@import url("https://fonts.googleapis.com/css2?family=Cormorant+Garamond:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500&family=Manrope:wght@400;500;600;700&display=swap");

:root {
  color-scheme: light;
  --accent: #6f67d9;
  --accent-soft: color-mix(in srgb, var(--accent) 8%, #f4efe5);
  --ink: #171714;
  --muted: #69675f;
  --paper: #f3eee4;
  --paper-deep: #e8e0d2;
  --surface: rgba(255, 253, 247, 0.82);
  --line: rgba(23, 23, 20, 0.15);
  --rail-width: 17.25rem;
  --serif: "Cormorant Garamond", Georgia, "Times New Roman", "Noto Serif SC", serif;
  --sans: Manrope, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  font-family: var(--sans);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--paper); }
body {
  margin: 0;
  min-width: 0;
  overflow-x: hidden;
  color: var(--ink);
  background-color: var(--paper);
  background-image: url("paper.jpg");
  background-size: 80rem auto;
  font-size: clamp(1rem, 0.96rem + 0.12vw, 1.08rem);
  line-height: 1.68;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
img, svg, video { max-width: 100%; }
code { padding: 0.1em 0.35em; border-radius: 0.25rem; background: #e9ebf4; font-size: 0.9em; }
pre { overflow-x: auto; padding: 1.2rem; border-radius: 0.35rem; background: #172038; color: #f8f9ff; }
pre code { padding: 0; background: transparent; color: inherit; }

.reader-layout { display: grid; grid-template-columns: var(--rail-width) minmax(0, 1fr); min-height: 100vh; }
.reader-rail {
  position: sticky;
  z-index: 8;
  top: 0;
  display: flex;
  flex-direction: column;
  height: 100vh;
  min-width: 0;
  padding: 1.7rem 1.35rem 1.35rem;
  border-right: 1px solid var(--line);
  background-color: rgba(248, 244, 236, 0.86);
  background-image: url("paper.jpg");
  background-size: 70rem auto;
  backdrop-filter: blur(10px);
}
.reader-wordmark {
  width: fit-content;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}
.reader-book-identity { display: grid; gap: 0.35rem; margin: 2.65rem 0 1.55rem; }
.reader-book-identity > span, .section-kicker, .book-object-kicker {
  margin: 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}
.reader-brand { width: fit-content; font-family: var(--serif); font-size: 1.82rem; line-height: 0.98; }
.rail-menu-toggle { display: none; }
.rail-chapters { min-height: 0; overflow: auto; border-top: 1px solid var(--line); scrollbar-width: thin; }
.rail-chapter {
  position: relative;
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: 0.35rem;
  align-items: start;
  padding: 0.72rem 0.25rem;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}
.rail-chapter::before {
  position: absolute;
  top: 0.62rem;
  bottom: 0.62rem;
  left: -1.15rem;
  width: 3px;
  border-radius: 999px;
  background: transparent;
  content: "";
}
.rail-chapter > span { padding-top: 0.08rem; font-size: 0.68rem; font-variant-numeric: tabular-nums; }
.rail-chapter strong { overflow-wrap: anywhere; font-size: 0.76rem; font-weight: 620; line-height: 1.35; }
.rail-chapter:hover, .rail-chapter.is-current, .rail-chapter.is-selected { color: var(--ink); }
.rail-chapter.is-current, .rail-chapter.is-selected { background: var(--accent-soft); }
.rail-chapter.is-current::before, .rail-chapter.is-selected::before { background: var(--accent); }

.reader-stage { min-width: 0; animation: stage-in 520ms cubic-bezier(.2,.8,.2,1) both; }
.book-index-stage { padding: clamp(2.5rem, 6vw, 6rem) clamp(1.5rem, 6vw, 6.5rem) 6rem; }
.book-hero {
  display: grid;
  grid-template-columns: minmax(15rem, 22rem) minmax(16rem, 1fr);
  gap: clamp(3rem, 8vw, 9rem);
  align-items: center;
  min-height: 72vh;
  max-width: 76rem;
  margin: 0 auto;
}
.book-object {
  position: relative;
  display: flex;
  flex-direction: column;
  aspect-ratio: 0.72;
  min-width: 0;
  padding: clamp(1.8rem, 4vw, 3rem);
  border: 1px solid rgba(0, 0, 0, 0.22);
  border-radius: 0.18rem 0.65rem 0.65rem 0.18rem;
  color: white;
  background-color: var(--accent);
  background-image: var(--cover-image);
  background-size: cover;
  box-shadow: 1.2rem 1.65rem 2.8rem rgba(47, 38, 25, 0.22), inset 0.2rem 0 0 rgba(255,255,255,.12);
  transform: perspective(70rem) rotateY(-5deg);
