
  background: #fffdf8;
  border: 1px solid #c8bda9;
  border-top: 5px solid var(--gold);
  border-radius: 7px;
  box-shadow: 0 22px 58px rgba(18,35,33,.25), 0 4px 12px rgba(18,35,33,.12);
  opacity: 0;
  transform: translateY(5px) scale(.985);
  transition: opacity .14s ease, transform .14s ease;
}
.reading-popover[hidden] { display: none; }
.reading-popover.is-visible { opacity: 1; transform: none; }
.reading-popover-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; }
.reading-popover-kind { margin: 0 0 4px; color: var(--rust); font-family: var(--sans); font-size: .65rem; font-weight: 850; letter-spacing: .12em; line-height: 1.25; text-transform: uppercase; }
.reading-popover h2 { margin: 0; font-size: 1.42rem; letter-spacing: -.015em; }
.reading-popover-close { flex: 0 0 auto; display: inline-grid; place-items: center; width: 34px; height: 34px; padding: 0; color: var(--muted); background: transparent; border: 1px solid var(--line); border-radius: 50%; cursor: pointer; }
.reading-popover-close:hover { color: var(--ink); background: var(--teal-soft); }
.reading-popover-close svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; }
.reading-popover-body { margin: 15px 0 17px; color: #384542; font-size: .94rem; line-height: 1.58; }
.reading-popover-action { display: inline-flex; align-items: center; gap: 7px; color: var(--teal); font-family: var(--sans); font-size: .76rem; font-weight: 800; text-decoration: none; }
.reading-popover-action:hover { color: var(--rust); }
.reading-popover-action svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.reading-target-highlight { animation: reading-target-pulse 1.8s ease; scroll-margin-block: 35vh; }
@keyframes reading-target-pulse { 0%, 100% { background: transparent; } 20%, 72% { background: #f5dfad; } }

@media (max-width: 1040px) {
  .has-book-sidebar { padding-left: 0; }
  .mobile-book-bar {
    position: sticky;
    z-index: 35;
    top: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 58px;
    padding: 9px 16px;
    color: #fffaf2;
    background: rgba(23,46,44,.97);
    border-bottom: 1px solid rgba(255,255,255,.13);
    box-shadow: 0 5px 24px rgba(25,35,33,.16);
    backdrop-filter: blur(12px);
  }
  .mobile-book-bar > a { color: inherit; font-family: var(--serif); font-size: .92rem; text-decoration: none; }
  .book-menu-toggle { display: inline-flex; align-items: center; gap: 8px; padding: 5px 2px; font-size: .76rem; }
  .book-sidebar { width: min(86vw, 330px); transform: translateX(-105%); transition: transform .24s ease; }
  .book-menu-close { display: inline-flex; padding: 4px; color: rgba(255,255,255,.8); }
  .toc-open { overflow: hidden; }
  .toc-open .book-sidebar { transform: translateX(0); }
  .book-toc-backdrop { position: fixed; z-index: 39; inset: 0; display: block; width: 100%; height: 100%; padding: 0; background: rgba(10,20,19,.55); border: 0; backdrop-filter: blur(2px); }
  .book-toc-backdrop[hidden] { display: none; }
  .book-toc-link { padding-block: 9px; font-size: .76rem; }
}

@media (prefers-reduced-motion: reduce) {
  .book-sidebar, .book-toc-link, .reading-popover, .knowledge-drawer, .knowledge-drawer-backdrop { transition: none; }
  .reading-target-highlight { animation: none; background: #f5dfad; }
}

@media (max-width: 700px) {
  .knowledge-drawer { width: 100%; border-left: 0; border-top: 5px solid var(--gold); }
  .knowledge-drawer-header { padding: 19px 18px 16px; }
  .knowledge-drawer h2 { font-size: 1.7rem; }
  .knowledge-drawer-close { width: 38px; height: 38px; }
  .knowledge-drawer-scroll { padding: 22px 18px max(36px, env(safe-area-inset-bottom)); }
  .knowledge-lede { font-size: 1.03rem; }
  .knowledge-section p { font-size: .94rem; }
  .knowledge-diagram { margin-block: 23px 29px; }
}

@media (max-width: 700px) {
  .reading-popover {
    inset: auto 12px max(12px, env(safe-area-inset-bottom)) 12px;
    width: auto;
    max-height: min(68vh, 560px);
    padding: 20px 20px 18px;
    border-radius: 9px;
    transform: translateY(12px);
  }
  .reading-popover h2 { font-size: 1.3rem; }
  .reading-popover-body { font-size: .91rem; }
}

@media (max-width: 620px) {
  .academy-book-content { font-size: 17px; }
  .reader-section-content { padding: 32px 20px 56px; }
  .reader-introduction-content .book-shell { width: min(780px, calc(100% - 40px)); }
  .chapter-hero { padding-block: 48px 40px; }
  .key-terms { grid-template-columns: repeat(2, 1fr); }
  .chapter-roadmap ol { grid-template-columns: 1fr; }
  .chapter-footer { grid-template-columns: 1fr; }
  .chapter-footer .next { text-align: left; }
  .glossary-list > div { grid-template-columns: 1fr; gap: 6px; }
  .concept-index, .combined-contents ol { grid-template-columns: 1fr; }
}