  transform-origin: left center;
  transition: transform 320ms ease, box-shadow 320ms ease;
}
.book-object::before {
  position: absolute;
  inset: 0 auto 0 1.2rem;
  width: 1px;
  background: rgba(255, 255, 255, 0.24);
  content: "";
}
.book-object::after {
  position: absolute;
  z-index: -1;
  top: 0.5rem;
  right: -0.75rem;
  bottom: -0.5rem;
  width: 0.8rem;
  border-radius: 0 0.45rem 0.45rem 0;
  background: #eee8dc;
  box-shadow: 0.25rem 0.3rem 0.8rem rgba(25, 35, 60, 0.16);
  content: "";
}
.book-object:hover { transform: perspective(70rem) rotateY(-1deg) translateY(-0.35rem); box-shadow: 1.8rem 2.6rem 5rem rgba(31, 42, 72, 0.24); }
.tactile-cover[data-book-id="memova"],
.tactile-book[data-book-id="memova"] { --cover-image: url("covers/memova-cloth.jpg"); }
.tactile-cover[data-book-id="invest"],
.tactile-book[data-book-id="invest"] { --cover-image: url("covers/invest-cloth.jpg"); }
.tactile-cover[data-book-id="card-game-lab"],
.tactile-book[data-book-id="card-game-lab"] { --cover-image: url("covers/card-game-lab-cloth.jpg"); }
.tactile-cover[data-book-id="pressure-vessel-solver"],
.tactile-book[data-book-id="pressure-vessel-solver"] { --cover-image: url("covers/pressure-vessel-solver-cloth.jpg"); }
.tactile-cover[data-book-id="who-owns-the-future-you"],
.tactile-book[data-book-id="who-owns-the-future-you"] { --cover-image: url("covers/who-owns-the-future-you-cloth.jpg"); }
.tactile-cover[data-book-id="about-me"],
.tactile-book[data-book-id="about-me"] { --cover-image: url("covers/about-me-cloth.jpg"); }
.tactile-cover[data-book-id="family-book"],
.tactile-book[data-book-id="family-book"] { --cover-image: url("covers/family-book-cloth.jpg"); }
.book-object-kicker { color: rgba(255, 255, 255, 0.7); }
.book-object h1 { max-width: 10ch; margin: auto 0 1rem; font-family: var(--serif); font-size: clamp(3rem, 5.5vw, 5.2rem); font-weight: 400; letter-spacing: -0.035em; line-height: 0.9; }
.book-object p { max-width: 28rem; margin: 0; overflow-wrap: anywhere; color: rgba(255, 255, 255, 0.78); font-size: 0.94rem; line-height: 1.5; }
.book-object-count { margin-top: 1.6rem; color: rgba(255, 255, 255, 0.64); font-size: 0.68rem; letter-spacing: 0.14em; text-transform: uppercase; }
.book-opening { max-width: 34rem; }
.book-opening h2, .chapter-route > h2, .library-intro h1 {
  margin: 0.85rem 0 1.1rem;
  font-family: var(--serif);
  font-size: clamp(3rem, 7vw, 6.8rem);
  font-weight: 400;
  letter-spacing: -0.04em;
  line-height: 0.9;
}
.book-opening > p:not(.section-kicker) { color: var(--muted); font-size: clamp(1.05rem, 1rem + 0.45vw, 1.35rem); }
.primary-link {
  display: inline-flex;
  gap: 1.4rem;
  align-items: center;
  margin-top: 1.8rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--ink);
  font-size: 0.82rem;
  font-weight: 720;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.primary-link span { color: var(--accent); font-size: 1.2rem; }

.chapter-route { max-width: 76rem; margin: 3rem auto 0; padding-top: 4rem; border-top: 1px solid var(--line); }
.chapter-route > h2 { font-size: clamp(2.5rem, 5vw, 4.8rem); }
.chapter-route-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 2.5rem; margin-top: 2.5rem; }
.chapter-route-link {
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  gap: 0.75rem;
  padding: 1.25rem 0;
  border-top: 1px solid var(--line);
}
.chapter-route-link > span { color: var(--accent); font-size: 0.72rem; }
.chapter-route-link h2 { margin: 0; font-family: var(--serif); font-size: clamp(1.2rem, 1rem + 0.55vw, 1.65rem); font-weight: 500; line-height: 1.15; }
.chapter-route-link p { margin: 0.45rem 0 0; color: var(--muted); font-size: 0.85rem; line-height: 1.45; }

.book-dedication { max-width: 33rem; margin: 2rem 0 0; padding-left: 1.2rem; border-left: 1px solid var(--accent); color: var(--muted); font-family: var(--serif); font-size: clamp(1.15rem, 1rem + 0.45vw, 1.45rem); font-style: italic; line-height: 1.45; }
.complete-book-reader { max-width: 76rem; margin: 4rem auto 0; padding-top: clamp(3rem, 7vw, 6rem); border-top: 1px solid var(--line); }
.complete-book-reader-intro { display: grid; grid-template-columns: minmax(18rem, 1.1fr) minmax(16rem, 0.9fr); gap: clamp(2rem, 8vw, 7rem); align-items: end; }