@media print {
  @page { size: 6in 9in; margin: .68in .62in .72in; }
  .academy-book-content { color: #000; background: #fff; font-size: 10.5pt; line-height: 1.55; }
  .chapter-hero { min-height: 7.2in; break-after: page; padding: 1.4in .2in 0; background: #fff; color: #000; }
  .chapter-label { color: #000; }
  .chapter-promise { color: #333; }
  .skip-link, .chapter-nav, .chapter-roadmap, .audio-description, .chapter-footer, .book-sidebar, .mobile-book-bar, .book-toc-backdrop, .reading-popover, .knowledge-drawer, .knowledge-drawer-backdrop, template { display: none; }
  .definition-trigger { color: inherit; text-decoration: none; }
  .reading-note-trigger { color: inherit; background: transparent; }
  .knowledge-trigger { color: inherit; background: transparent; text-decoration: none; }
  .print-interactive-promo {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: .45in;
    min-height: 7.35in;
    padding: 1.15in .65in;
    color: #192321;
    background: #fff;
    break-after: page;
    border: 1px solid #aaa;
  }
  .print-interactive-promo div { max-width: 3.3in; }
  .print-interactive-promo strong { display: block; margin-bottom: .18in; font-family: var(--serif); font-size: 25pt; line-height: 1.12; }
  .print-interactive-promo p { margin: 0; font-size: 12pt; line-height: 1.55; }
  .print-interactive-promo span { display: grid; place-items: center; width: 1.55in; height: 1.55in; padding: .18in; color: #fff; background: #235d59; border: 7px solid #d5a447; border-radius: 50%; font-family: var(--sans); font-size: 12pt; font-weight: 800; line-height: 1.2; text-align: center; text-transform: uppercase; }
  .has-book-sidebar { padding-left: 0; }
  main.book-shell { padding: 0; }
  .book-shell { width: 100%; }
  .major-section { margin-top: .45in; }
  figure { break-inside: avoid; margin: .28in 0; }
  figure img { box-shadow: none; }
  .feature { break-inside: avoid; }
  h2, h3 { break-after: avoid; }
  .section-number { break-after: avoid; }
  a { color: inherit; text-decoration: none; }
  .compact-hero { min-height: auto; padding-top: .7in; }
  .publication-links { display: none; }
  .combined-front { min-height: 7.4in; break-after: page; padding: 1.5in 0 0; color: #000; background: #fff; }
  .combined-front .metadata-note { color: #333; }
  .combined-contents { break-after: page; }
  .combined-matter { break-before: page; border-top: 0; }
  .combined-chapter { break-before: page; }
  .combined-main { padding: 0; }
  .combined-back { break-before: page; border-top: 0; }
  .concept-index { grid-template-columns: 1fr 1fr; }
  .combined-edition { font-size: 9.1pt; line-height: 1.4; }
  .combined-edition .chapter-hero { min-height: auto; break-after: auto; padding: .48in 0 .36in; margin-bottom: .3in; border-bottom: 1px solid #aaa; }
  .combined-edition .chapter-hero h1 { margin: .08in 0 .12in; font-size: 30pt; }
  .combined-edition .chapter-promise { font-size: 12pt; }
  .combined-edition .major-section { margin-top: .28in; }
  .combined-edition h2 { font-size: 21pt; }
  .combined-edition h3 { font-size: 13pt; }
  .combined-edition figure { margin: .18in 0 .22in; }
  .combined-edition figure img { width: 80%; margin-inline: auto; }
  .combined-edition figcaption { width: 80%; margin: .08in auto 0; font-size: 7.8pt; line-height: 1.35; }
  .combined-edition .feature { margin: .2in 0; padding: .15in .18in; }
}


/* Shared presentation rules adapted from the approved Academy HTML edition. */
.academy-series-chapter { --ink:#192321; --muted:#596562; --paper:#f6f1e7; --panel:#fffdf8; --teal:#235d59; --teal-dark:#172e2c; --teal-soft:#dcebe7; --rust:#b44d32; --gold:#d5a447; --line:#d8d0c2; --serif:Georgia,"Times New Roman",serif; --sans:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif; color:var(--ink); background:var(--paper); }
:root {
      --ink: #192321;
      --muted: #596562;
      --paper: #f6f1e7;
      --panel: #fffdf8;
      --teal: #235d59;
      --teal-dark: #172e2c;
      --teal-soft: #dcebe7;
      --rust: #b44d32;
      --gold: #d5a447;
      --line: #d8d0c2;
      --serif: Georgia, "Times New Roman", serif;
      --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      --sidebar: 300px;
      --topbar: 50px;
      color-scheme: light;
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      overflow: hidden;
      color: var(--ink);
      background: var(--paper);
      font-family: var(--serif);
    }
    button, a { -webkit-tap-highlight-color: transparent; }
    button { font: inherit; }
    a { color: inherit; }
    :focus-visible { outline: 3px solid color-mix(in srgb, var(--gold) 85%, white); outline-offset: 3px; }
    .skip-link { position: fixed; z-index: 120; top: 10px; left: 10px; padding: 10px 14px; color: white; background: var(--teal-dark); transform: translateY(-150%); transition: transform .15s ease; font: 800 12px/1.2 var(--sans); }
    .skip-link:focus { transform: translateY(0); }

    .app {
      display: grid;
      grid-template-columns: var(--sidebar) minmax(0, 1fr);
      grid-template-rows: var(--topbar) minmax(0, 1fr);
      min-height: 100vh;
      height: 100dvh;
    }

    .bookbar {
      grid-column: 2;
      grid-row: 1;
      z-index: 20;
      display: flex;
      align-items: center;
      gap: 12px;
      min-width: 0;
      padding: 0 22px;
      border-bottom: 1px solid #d9d9d4;
      background: rgba(255, 253, 248, .98);
      box-shadow: 0 1px 7px rgba(25, 35, 33, .07);
      font-family: var(--sans);
    }
    .bookbar-mark { width: 23px; height: 23px; color: var(--teal); flex: none; }
    .bookbar-title { margin: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font: 700 15px/1.1 var(--serif); }
    .bookbar-author { margin: 0; color: var(--muted); font-size: 11px; white-space: nowrap; }
    .bookbar-spacer { flex: 1; }
    .chapter-pill {
      flex: none;
      padding: 5px 10px;
      border: 1px solid var(--line);
      border-radius: 999px;
      color: var(--teal);
      background: white;
      font-size: 9px;
      font-weight: 800;
      letter-spacing: .12em;
      text-transform: uppercase;
    }
    .progress-label { color: var(--muted); font-size: 10px; white-space: nowrap; }

    .sidebar {
      grid-column: 1;
      grid-row: 1 / -1;
      position: relative;
      z-index: 40;
      overflow-y: auto;
      color: #f7f2e8;
      background:
        radial-gradient(circle at 18% 0%, rgba(61, 126, 118, .16), transparent 34%),
        var(--teal-dark);
      border-right: 1px solid rgba(255, 255, 255, .09);
      scrollbar-color: rgba(255,255,255,.25) transparent;
    }
    .sidebar-inner { display: flex; min-height: 100%; flex-direction: column; }
    .toc-header {
      display: flex;
      align-items: flex-start;
      justify-content: space-between;
      gap: 12px;
      padding: 20px;
      border-bottom: 1px solid rgba(255,255,255,.15);
    }
    .toc-header h2 { margin: 0; color: #fffaf2; font: 400 18px/1.15 var(--serif); }
    .toc-edition { margin: 5px 0 0; color: var(--gold); font: 800 10px/1.2 var(--sans); letter-spacing: .14em; text-transform: uppercase; }
    .toc-nav { flex: 1; padding: 0 12px 24px; }
    .toc-label { margin: 0; padding: 20px 8px 8px; color: rgba(255,255,255,.5); font: 800 10px/1.2 var(--sans); letter-spacing: .14em; text-transform: uppercase; }
    .toc-chapter { margin: 0 0 12px; }
    .toc-chapter-title {
      display: grid;
      grid-template-columns: 30px minmax(0, 1fr);
      gap: 8px;
      margin: 0;
      padding: 10px 8px;
      color: rgba(255,255,255,.85);
      font: 600 13px/1.4 var(--sans);
    }
    .toc-chapter-title .chapter-no { color: var(--gold); font-size: 11px; font-weight: 800; font-variant-numeric: tabular-nums; }
    .toc-chapter-title a { color: inherit; text-decoration: none; }
    .toc-chapter-title a:hover { color: white; text-decoration: underline; text-decoration-color: rgba(213,164,71,.7); text-underline-offset: 3px; }
    .section-nav { margin: 0; padding: 0; list-style: none; }
    .section-nav li { margin: 0 0 2px; }
    .section-nav a {
      display: grid;
      grid-template-columns: 38px minmax(0, 1fr);
      gap: 10px;
      width: 100%;
      padding: 10px 8px;
      border-radius: 4px;
      color: rgba(255,255,255,.65);
      text-decoration: none;
      font: 500 12px/1.45 var(--sans);
      transition: color .16s ease, background .16s ease, box-shadow .16s ease;
    }
    .section-nav a:hover { color: white; background: rgba(255,255,255,.1); }
    .section-nav li.current a { color: white; background: rgba(213,164,71,.2); box-shadow: inset 3px 0 var(--gold); }
    .section-nav .sec-no { color: var(--gold); font-weight: 700; font-variant-numeric: tabular-nums; }

    .reader {
      grid-column: 2;
      grid-row: 2;
      min-width: 0;
      overflow-y: auto;
      scroll-padding-top: 22px;
      background: var(--paper);
    }
    .mobile-readerbar { display: none; }
    .section-status {
      border-bottom: 1px solid var(--line);
      background: var(--panel);
      font-family: var(--sans);
    }
    .section-status-inner {
      display: flex;
      justify-content: space-between;
      gap: 20px;
      max-width: 820px;
      margin: auto;
      padding: 9px 20px;
      color: var(--muted);
      font-size: 10px;
    }
    .section-status strong { color: var(--rust); letter-spacing: .1em; text-transform: uppercase; }

    .chapter-hero {
      color: #fffaf2;
      background:
        radial-gradient(circle at 89% 20%, rgba(64,126,119,.25), transparent 35%),
        linear-gradient(135deg, #153f3c, #235d59);
    }
    .book-shell { width: min(100% - 40px, 780px); margin-inline: auto; }
    .hero-inner { padding-block: 42px 46px; }
    .hero-label { margin: 0 0 18px; color: #e5b34a; font: 800 11px/1.2 var(--sans); letter-spacing: .2em; text-transform: uppercase; }
    .chapter-hero h1 { margin: 0; max-width: 740px; font: 400 clamp(37px, 4.15vw, 64px)/.99 var(--serif); letter-spacing: -.025em; }
    .chapter-promise { max-width: 640px; margin: 22px 0 0; color: #d8e6e2; font: 400 18px/1.5 var(--serif); }
    .hero-meta { display: flex; gap: 17px; margin-top: 24px; color: #adc7c1; font: 700 9px/1.2 var(--sans); letter-spacing: .12em; text-transform: uppercase; }