.complete-book-reader-intro h2 { max-width: 12ch; margin: 0.8rem 0 0; font-family: var(--serif); font-size: clamp(3rem, 6vw, 6.2rem); font-weight: 400; letter-spacing: -0.05em; line-height: 0.92; text-wrap: balance; }
.complete-book-reader-intro > p { max-width: 34rem; margin: 0; color: var(--muted); font-size: clamp(1rem, 1rem + 0.25vw, 1.2rem); line-height: 1.6; }
.complete-book-jump { display: grid; grid-template-columns: repeat(auto-fit, minmax(10rem, 1fr)); margin-top: clamp(2.5rem, 5vw, 4rem); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.complete-book-jump a { min-width: 0; padding: 1rem 0.8rem 1.1rem 0; border-right: 1px solid var(--line); }
.complete-book-jump a:last-child { border-right: 0; padding-right: 0; padding-left: 0.8rem; }
.complete-book-jump span { display: block; margin-bottom: 0.6rem; color: var(--accent); font-family: var(--mono); font-size: 0.64rem; }
.complete-book-jump strong { display: block; overflow-wrap: anywhere; font-family: var(--serif); font-size: clamp(0.95rem, 1.4vw, 1.25rem); font-weight: 500; line-height: 1.12; }
.complete-book-chapter { display: grid; grid-template-columns: minmax(4rem, 8rem) minmax(0, 1fr); gap: clamp(1.5rem, 5vw, 5rem); padding: clamp(4rem, 9vw, 8rem) 0; border-bottom: 1px solid var(--line); scroll-margin-top: 2rem; }
.complete-book-chapter-marker { display: flex; gap: 0.8rem; align-items: flex-start; color: var(--accent); font-family: var(--mono); font-size: 0.66rem; }
.complete-book-chapter-marker i { display: block; flex: 1; height: 1px; margin-top: 0.45rem; background: color-mix(in srgb, var(--accent) 44%, transparent); }
.complete-book-chapter-copy { min-width: 0; }
.complete-book-chapter-copy > header h2 { max-width: 15ch; margin: 0.7rem 0 1rem; font-family: var(--serif); font-size: clamp(2.8rem, 6vw, 5.8rem); font-weight: 400; letter-spacing: -0.05em; line-height: 0.94; text-wrap: balance; }
.complete-book-chapter-copy > header > p:last-child { max-width: 44rem; margin: 0; color: var(--muted); font-size: clamp(1.05rem, 1rem + 0.35vw, 1.3rem); line-height: 1.55; }
.complete-book-chapter-visual { overflow: hidden; margin: clamp(2rem, 5vw, 3.5rem) 0 0; border: 1px solid var(--line); border-radius: 0.2rem; background: #e7e0d2; box-shadow: 0 1.2rem 3rem rgba(31, 42, 72, 0.1); }
.complete-book-chapter-visual img { display: block; width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.complete-book-body { width: min(44rem, 100%); }
.complete-book-body .book-section { padding: clamp(2rem, 5vw, 3.5rem) 0 1rem; border-bottom: 0; }
.complete-book-body .book-section > h2:first-child,
.complete-book-body .book-section > h3:first-child { display: none; }
.complete-book-body .book-section h3 { font-size: clamp(1.5rem, 2.5vw, 2.15rem); }
.complete-book-chapter-link { display: inline-flex; gap: 1rem; align-items: center; margin-top: 1rem; padding: 0.8rem 0; border-bottom: 1px solid var(--ink); font-size: 0.72rem; font-weight: 720; letter-spacing: 0.08em; text-transform: uppercase; }
.complete-book-chapter-link span { color: var(--accent); font-size: 1rem; }

.chapter-stage { padding: clamp(2rem, 6vw, 5rem) clamp(1rem, 6vw, 6rem) 5rem; }
.source-document-stage { padding: clamp(2rem, 6vw, 5rem) clamp(1rem, 6vw, 6rem) 5rem; }
.source-document .chapter-intro h1 { max-width: 18ch; }
.reading-page { width: min(57rem, 100%); margin: 0 auto; }
.chapter-intro { padding: clamp(2.5rem, 7vw, 6rem) 0 3rem; border-bottom: 1px solid var(--line); }
.chapter-intro h1 { max-width: 15ch; margin: 1rem 0; font-family: var(--serif); font-size: clamp(3.2rem, 8vw, 7rem); font-weight: 400; letter-spacing: -0.055em; line-height: 0.95; text-wrap: balance; }
.chapter-stage[data-book-id="about-me"] .chapter-intro h1 { max-width: 18ch; font-size: clamp(3rem, 6vw, 5.8rem); }
.chapter-lead { max-width: 44rem; margin: 1.4rem 0 0; color: var(--muted); font-size: clamp(1.12rem, 1rem + 0.6vw, 1.55rem); line-height: 1.52; }
.chapter-illustration {
  overflow: hidden;
  margin: clamp(2rem, 5vw, 4rem) 0 0;
  border: 1px solid var(--line);
  border-radius: 0.2rem;
  background: #e7e0d2;