    .chapter-body { padding: 54px 0 95px; }
    .chapter-body p, .chapter-body li { font-size: 18px; line-height: 1.77; }
    .chapter-body p { margin: 0 0 1.3em; }
    .opening::first-letter { float: left; margin: .06em .13em 0 0; color: var(--rust); font-size: 4.4em; line-height: .74; }
    .lead { color: #34423f; font-size: 21px !important; line-height: 1.63 !important; }
    .chapter-roadmap {
      margin: 36px 0 54px;
      padding: 25px 28px 24px;
      border: 1px solid var(--line);
      border-top: 4px solid var(--gold);
      background: var(--panel);
      box-shadow: 0 10px 34px rgba(25,35,33,.05);
    }
    .eyebrow { margin: 0 0 10px !important; color: var(--rust); font: 800 10px/1.2 var(--sans) !important; letter-spacing: .17em; text-transform: uppercase; }
    .chapter-roadmap h2 { margin: 0 0 13px; font: 400 28px/1.2 var(--serif); }
    .chapter-roadmap ol { display: grid; grid-template-columns: 1fr 1fr; gap: 7px 34px; margin: 0; padding-left: 20px; }
    .chapter-roadmap li { color: var(--muted); font: 600 12px/1.5 var(--sans); }
    .major-section { scroll-margin-top: 52px; padding: 52px 0 12px; border-top: 1px solid var(--line); }
    .section-heading { display: grid; grid-template-columns: 58px minmax(0, 1fr); gap: 20px; align-items: start; margin-bottom: 27px; }
    .section-number { padding-top: 4px; color: var(--rust); font: 400 22px/1 var(--serif); }
    .section-heading h2 { margin: 0; font: 400 clamp(31px, 3vw, 44px)/1.1 var(--serif); letter-spacing: -.025em; }
    .section-heading p { grid-column: 2; margin: -10px 0 0; color: var(--muted); font: 700 10px/1.4 var(--sans); letter-spacing: .13em; text-transform: uppercase; }
    .knowledge-trigger {
      border: 0;
      border-bottom: 1px dotted var(--teal);
      padding: 0;
      color: var(--teal);
      background: none;
      cursor: pointer;
      font: inherit;
    }
    .knowledge-trigger:hover { color: var(--rust); border-color: var(--rust); }
    .note-trigger {
      display: inline-grid;
      place-items: center;
      width: 17px;
      height: 17px;
      margin-left: 2px;
      border: 0;
      border-radius: 50%;
      color: white;
      background: var(--teal);
      cursor: pointer;
      font: 800 9px/1 var(--sans);
      vertical-align: super;
    }
    .note-trigger:hover { background: var(--rust); }
    .feature-panel {
      position: relative;
      margin: 31px 0 34px;
      padding: 26px 28px 23px;
      border: 1px solid var(--line);
      border-top: 4px solid var(--teal);
      background: var(--panel);
    }
    .feature-panel.gold { border-top-color: var(--gold); }
    .feature-panel.rust { border-top-color: var(--rust); }
    .feature-title { margin: 0 0 9px; color: var(--teal); font: 800 10px/1.3 var(--sans); letter-spacing: .16em; text-transform: uppercase; }
    .feature-panel h3 { margin: 0 0 9px; font: 400 25px/1.2 var(--serif); }
    .feature-panel p:last-child { margin-bottom: 0; }
    .plain-list { margin: 0 0 28px; padding-left: 24px; }
    .plain-list li { margin-bottom: 10px; padding-left: 7px; }
    .plain-list li::marker { color: var(--rust); }
    .skill-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 13px; margin: 28px 0 35px; }
    .skill-card { min-height: 172px; padding: 20px 18px; border: 1px solid var(--line); background: var(--panel); }
    .skill-icon { display: grid; place-items: center; width: 38px; height: 38px; margin-bottom: 15px; border: 1px solid #8eb8b1; border-radius: 50%; color: var(--teal); background: #eef6f3; font: 700 16px var(--sans); }
    .skill-card h3 { margin: 0 0 7px; font: 400 20px/1.2 var(--serif); }
    .skill-card p { margin: 0; color: var(--muted); font: 500 12px/1.55 var(--sans); }

    .figure {
      margin: 35px 0 42px;
      padding: 28px 24px 20px;
      border: 1px solid var(--line);
      background: var(--panel);
    }
    .figure-title { margin: 0 0 5px; text-align: center; font: 400 24px/1.25 var(--serif); }
    .figure-subtitle { margin: 0 0 24px !important; color: var(--muted); text-align: center; font: 700 9px/1.5 var(--sans) !important; letter-spacing: .13em; text-transform: uppercase; }
    .process-diagram { display: block; width: 100%; height: auto; overflow: visible; }
    .process-diagram text:not([fill]) { font-family: var(--sans); fill: var(--ink); }
    .figure figcaption { margin-top: 17px; padding-top: 15px; border-top: 1px solid var(--line); color: var(--muted); font: 500 11px/1.55 var(--sans); }
    .figure figcaption strong { color: var(--rust); text-transform: uppercase; letter-spacing: .08em; }
    .audio-description { margin-top: 9px; color: var(--muted); font-family: var(--sans); font-size: .79rem; }
    .audio-description summary { width: fit-content; cursor: pointer; color: var(--teal); font-weight: 750; }
    .audio-description summary:hover { color: var(--rust); }
    .chapter-body .audio-description p { margin: 8px 0 0; font: 500 .79rem/1.6 var(--sans); }
    .mobile-flow { display: none; }

    .comparison { width: 100%; margin: 28px 0 35px; border-collapse: collapse; background: var(--panel); font-family: var(--sans); }
    .comparison th { padding: 12px 15px; color: white; background: var(--teal-dark); text-align: left; font-size: 10px; letter-spacing: .1em; text-transform: uppercase; }
    .comparison td { padding: 15px; border: 1px solid var(--line); color: var(--muted); font-size: 12px; line-height: 1.5; vertical-align: top; }
    .comparison td:first-child { width: 22%; color: var(--ink); font-weight: 800; }
    .comparison .good { color: var(--teal); }
    .comparison .careful { color: var(--rust); }

    .practice {
      margin: 32px 0 20px;
      padding: 31px;
      color: #f8f2e8;
      background: var(--teal-dark);
      box-shadow: 0 14px 35px rgba(23,46,44,.16);
    }
    .practice .eyebrow { color: var(--gold); }
    .practice h3 { margin: 0 0 12px; color: white; font: 400 29px/1.2 var(--serif); }
    .practice p { color: #ccd9d6; }
    .practice ol { margin: 22px 0 0; padding: 0; list-style: none; counter-reset: steps; }
    .practice li { position: relative; margin: 0 0 18px; padding-left: 43px; color: #e9efed; font: 500 13px/1.55 var(--sans); counter-increment: steps; }
    .practice li::before { content: counter(steps); position: absolute; left: 0; top: -2px; display: grid; place-items: center; width: 28px; height: 28px; border: 1px solid var(--gold); border-radius: 50%; color: var(--gold); font-weight: 800; }
    .prompt-box { margin-top: 23px; padding: 18px 20px; border-left: 4px solid var(--gold); color: var(--ink); background: #eef4f1; font: 500 14px/1.65 var(--sans); }
    .prompt-box strong { display: block; margin-bottom: 6px; color: var(--rust); font-size: 9px; letter-spacing: .14em; text-transform: uppercase; }
    .grounding-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; align-items: start; margin: 28px 0; }
    .grounding-card { height: 100%; margin: 0; }
    .grounding-card .plain-list, .review-checklist .plain-list { margin-bottom: 0; }
    .grounding-source-link { margin: 18px 0 0 !important; padding-top: 16px; border-top: 1px solid var(--line); font: 600 12px/1.6 var(--sans) !important; }
    .image-prompt { margin: 30px 0; }
    .prompt-copy { margin: 8px 0 0; overflow: auto; white-space: pre-wrap; overflow-wrap: anywhere; color: var(--ink); font: 500 12px/1.65 var(--sans); }
    .generated-example img { display: block; width: min(100%, 620px); height: auto; margin: 0 auto; border: 1px solid var(--line); background: var(--teal-dark); box-shadow: 0 18px 45px rgba(23,46,44,.16); }

    .remember { margin: 48px 0 30px; padding: 30px; border: 1px solid #a9c9c3; background: var(--teal-soft); }
    .remember h2 { margin: 0 0 16px; color: var(--teal); font: 400 30px/1.2 var(--serif); }
    .remember ul { margin: 0; padding-left: 22px; }
    .remember li { margin-bottom: 7px; font-size: 16px; }
    .reflection, .endnotes { padding: 42px 0 15px; border-top: 1px solid var(--line); }
    .reflection h2, .endnotes h2 { margin: 0 0 16px; font: 400 33px/1.2 var(--serif); }
    .reflection ol { padding-left: 23px; }
    .endnotes ol { margin: 0; padding-left: 25px; }
    .endnotes li { margin-bottom: 16px; color: var(--muted); font: 500 12px/1.6 var(--sans); }
    .endnotes a { color: var(--teal); text-underline-offset: 3px; }
    .chapter-close { margin-top: 48px; padding: 33px 0 0; border-top: 4px solid var(--gold); text-align: center; }
    .chapter-close p { margin: 8px 0; color: var(--muted); font: 700 10px/1.5 var(--sans); letter-spacing: .14em; text-transform: uppercase; }
    .chapter-close strong { display: block; font: 400 29px/1.3 var(--serif); }

    .drawer-backdrop {
      position: fixed;
      inset: 0;
      z-index: 80;
      border: 0;
      padding: 0;
      background: rgba(15, 29, 28, .56);
      opacity: 0;
      pointer-events: none;
      transition: opacity .2s ease;
    }
    .drawer-backdrop.open { opacity: 1; pointer-events: auto; }
    .drawer {
      position: fixed;
      z-index: 90;
      inset: 0 0 0 auto;
      width: min(600px, calc(100vw - 64px));
      overflow-y: auto;
      border-left: 5px solid var(--gold);
      color: var(--ink);
      background: var(--panel);
      box-shadow: -18px 0 55px rgba(12,26,25,.25);
      transform: translateX(105%);
      transition: transform .24s ease;
    }
    .drawer.open { transform: translateX(0); }
    .drawer-inner { padding: 42px 47px 64px; }
    .drawer-close {
      position: absolute;
      top: 20px;
      right: 22px;
      display: grid;
      place-items: center;
      width: 38px;
      height: 38px;
      border: 1px solid transparent;
      color: var(--ink);
      background: transparent;
      cursor: pointer;
      font: 300 29px/1 var(--sans);
    }
    .drawer-close:hover { border-color: var(--line); background: var(--paper); }
    .drawer-kicker { margin: 0 0 17px; color: var(--rust); font: 800 10px/1.2 var(--sans); letter-spacing: .16em; text-transform: uppercase; }
    .drawer h2 { margin: 0 45px 28px 0; font: 400 39px/1.08 var(--serif); }
    .drawer-lede { margin: 0 0 28px; padding: 27px 0; border-block: 1px solid var(--line); font-size: 22px; line-height: 1.52; }
    .drawer-section { padding: 24px 0; border-bottom: 1px solid var(--line); }
    .drawer-section h3 { margin: 0 0 9px; font: 400 21px/1.25 var(--serif); }
    .drawer-section p { margin: 0; color: var(--muted); font-size: 16px; line-height: 1.68; }
    .drawer-callout { margin-top: 27px; padding: 19px 21px; border: 1px solid #a9c9c3; background: var(--teal-soft); }
    .drawer-callout strong { display: block; margin-bottom: 6px; color: var(--teal); font: 800 10px/1.2 var(--sans); letter-spacing: .12em; text-transform: uppercase; }
    .drawer-callout p { margin: 0; font-size: 15px; line-height: 1.55; }
    .drawer-source { display: inline-block; margin-top: 24px; color: var(--teal); font: 700 12px/1.4 var(--sans); text-underline-offset: 3px; }
    .drawer-source[hidden], .drawer-callout[hidden] { display: none; }

    .menu-button, .mobile-close { display: none; }

    @media (max-width: 1040px) {
      .app { grid-template-columns: 1fr; grid-template-rows: var(--topbar) auto minmax(0,1fr); }
      .bookbar { grid-column: 1; grid-row: 1; padding: 0 16px; }
      .sidebar { position: fixed; inset: 0 auto 0 0; width: min(86vw, 330px); transform: translateX(-105%); transition: transform .22s ease; }
      .sidebar.open { transform: translateX(0); }
      .mobile-close { position: static; display: grid; place-items: center; width: 34px; height: 34px; border: 0; border-radius: 4px; color: rgba(255,255,255,.75); background: transparent; cursor: pointer; font-size: 22px; }
      .mobile-close:hover { color: white; background: rgba(255,255,255,.1); }
      .bookbar-mark { display: none; }
      .menu-button { display: inline-flex; align-items: center; gap: 8px; border: 0; padding: 8px 6px 8px 0; color: var(--teal); background: transparent; cursor: pointer; font: 800 10px/1 var(--sans); letter-spacing: .08em; text-transform: uppercase; }
      .menu-button svg { width: 19px; height: 19px; }
      .progress-label { display: none; }
      .reader { grid-column: 1; grid-row: 2 / -1; }
      .mobile-readerbar { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 13px 18px; color: #fffaf2; background: var(--teal-dark); font: 700 10px/1.2 var(--sans); letter-spacing: .1em; text-transform: uppercase; }
      .mobile-readerbar span:last-child { color: var(--gold); }
      .drawer { width: min(650px, calc(100vw - 36px)); }
    }