  box-shadow: 0 1.2rem 3rem rgba(31, 42, 72, 0.12);
}
.chapter-illustration img { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.responsive-illustration picture { display: block; width: 100%; }
.responsive-illustration img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: auto;
  object-fit: contain;
}
.responsive-illustration figcaption {
  padding: 0.8rem 1rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.5;
}
.illustration-long-description {
  padding: 1rem clamp(1rem, 2.5vw, 1.5rem) 1.2rem;
  border-top: 1px solid var(--line);
  color: var(--ink);
  background: rgba(255, 253, 247, 0.76);
  font-size: 0.88rem;
  line-height: 1.62;
}
.illustration-long-description p { max-width: 74ch; margin: 0; }
.illustration-long-description p + p { margin-top: 0.45rem; }
.illustration-long-description-label {
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.chapter-stage[data-book-id="who-owns-the-future-you"] .chapter-illustration,
.book-index-stage[data-book-id="who-owns-the-future-you"] .complete-book-chapter-visual {
  background: #f7f5ef;
}
.book-sections { padding-top: 1rem; }
.book-section { padding: clamp(2rem, 5vw, 4rem) 0; border-bottom: 1px solid var(--line); }
.book-section > :first-child { margin-top: 0; }
.book-section h2 { margin: 2.6rem 0 1rem; font-family: var(--serif); font-size: clamp(2rem, 4vw, 3.3rem); font-weight: 450; letter-spacing: -0.035em; line-height: 1.08; }
.book-section h3 { margin-top: 2.2rem; font-family: var(--serif); font-size: clamp(1.45rem, 2.5vw, 2.1rem); font-weight: 500; }
.book-section h4 { margin-top: 1.8rem; font-size: 1.1rem; }
.book-section p, .book-section li { max-width: 70ch; }
.book-section blockquote { margin: 2rem 0; padding: 0.2rem 0 0.2rem 1.5rem; border-left: 2px solid var(--accent); color: var(--muted); font-family: var(--serif); font-size: 1.15em; }
.table-scroll {
  max-width: 100%;
  margin: 2rem 0;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  border: 1px solid var(--line);
  background: rgba(255, 253, 247, 0.58);
}
.book-section table { width: 100%; min-width: 44rem; border-collapse: collapse; }
.book-section th,
.book-section td { padding: 0.85rem 0.9rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.book-section th { color: var(--ink); background: var(--accent-soft); font-size: 0.76rem; letter-spacing: 0.04em; }
.book-section td { color: var(--muted); font-size: 0.86rem; line-height: 1.5; }
.book-section tbody tr:last-child td { border-bottom: 0; }
.wikilink { color: var(--accent); font-weight: 650; }
.chapter-source-notes { margin-top: 4rem; padding: 2rem 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.chapter-source-notes ol { margin: 1.2rem 0 0; padding: 0; list-style: none; }
.chapter-source-notes li { display: flex; justify-content: space-between; gap: 1rem; padding: 0.65rem 0; border-top: 1px solid color-mix(in srgb, var(--line) 65%, transparent); color: var(--muted); font-size: 0.78rem; }
.chapter-source-notes li a { overflow-wrap: anywhere; color: var(--ink); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--accent) 38%, transparent); text-underline-offset: 0.2em; }
.chapter-source-notes li span:last-child { letter-spacing: 0.08em; text-transform: capitalize; }
.chapter-nav { display: grid; grid-template-columns: 1fr auto 1fr; gap: 1rem; margin-top: 4rem; }
.chapter-nav a { padding: 1rem 0; border-top: 1px solid var(--line); font-family: var(--serif); line-height: 1.25; }
.chapter-nav a:last-child { text-align: right; }
.chapter-nav .contents { padding-inline: 1rem; text-align: center; font-family: var(--sans); font-size: 0.72rem; font-weight: 750; letter-spacing: 0.1em; text-transform: uppercase; }

.progress { position: fixed; z-index: 20; top: 0; left: 0; width: var(--reading-progress, 0%); height: 2px; background: var(--accent); pointer-events: none; }
.language-switch {
  position: absolute;
  z-index: 30;
  top: 1rem;
  right: 1rem;
  padding: 0.25rem 0;
  border: 0;
  border-radius: 0;
  color: var(--ink);
  background: transparent;
  box-shadow: none;
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* Library renderer shares the reading-desk primitives. */
.library-stage { padding: clamp(2rem, 3vw, 3rem) clamp(1.5rem, 4vw, 4.5rem) 7rem; }
.library-intro { max-width: 76rem; margin: 0 auto clamp(1.35rem, 2vw, 2rem); }
.library-intro h1 { max-width: 16ch; }
.library-intro h1 { font-size: clamp(4.5rem, 6.8vw, 7.2rem); }
.library-intro p { max-width: 42rem; margin-bottom: 0; color: var(--muted); font-size: 1.04rem; }
.library-shelf { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(1rem, 1.7vw, 1.6rem); max-width: 76rem; margin: 0 auto; align-items: stretch; }
.shelf-book {
  --shelf-book-ratio: 0.72;
  --book-accent: var(--accent);
  position: relative;
  display: flex;
  flex-direction: column;
  width: 100%;
  height: auto;
  aspect-ratio: var(--shelf-book-ratio);
  min-height: 0;
  padding: 1.25rem 1.2rem 1.15rem 1.45rem;
  border: 1px solid rgba(0,0,0,.2);
  border-radius: 0.15rem 0.55rem 0.55rem 0.15rem;
  color: white;
  background-color: var(--book-accent);
  background-image: var(--cover-image);
  background-size: cover;
  box-shadow: 0.7rem 1rem 1.8rem rgba(47, 38, 25, 0.2), inset 0.22rem 0 0 rgba(255,255,255,.12);
  transform: perspective(60rem) rotateY(-3deg);
  transform-origin: left;
  transition: transform 260ms ease, box-shadow 260ms ease;
}
.shelf-book::before { position: absolute; inset: 0 auto 0 0.95rem; width: 1px; background: rgba(255,255,255,.24); content: ""; }
.shelf-book::after { position: absolute; z-index: -1; right: -.42rem; bottom: -.34rem; left: .35rem; height: .45rem; border-radius: 0 0 .3rem .15rem; background: #e8e0d2; box-shadow: 0 .2rem .35rem rgba(47,38,25,.18); content: ""; }
.shelf-book:hover { color: white; transform: perspective(60rem) rotateY(0) translateY(-0.6rem); box-shadow: 1rem 1.8rem 3.4rem rgba(25,35,60,.22); }
.shelf-book > span { color: rgba(255,255,255,.76); font-family: var(--mono); font-size: 0.62rem; letter-spacing: 0.1em; text-transform: uppercase; }
.shelf-book h2 { margin: 3rem 0 0; font-family: var(--serif); font-size: clamp(2.2rem, 2.55vw, 3.15rem); font-weight: 400; letter-spacing: -0.025em; line-height: 0.88; overflow-wrap: normal; word-break: normal; }
.shelf-book[data-book-id="who-owns-the-future-you"] h2 { font-size: clamp(1.9rem, 2.25vw, 2.75rem); }
.shelf-book p { display: none; }
.shelf-book b { margin-top: auto; color: rgba(255,255,255,.72); font-family: var(--mono); font-size: .6rem; font-weight: 400; letter-spacing: .1em; text-transform: uppercase; }
.shelf-book-protected {
  display: block;
  padding: 0;
}
.protected-book-trigger { display: flex; width: 100%; height: 100%; min-width: 0; padding: 1.25rem 1.2rem 1.15rem 1.45rem; border: 0; color: inherit; background: transparent; flex-direction: column; text-align: left; cursor: pointer; }
.protected-book-trigger > span { color: rgba(255,255,255,.76); font-family: var(--mono); font-size: .62rem; letter-spacing: .1em; text-transform: uppercase; }
.protected-book-trigger h2 { margin: 3rem 0 0; }
.protected-book-trigger b { margin-top: auto; }
.protected-book-trigger em { margin-top: .65rem; color: rgba(255,255,255,.7); font-family: var(--mono); font-size: .58rem; font-style: normal; letter-spacing: .08em; text-transform: uppercase; }
.book-access-dialog { width: min(32rem, calc(100vw - 2rem)); padding: clamp(1.4rem, 4vw, 2.4rem); border: 1px solid rgba(23,23,20,.2); border-radius: .2rem; color: var(--ink); background: #f4efe5 url("paper.jpg"); box-shadow: 0 2rem 6rem rgba(12,18,30,.35); }
.book-access-dialog::backdrop { background: rgba(12,18,30,.58); backdrop-filter: blur(6px); }
.book-access-dialog h2 { margin: .7rem 0 1.5rem; font-family: var(--serif); font-size: clamp(2.4rem, 8vw, 4.2rem); font-weight: 400; line-height: .9; }
.book-access-close { position: absolute; top: .8rem; right: .8rem; padding: .45rem .6rem; border: 0; background: transparent; color: var(--muted); font-family: var(--mono); font-size: .62rem; letter-spacing: .08em; text-transform: uppercase; cursor: pointer; }
.family-unlock { min-width: 0; padding: 1rem; border: 1px solid rgba(255,255,255,.24); background: rgba(15,24,37,.2); backdrop-filter: blur(7px); }
.book-access-dialog .family-unlock { border-color: var(--line); background: rgba(255,255,255,.42); }