    @media (max-width: 700px) {
      :root { --topbar: 48px; }
      .bookbar { gap: 9px; }
      .bookbar-title { font-size: 14px; }
      .bookbar-author, .chapter-pill { display: none; }
      .book-shell { width: min(100% - 34px, 780px); }
      .hero-inner { padding-block: 34px 37px; }
      .chapter-hero h1 { font-size: clamp(34px, 11vw, 48px); line-height: 1.01; }
      .chapter-promise { margin-top: 17px; font-size: 17px; }
      .hero-meta { flex-wrap: wrap; row-gap: 8px; }
      .section-status-inner { padding-inline: 17px; }
      .section-status-inner span:first-child { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
      .chapter-body { padding: 39px 0 74px; }
      .chapter-body p, .chapter-body li { font-size: 17px; line-height: 1.74; }
      .lead { font-size: 19px !important; }
      .chapter-roadmap { margin: 29px 0 38px; padding: 22px 21px; }
      .chapter-roadmap ol { grid-template-columns: 1fr; }
      .grounding-grid { grid-template-columns: 1fr; }
      .prompt-copy { font-size: 11px; }
      .major-section { padding-top: 42px; }
      .section-heading { grid-template-columns: 46px 1fr; gap: 8px; }
      .section-heading h2 { font-size: 31px; }
      .section-heading p { grid-column: 1 / -1; margin-top: 1px; }
      .skill-grid { grid-template-columns: 1fr; }
      .skill-card { min-height: 0; }
      .figure { margin-inline: -6px; padding: 24px 17px 18px; }
      .process-diagram { display: none; }
      .mobile-flow { display: grid; gap: 10px; margin-top: 21px; }
      .mobile-step { display: grid; grid-template-columns: 38px 1fr; gap: 12px; align-items: center; padding: 12px; border: 1px solid var(--line); background: white; }
      .mobile-step b { display: grid; place-items: center; width: 34px; height: 34px; border: 1px solid var(--teal); border-radius: 50%; color: var(--teal); font: 800 12px var(--sans); }
      .mobile-step strong { display: block; font: 700 13px/1.3 var(--sans); }
      .mobile-step span { color: var(--muted); font: 500 11px/1.4 var(--sans); }
      .comparison-wrap { overflow-x: auto; margin-inline: -17px; padding-inline: 17px; }
      .comparison { min-width: 620px; }
      .practice { margin-inline: -6px; padding: 26px 22px; }
      .drawer { inset: auto 0 0; width: 100%; max-height: 92dvh; border-top: 5px solid var(--gold); border-left: 0; transform: translateY(105%); }
      .drawer.open { transform: translateY(0); }
      .drawer-inner { padding: 35px 25px 52px; }
      .drawer h2 { font-size: 33px; }
      .drawer-lede { font-size: 20px; }
    }

    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .001ms !important; }
    }

    @media print {
      @page { size: 6in 9in; margin: .7in .65in .75in; }
      body { overflow: visible; background: white; }
      .app { display: block; height: auto; }
      .sidebar, .bookbar, .mobile-readerbar, .section-status, .drawer, .drawer-backdrop, .audio-description { display: none !important; }
      .reader { overflow: visible; }
      .book-shell { width: 100%; }
      .chapter-hero { margin: -.7in -.65in 0; padding: .7in .65in .45in; print-color-adjust: exact; -webkit-print-color-adjust: exact; }
      .chapter-hero h1 { font-size: 34pt; }
      .chapter-body { padding-top: .45in; }
      .major-section { break-before: page; }
      .figure, .feature-panel, .practice, .remember { break-inside: avoid; }
      .knowledge-trigger { color: inherit; border: 0; }
      .note-trigger { color: var(--teal); background: none; vertical-align: super; }
      .endnotes a::after { content: " (" attr(href) ")"; font-size: 8pt; }
    }