.book-access-dialog .family-unlock label { color: var(--muted); }
.family-unlock label { display: block; margin-bottom: .65rem; color: rgba(255,255,255,.76); font-family: var(--mono); font-size: .62rem; letter-spacing: .1em; text-transform: uppercase; }
.family-unlock > div { display: grid; grid-template-columns: minmax(0, 1fr) auto; }
.family-unlock input { min-width: 0; height: 3.1rem; padding: 0 1rem; border: 1px solid rgba(255,255,255,.36); border-right: 0; border-radius: 0; outline: 0; background: rgba(255,255,255,.93); color: var(--ink); font: 600 1rem/1 var(--sans); letter-spacing: .12em; }
.family-unlock input:focus { box-shadow: inset 0 0 0 2px rgba(176,139,82,.7); }
.family-unlock button { height: 3.1rem; padding: 0 1.2rem; border: 1px solid rgba(255,255,255,.7); background: #f4efe5; color: #17283a; font: 700 .68rem/1 var(--sans); letter-spacing: .08em; text-transform: uppercase; cursor: pointer; }
.family-unlock button:hover { background: white; }
.family-unlock button span { margin-left: .5rem; color: var(--book-accent); }

.atlas-reading-preview {
  display: grid;
  grid-template-columns: minmax(13rem, 17rem) minmax(0, 1fr);
  gap: clamp(1.3rem, 2.4vw, 2.3rem);
  max-width: 76rem;
  margin: clamp(1rem, 1.5vw, 1.4rem) auto 0;
  padding: 1.1rem;
  border: 1px solid rgba(23,23,20,.18);
  background: rgba(46, 44, 40, 0.94);
  box-shadow: 0 1.8rem 4rem rgba(47,38,25,.2);
}
.atlas-preview-index {
  padding: 1.15rem 1rem 1rem;
  border: 1px solid rgba(255,255,255,.17);
  color: #f4efe5;
}
.atlas-preview-index .section-kicker { color: rgba(255,255,255,.54); }
.atlas-preview-index h2 { margin: 1.3rem 0 .65rem; font-family: var(--serif); font-size: 3.2rem; font-weight: 400; line-height: .9; }
.atlas-preview-index > p:not(.section-kicker) { color: rgba(255,255,255,.63); font-size: .75rem; line-height: 1.5; }
.atlas-preview-index nav { margin-top: 2rem; border-top: 1px solid rgba(255,255,255,.2); }
.atlas-preview-index nav a { display: grid; grid-template-columns: 1.75rem 1fr; gap: .4rem; padding: .75rem 0; border-bottom: 1px solid rgba(255,255,255,.16); color: rgba(255,255,255,.78); }
.atlas-preview-index nav span { font-family: var(--mono); font-size: .58rem; }
.atlas-preview-index nav strong { font-family: var(--serif); font-size: 1.05rem; font-weight: 400; line-height: 1.05; }
.atlas-preview-index .primary-link { margin-top: 2.2rem; border-color: rgba(255,255,255,.55); color: #fff; font-size: .65rem; }
.atlas-open-spread {
  display: grid;
  grid-template-columns: minmax(12rem, .58fr) minmax(22rem, 1.42fr);
  min-width: 0;
  color: var(--ink);
  transform: perspective(90rem) rotateX(1.2deg) rotateY(-1deg);
  transform-origin: center bottom;
  transition: transform 350ms ease, filter 350ms ease;
}
.atlas-open-spread:hover { color: var(--ink); filter: brightness(1.02); transform: perspective(90rem) rotateX(0) rotateY(0) translateY(-.25rem); }
.atlas-paper-page {
  position: relative;
  min-width: 0;
  min-height: 31rem;
  margin: 0;
  overflow: hidden;
  border: 1px solid rgba(23,23,20,.17);
  background-color: #f5f0e6;
  background-image: url("paper.jpg");
  background-size: 70rem auto;
  box-shadow: .6rem 1.1rem 2.6rem rgba(0,0,0,.2);
}
.atlas-paper-copy { overflow: visible; padding: clamp(2rem, 4vw, 4rem) clamp(1.4rem, 3vw, 3rem); border-radius: 0 .25rem .25rem 0; }
.atlas-paper-copy::after { position: absolute; top: 0; bottom: 0; left: 0; width: 1px; background: rgba(23,23,20,.16); content: ""; }
.atlas-paper-copy > span { display: block; margin-top: 2rem; color: var(--accent); font-family: var(--mono); font-size: .7rem; }
.atlas-paper-copy h3 { max-width: none; margin: .8rem 0 1.2rem; font-family: var(--serif); font-size: clamp(2.4rem, 3.6vw, 4rem); font-weight: 400; line-height: .88; }
.atlas-paper-copy > p:not(.section-kicker) { max-width: 27ch; color: var(--muted); font-size: .76rem; line-height: 1.5; }
.atlas-preview-cover { overflow: hidden; padding: 0; border-radius: .25rem 0 0 .25rem; background: #152c47; }
.atlas-preview-cover img { display: block; width: 100%; height: 100%; object-fit: cover; }
.atlas-preview-cover figcaption { position: absolute; inset: 0; display: flex; padding: 1rem; color: white; flex-direction: column; background: rgba(8,20,38,.12); }
.atlas-preview-cover figcaption span { font-family: var(--mono); font-size: .58rem; letter-spacing: .08em; }
.atlas-preview-cover figcaption strong { margin: auto 0; font-family: var(--serif); font-size: clamp(1.5rem, 2.3vw, 2.4rem); font-weight: 400; line-height: .9; }
.library-book-stage { display: grid; grid-template-columns: minmax(15rem, 22rem) minmax(16rem, 1fr); gap: clamp(3rem, 8vw, 9rem); align-items: center; min-height: 78vh; max-width: 76rem; margin: 0 auto; }
.book-actions { display: grid; gap: 0; margin-top: 2.2rem; border-top: 1px solid var(--line); }
.book-action { display: flex; justify-content: space-between; gap: 1rem; padding: 1rem 0; border-bottom: 1px solid var(--line); font-weight: 620; }

@keyframes stage-in {
  from { opacity: 0; transform: translateY(0.8rem); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1080px) {
  .library-shelf { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .atlas-reading-preview { grid-template-columns: 1fr; }
  .atlas-preview-index { display: grid; grid-template-columns: 1fr 1fr; gap: 0 2rem; }
  .atlas-preview-index nav { grid-column: 2; grid-row: 1 / span 4; margin-top: 0; }
  .atlas-preview-index .primary-link { align-self: end; width: fit-content; }
}

@media (max-width: 860px) {
  .language-switch { top: .8rem; right: .85rem; bottom: auto; }
  .reader-layout { display: block; }
  .reader-rail {
    position: sticky;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: .65rem;
    align-items: center;
    height: auto;
    padding: .65rem 5.8rem .65rem 1rem;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .reader-wordmark { display: none; }
  .reader-book-identity { display: block; min-width: 0; margin: 0; }
  .reader-book-identity > span { display: none; }
  .reader-brand { display: block; overflow: hidden; width: auto; font-size: 1rem; text-overflow: ellipsis; white-space: nowrap; }
  .rail-menu-toggle { display: grid; grid-template-columns: minmax(0, auto) auto; gap: .8rem; align-items: center; min-width: 0; padding: .55rem .1rem .55rem .8rem; border: 0; border-left: 1px solid var(--line); background: transparent; color: var(--ink); cursor: pointer; }
  .rail-menu-toggle span { overflow: hidden; max-width: 9rem; font-family: var(--serif); font-size: 1rem; text-overflow: ellipsis; white-space: nowrap; }
  .rail-menu-toggle strong { color: var(--accent); font-family: var(--mono); font-size: .62rem; letter-spacing: .08em; text-transform: uppercase; }
  .rail-menu-toggle strong::before { content: "+ "; }
  .reader-rail.is-menu-open .rail-menu-toggle strong::before { content: "− "; }
  .rail-chapters { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); max-height: min(70vh, 32rem); overflow-y: auto; border-top: 1px solid var(--line); box-shadow: 0 1rem 2rem rgba(47,38,25,.08); }
  .has-js .reader-rail:not(.is-menu-open) .rail-chapters { display: none; }
  .rail-chapter { grid-template-columns: 1.7rem minmax(0, 1fr); min-height: 3.8rem; padding: .8rem .7rem .8rem 0; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
  .rail-chapter:nth-child(even) { border-right: 0; padding-left: .7rem; }
  .rail-chapter::before { inset: auto 0 0 0; width: auto; height: 2px; }
  .book-hero, .library-book-stage { grid-template-columns: 1fr; min-height: auto; }
  .book-object { width: min(20rem, 100%); margin: 1rem auto 0; transform: none; }
  .book-opening { max-width: 42rem; }
  .chapter-route-list { grid-template-columns: 1fr; }
  .complete-book-reader-intro { grid-template-columns: 1fr; gap: 1.5rem; }
  .complete-book-jump { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .complete-book-jump a { border-bottom: 1px solid var(--line); }
  .complete-book-jump a:nth-child(even) { border-right: 0; padding-left: 0.8rem; }
  .complete-book-jump a:last-child { border-bottom: 0; }
  .complete-book-chapter { grid-template-columns: 1fr; gap: 1.2rem; }
  .complete-book-chapter-marker { width: min(8rem, 35%); }
  .library-stage, .book-index-stage { padding-top: 2rem; }
  .atlas-preview-index { display: block; }
  .atlas-preview-index nav { margin-top: 2rem; }
}