:root {
  --ink: #192321;
  --ink-deep: #172e2c;
  --paper: #f6f1e7;
  --panel: #fffdf8;
  --teal: #235d59;
  --teal-soft: #dcebe7;
  --gold: #d5a447;
  --rust: #b44d32;
  --line: #d8d0c2;
  --muted: #596562;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html { overflow-x: hidden; overflow-y: auto; }
body { margin: 0; overflow-x: hidden; overflow-y: auto; color: var(--ink); background: var(--paper); font: 16px/1.6 var(--sans); -webkit-font-smoothing: antialiased; }
body.dialog-open { overflow: hidden; }
a { color: inherit; }
button, input { font: inherit; }
img, svg { max-width: 100%; }
:focus-visible { outline: 3px solid var(--gold); outline-offset: 4px; }
.skip-link { position: fixed; z-index: 100; top: .75rem; left: .75rem; transform: translateY(-180%); padding: .7rem 1rem; color: var(--panel); background: var(--ink-deep); font-weight: 800; }
.skip-link:focus { transform: translateY(0); }
.public-header { position: sticky; z-index: 50; top: 0; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; min-height: 5rem; padding: 0 clamp(1rem, 4vw, 4rem); border-bottom: 1px solid var(--line); background: rgba(255,253,248,.96); backdrop-filter: blur(14px); }
.public-brand { display: inline-flex; align-items: center; gap: .65rem; font-weight: 900; letter-spacing: -.035em; text-decoration: none; text-transform: uppercase; }
.public-brand img, .public-footer a:first-child img { flex: 0 0 auto; border-radius: .5rem; }
.public-header nav { display: flex; gap: clamp(1rem, 3vw, 2.75rem); }
.public-header nav a, .public-sign-in { text-decoration: none; }
.public-header nav a:hover, .public-sign-in:hover { color: var(--teal); }
.public-sign-in { justify-self: end; color: var(--teal); font-weight: 800; }
.public-footer { display: flex; max-width: 1240px; align-items: center; justify-content: space-between; gap: 1rem; margin: 0 auto; padding: 3rem clamp(1rem, 4vw, 4rem); border-top: 1px solid var(--line); }
.public-footer a:first-child { display: inline-flex; align-items: center; gap: .65rem; font-weight: 900; text-transform: uppercase; }
.public-footer a:last-child { color: var(--teal); font-weight: 800; }
.section-label { margin: 0 0 .8rem; color: var(--rust); font-size: .78rem; font-weight: 900; letter-spacing: .13em; text-transform: uppercase; }
.button { display: inline-flex; min-height: 3.6rem; align-items: center; justify-content: center; padding: .8rem 1.4rem; border: 1px solid var(--ink); cursor: pointer; font-weight: 850; text-align: center; text-decoration: none; }
.button-primary { border-color: var(--teal); color: var(--panel); background: var(--teal); }
.button-secondary { background: var(--panel); }
.text-link { color: var(--teal); font-weight: 850; text-decoration: none; }
.catalog-hero { padding: clamp(5rem, 10vw, 9rem) clamp(1.25rem, 8vw, 8rem); color: var(--panel); background: var(--ink-deep); }
.catalog-hero h1 { max-width: 10ch; margin: 0; font: 500 clamp(3.6rem, 8vw, 7.5rem)/.94 var(--serif); letter-spacing: -.055em; }
.catalog-hero > p:last-child { max-width: 48rem; margin: 2rem 0 0; font-size: clamp(1.1rem, 2vw, 1.35rem); color: #dce5e2; }
.catalog-list { max-width: 1240px; margin: 0 auto; padding: clamp(3rem, 7vw, 7rem) clamp(1rem, 4vw, 4rem); }
.catalog-book { display: grid; grid-template-columns: minmax(150px, 230px) 1fr; gap: clamp(1.5rem, 5vw, 5rem); align-items: center; padding: 2.5rem 0; border-top: 1px solid var(--line); }
.catalog-book:last-child { border-bottom: 1px solid var(--line); }
.catalog-cover { display: block; aspect-ratio: 4 / 5; overflow: hidden; background: var(--teal-soft); }
.catalog-cover img { width: 100%; height: 100%; object-fit: cover; }
.generated-cover { display: flex; width: 100%; height: 100%; min-height: 260px; flex-direction: column; justify-content: space-between; padding: 1.4rem; color: var(--panel); background: var(--ink-deep); }
.generated-cover > span { color: var(--gold); font-size: .72rem; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
.generated-cover > strong { font: 500 clamp(1.8rem, 4vw, 3rem)/1 var(--serif); letter-spacing: -.04em; }
.generated-cover > small { color: #c9d6d3; }
.catalog-book h2 { max-width: 16ch; margin: 0 0 .8rem; font: 500 clamp(2rem, 4vw, 3.5rem)/1 var(--serif); letter-spacing: -.04em; }
.catalog-book h2 a { text-decoration: none; }
.catalog-book > div > p:not(.section-label) { max-width: 48rem; color: var(--muted); }
.book-detail { display: grid; grid-template-columns: minmax(280px, .75fr) 1.25fr; min-height: 72vh; background: var(--panel); }
.book-detail-cover { display: grid; place-items: center; padding: clamp(2rem, 6vw, 6rem); background: var(--teal-soft); }
.book-detail-cover img { width: min(100%, 390px); box-shadow: 0 28px 70px rgba(23,46,44,.2); }
.book-detail-cover > .generated-cover { width: min(100%, 390px); min-height: 500px; box-shadow: 0 28px 70px rgba(23,46,44,.2); }
.book-detail-copy { display: flex; flex-direction: column; justify-content: center; padding: clamp(3rem, 8vw, 8rem); }
.book-detail-copy h1 { max-width: 13ch; margin: 0; font: 500 clamp(3rem, 6vw, 6rem)/.96 var(--serif); letter-spacing: -.055em; }
.book-subtitle { max-width: 42rem; font-size: clamp(1.2rem, 2vw, 1.55rem); }
.book-detail-copy > p:not(.section-label) { max-width: 46rem; color: var(--muted); }
.book-detail-copy dl { display: flex; flex-wrap: wrap; gap: 1.5rem 3rem; margin: 1.5rem 0 2rem; }
.book-detail-copy dl div { min-width: 8rem; }
.book-detail-copy dt { color: var(--muted); font-size: .78rem; font-weight: 800; text-transform: uppercase; }
.book-detail-copy dd { margin: .15rem 0 0; font-weight: 750; }
.book-detail-copy .button { align-self: flex-start; }
.book-contents { max-width: 1120px; margin: 0 auto; padding: clamp(4rem, 8vw, 8rem) clamp(1rem, 4vw, 4rem); }