@media (max-width: 600px) {
  .book-index-stage, .library-stage { padding-inline: 1rem; }
  .chapter-stage { padding: 0 1rem 3rem; }
  .chapter-intro { padding-top: 3rem; }
  .chapter-intro h1 { font-size: clamp(2.8rem, 15vw, 4.7rem); }
  .chapter-route-link { grid-template-columns: 2rem minmax(0, 1fr); }
  .complete-book-reader { margin-top: 2rem; padding-top: 3rem; }
  .complete-book-reader-intro h2 { font-size: clamp(2.8rem, 14vw, 4.4rem); }
  .complete-book-jump { grid-template-columns: 1fr; }
  .complete-book-jump a, .complete-book-jump a:nth-child(even), .complete-book-jump a:last-child { padding: 0.85rem 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .complete-book-jump a:last-child { border-bottom: 0; }
  .complete-book-chapter { padding: 4rem 0; }
  .complete-book-chapter-copy > header h2 { font-size: clamp(2.7rem, 13vw, 4.2rem); }
  .complete-book-chapter-visual img { aspect-ratio: 4 / 3; }
  .complete-book-chapter-visual.responsive-illustration img { aspect-ratio: auto; }
  .library-shelf { grid-template-columns: 1fr 1fr; gap: 0.75rem; align-items: start; }
  .shelf-book { min-height: 0; padding: 1rem; align-self: start; }
  .shelf-book h2 { font-size: clamp(1.55rem, 7.2vw, 2.25rem); }
  .shelf-book[data-book-id="who-owns-the-future-you"] h2 { font-size: clamp(1.35rem, 6.2vw, 1.9rem); }
  .shelf-book-protected { padding: 0; }
  .protected-book-trigger { padding: 1rem; }
  .shelf-book h2, .protected-book-trigger h2 { margin-top: 2rem; }
  .shelf-book[data-book-id="pressure-vessel-solver"] h2 { font-size: clamp(1.4rem, 6.5vw, 2rem); }
  .shelf-book p { display: none; }
  .atlas-reading-preview { margin-top: 2rem; padding: .55rem; }
  .atlas-preview-index { padding: 1rem; }
  .atlas-preview-index h2 { margin: .7rem 0 .4rem; font-size: 2.35rem; }
  .atlas-preview-index > p:not(.section-kicker) { display: none; }
  .atlas-preview-index nav { margin-top: .8rem; }
  .atlas-preview-index nav a { padding: .55rem 0; }
  .atlas-preview-index nav a:nth-child(n+2) { display: none; }
  .atlas-preview-index .primary-link { margin-top: .85rem; }
  .atlas-open-spread { grid-template-columns: minmax(7.5rem, .72fr) minmax(0, 1.28fr); align-items: stretch; transform: none; }
  .atlas-paper-page { min-height: 0; }
  .atlas-preview-cover { height: 100%; aspect-ratio: auto; border-radius: .2rem 0 0 .2rem; }
  .atlas-paper-copy { min-width: 0; padding: 1.15rem 1rem; border-radius: 0 .2rem .2rem 0; }
  .atlas-paper-copy > span { margin-top: 1.2rem; }
  .atlas-paper-copy h3 { margin: .55rem 0 .8rem; font-size: clamp(1.85rem, 8.4vw, 2.65rem); overflow-wrap: normal; }
  .atlas-paper-copy > p:not(.section-kicker) { margin-bottom: 0; font-size: .7rem; line-height: 1.42; }
  .family-unlock { padding: .75rem; }
  .family-unlock > div { grid-template-columns: 1fr; }
  .family-unlock input { border-right: 1px solid rgba(255,255,255,.36); }
  .family-unlock button { width: 100%; margin-top: .55rem; }
  .chapter-nav { grid-template-columns: 1fr 1fr; }
  .chapter-nav .contents { grid-column: 1 / -1; grid-row: 1; }
  .chapter-source-notes li { align-items: flex-start; }
  html[lang^="zh"] .library-intro h1 { font-size: clamp(3.35rem, 15vw, 4rem); line-height: 1.08; letter-spacing: -.02em; }
  html[lang^="zh"] :is(.book-opening h2, .chapter-route > h2, .chapter-intro h1, .complete-book-reader-intro h2, .complete-book-chapter-copy > header h2, .atlas-preview-index h2, .atlas-paper-copy h3) { line-height: 1.08; letter-spacing: -.015em; overflow-wrap: anywhere; }
  html[lang^="zh"] .shelf-book h2 { line-height: 1.02; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; transform: none !important; }
}

@media print {
  .reader-rail, .chapter-nav, .progress, .language-switch { display: none; }
  .reader-layout { display: block; }
  .chapter-stage { padding: 0; }
  body { background: white; }
  .book-section { break-inside: avoid; }
  .table-scroll { overflow: visible; border-color: #aaa; }
  .book-section table { min-width: 0; font-size: 9pt; }
  .responsive-illustration { break-inside: avoid; box-shadow: none; }
  .illustration-long-description { border-color: #aaa; color: #000; background: transparent; }
}