.section-heading { display: grid; grid-template-columns: .7fr 1.3fr; gap: 2rem; margin-bottom: 3rem; }
.section-heading .section-label { grid-column: 1 / -1; }
.section-heading h2 { max-width: 12ch; margin: 0; font: 500 clamp(2.5rem, 5vw, 5rem)/.96 var(--serif); letter-spacing: -.05em; }
.section-heading > p:last-child { max-width: 36rem; margin: 0; color: var(--muted); font-size: 1.1rem; }
.book-contents ol { padding: 0; list-style: none; }
.chapter-row { display: grid; grid-template-columns: 3rem 1fr auto; gap: 1rem; align-items: start; padding: 1.35rem 0; border-top: 1px solid var(--line); }
.chapter-row:last-child { border-bottom: 1px solid var(--line); }
.chapter-row > span { color: var(--rust); font-weight: 900; }
.chapter-row strong { display: block; font-size: 1.08rem; }
.chapter-row small { display: block; max-width: 54rem; margin-top: .3rem; color: var(--muted); }
.chapter-row > a { color: var(--teal); font-weight: 800; text-decoration: none; white-space: nowrap; }
.chapter-row.is-locked { opacity: .72; }
.chapter-breadcrumb { display: flex; flex-wrap: wrap; gap: .45rem; max-width: 1120px; margin: 0 auto; padding: 1.25rem clamp(1rem, 4vw, 3rem); color: var(--muted); font-size: .9rem; }
.chapter-breadcrumb a { color: var(--teal); }
.public-chapter-heading { padding: clamp(4rem, 9vw, 8rem) clamp(1rem, 8vw, 8rem); color: var(--panel); background: var(--ink-deep); }
.public-chapter-heading h1 { max-width: 15ch; margin: 0; font: 500 clamp(3.2rem, 7vw, 7rem)/.96 var(--serif); letter-spacing: -.055em; }
.public-chapter-heading > p:last-child { max-width: 52rem; margin: 2rem 0 0; color: #dce5e2; font-size: clamp(1.08rem, 2vw, 1.35rem); }
.public-chapter-content { overflow: clip; background: var(--panel); }
.public-chapter-content > .academy-series-chapter, .public-chapter-content > .chapter-hero, .public-chapter-content > .book-shell { max-width: none; }
.academy-promotion { margin: clamp(3rem, 8vw, 7rem) auto; max-width: 1080px; padding: clamp(2rem, 6vw, 5rem); color: var(--panel); background: var(--ink-deep); }
.academy-promotion h2 { max-width: 15ch; margin: 0; font: 500 clamp(2.5rem, 5vw, 5rem)/.98 var(--serif); letter-spacing: -.045em; }
.academy-promotion > p:not(.section-label) { max-width: 50rem; color: #dce5e2; font-size: 1.12rem; }
.promotion-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 2rem; }
.academy-promotion .button-secondary { color: var(--ink); }
.kids-public-screen { display: grid; grid-template-columns: 1fr 1fr; min-height: 70vh; border-bottom: 1px solid var(--line); background: var(--panel); }
.kids-screen-copy { display: flex; flex-direction: column; justify-content: center; padding: clamp(2rem, 7vw, 7rem); border-left: .5rem solid var(--kids-accent); }
.kids-screen-copy h2 { margin: 0; font: 500 clamp(2.5rem, 5vw, 5rem)/.98 var(--serif); letter-spacing: -.045em; }
.kids-big-idea { font-size: 1.35rem; font-weight: 800; }
.kids-public-screen img { width: 100%; height: 100%; object-fit: cover; }
dialog { width: min(calc(100% - 2rem), 680px); max-height: calc(100vh - 2rem); padding: 0; border: 0; color: var(--ink); background: transparent; }
dialog::backdrop { background: rgba(10,27,25,.72); backdrop-filter: blur(5px); }
.registration-panel, .knowledge-dialog > div { position: relative; overflow: auto; max-height: calc(100vh - 2rem); padding: clamp(1.5rem, 5vw, 3.5rem); border: 1px solid var(--line); background: var(--panel); box-shadow: 0 30px 90px rgba(0,0,0,.28); }
.registration-panel h2, .knowledge-dialog h2 { margin: 0; font: 500 clamp(2.2rem, 5vw, 4rem)/.98 var(--serif); letter-spacing: -.045em; }
.dialog-close, [data-close-knowledge] { position: absolute; top: .8rem; right: .8rem; width: 2.7rem; height: 2.7rem; border: 1px solid var(--line); cursor: pointer; color: var(--ink); background: var(--panel); font-size: 1.6rem; }
.registration-fields { display: grid; gap: 1rem; margin: 1.5rem 0; }
.registration-fields label { font-size: .9rem; font-weight: 800; }
.registration-fields input { width: 100%; min-height: 3.4rem; margin-top: .35rem; padding: .7rem .85rem; border: 1px solid #8c9693; color: var(--ink); background: #fff; }
.registration-submit { width: 100%; }
.registration-message { min-height: 1.5rem; color: var(--rust); font-weight: 750; }
.registration-privacy { color: var(--muted); font-size: .84rem; }
.registration-privacy a { color: var(--teal); font-weight: 800; }
.honeypot { position: absolute !important; left: -10000px !important; width: 1px !important; height: 1px !important; overflow: hidden !important; }
.knowledge-dialog { width: min(calc(100% - 2rem), 780px); }
.knowledge-dialog [data-knowledge-content] { margin-top: 1.5rem; }

@media (max-width: 760px) {
  .public-header { grid-template-columns: 1fr auto; min-height: 4.25rem; }
  .public-header nav { display: none; }
  .public-sign-in { grid-column: 2; }
  .public-footer { align-items: flex-start; flex-direction: column; }
  .catalog-book, .book-detail, .kids-public-screen, .section-heading { grid-template-columns: 1fr; }
  .catalog-book { gap: 1.5rem; }
  .catalog-cover { width: min(70vw, 260px); }
  .book-detail-copy { padding: 3rem 1.25rem; }
  .book-detail-copy h1 { font-size: clamp(3rem, 14vw, 5rem); }
  .chapter-row { grid-template-columns: 2.4rem 1fr; }
  .chapter-row > a { grid-column: 2; white-space: normal; }
  .public-chapter-heading { padding: 4rem 1.25rem; }
  .public-chapter-heading h1 { font-size: clamp(3rem, 14vw, 5rem); }
  .academy-promotion { margin: 2rem 1rem; padding: 2rem 1.25rem; }
  .promotion-actions { align-items: stretch; flex-direction: column; }
  .kids-public-screen img { min-height: 320px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}