:root {
  --book-black: #0b0a08;
  --book-black-soft: #15120e;
  --book-ivory: #f2eadc;
  --book-paper: #e4dacb;
  --book-red: #b82018;
  --book-red-bright: #e13a27;
  --book-gold: #e7af2a;
  --book-muted: #8c8174;
  --book-line: rgba(242,234,220,.15);
  --book-shell: min(1160px, calc(100% - 48px));
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--book-black); background: var(--book-ivory); font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 16px; line-height: 1.65; -webkit-font-smoothing: antialiased; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; }
.book-shell { width: var(--book-shell); margin-inline: auto; }
.book-skip-link { position: fixed; z-index: 1000; top: 10px; left: 10px; padding: 10px 16px; color: var(--book-black); background: var(--book-gold); transform: translateY(-150%); }
.book-skip-link:focus { transform: none; }

.book-header { position: absolute; z-index: 20; inset: 0 0 auto; border-bottom: 1px solid var(--book-line); }
.book-header-inner { min-height: 86px; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.book-brand { display: inline-flex; align-items: center; gap: 11px; color: var(--book-ivory); text-decoration: none; }
.book-brand img { width: 34px; height: 47px; object-fit: contain; }
.book-brand > span { display: grid; gap: 4px; line-height: 1; }
.book-brand strong { font-size: 16px; letter-spacing: .07em; }
.book-brand small { color: var(--book-gold); font-size: 8px; font-weight: 800; letter-spacing: .35em; text-transform: uppercase; }
.book-back { padding: 10px 0; color: rgba(242,234,220,.72); font-size: 13px; font-weight: 700; text-decoration: none; }
.book-back:hover { color: var(--book-gold); }

.book-hero { position: relative; min-height: 880px; display: grid; align-items: center; overflow: hidden; color: var(--book-ivory); background: radial-gradient(circle at 75% 42%, rgba(184,32,24,.2), transparent 26%), linear-gradient(125deg, #080706 0%, #100d09 56%, #1a120d 100%); }
.book-hero::before { content: ""; position: absolute; inset: 0; opacity: .14; pointer-events: none; background-image: linear-gradient(rgba(231,175,42,.11) 1px, transparent 1px), linear-gradient(90deg, rgba(231,175,42,.11) 1px, transparent 1px); background-size: 76px 76px; mask-image: linear-gradient(to right, transparent 8%, black 72%, transparent); }
.book-hero::after { content: ""; position: absolute; width: 620px; height: 620px; right: -260px; bottom: -340px; border: 1px solid rgba(231,175,42,.18); border-radius: 50%; box-shadow: 0 0 0 90px rgba(231,175,42,.025), 0 0 0 180px rgba(231,175,42,.018); }
.book-hero-grid { position: relative; z-index: 2; display: grid; grid-template-columns: 1.06fr .94fr; gap: 76px; align-items: center; padding: 150px 0 80px; }
.book-overline { margin: 0 0 22px; color: var(--book-gold); font-size: 11px; font-weight: 900; letter-spacing: .2em; text-transform: uppercase; }
.book-overline--dark { color: var(--book-red); }
.book-hero h1 { max-width: 680px; margin: 0; font-family: Georgia, "Times New Roman", serif; font-size: clamp(58px, 7vw, 92px); font-weight: 500; line-height: .88; letter-spacing: -.06em; }
.book-hero h1 span { display: block; color: var(--book-red-bright); font-style: italic; }
.book-subtitle { max-width: 660px; margin: 30px 0 0; color: var(--book-ivory); font-family: Georgia, "Times New Roman", serif; font-size: 22px; line-height: 1.35; }
.book-intro { max-width: 650px; margin: 24px 0 0; color: rgba(242,234,220,.62); font-size: 16px; }
.book-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.book-button { min-height: 52px; display: inline-flex; align-items: center; justify-content: center; padding: 0 24px; border: 1px solid transparent; border-radius: 3px; font-size: 13px; font-weight: 850; letter-spacing: .04em; text-decoration: none; transition: transform .2s, background .2s, color .2s; }
.book-button:hover { transform: translateY(-2px); }
.book-button--primary { color: var(--book-ivory); background: var(--book-red); }
.book-button--primary:hover { background: var(--book-red-bright); }
.book-button--outline { color: var(--book-ivory); border-color: rgba(242,234,220,.32); }
.book-button--outline:hover { color: var(--book-black); background: var(--book-gold); border-color: var(--book-gold); }
.book-author-line { margin: 24px 0 0; color: rgba(242,234,220,.5); font-size: 13px; }
.book-author-line strong { color: var(--book-ivory); }
.book-cover-wrap { position: relative; margin: 0; background: transparent; }
.book-cover-halo { position: absolute; inset: 12% 5%; border-radius: 50%; background: rgba(184,32,24,.2); filter: blur(70px); }
.book-cover { position: relative; z-index: 1; width: min(100%, 540px); margin-inline: auto; background: transparent; filter: drop-shadow(0 42px 60px rgba(0,0,0,.55)); transform: rotate(1.5deg); }
.book-cover-carousel { position: relative; z-index: 1; margin-inline: auto; isolation: isolate; }
.book-cover-carousel--hero { width: min(100%, 540px); aspect-ratio: 1; }
.book-cover-carousel-track { position: absolute; inset: 0; }
.book-cover-carousel-slide { position: absolute; inset: 0; display: grid; place-items: center; margin: 0; visibility: hidden; opacity: 0; transform: translateX(12px); transition: opacity .38s ease, transform .38s ease, visibility .38s; }
.book-cover-carousel-slide.is-active { visibility: visible; opacity: 1; transform: none; }
.book-cover-carousel--hero .book-cover-carousel-slide img { width: auto; height: 100%; max-width: 100%; object-fit: contain; background: transparent; filter: drop-shadow(0 42px 60px rgba(0,0,0,.55)); transform: rotate(1.5deg); }
.book-cover-carousel--hero .book-cover-carousel-slide:not(:first-child) { align-items: start; padding-top: 28px; }
.book-cover-carousel--hero .book-cover-carousel-slide:not(:first-child) img { height: 64%; }
.book-cover-carousel-arrow { position: absolute; top: 50%; z-index: 4; width: 42px; height: 42px; display: grid; place-items: center; padding: 0 0 3px; border: 1px solid rgba(242,234,220,.32); border-radius: 50%; color: var(--book-ivory); background: rgba(11,10,8,.78); box-shadow: 0 12px 30px rgba(0,0,0,.28); font: inherit; font-size: 30px; line-height: 1; cursor: pointer; transform: translateY(-50%); transition: color .2s ease, border-color .2s ease, background .2s ease; }
.book-cover-carousel-arrow:hover, .book-cover-carousel-arrow:focus-visible { color: var(--book-black); border-color: var(--book-gold); background: var(--book-gold); }
.book-cover-carousel-arrow--prev { left: 8px; }
.book-cover-carousel-arrow--next { right: 8px; }
.book-cover-carousel-dots { position: absolute; left: 50%; bottom: 8px; z-index: 4; display: flex; gap: 7px; padding: 7px 9px; border-radius: 999px; background: rgba(11,10,8,.78); transform: translateX(-50%); }
.book-cover-carousel-dots button { width: 7px; height: 7px; padding: 0; border: 0; border-radius: 50%; background: rgba(242,234,220,.42); cursor: pointer; transition: width .2s ease, border-radius .2s ease, background .2s ease; }
.book-cover-carousel-dots button.is-active { width: 20px; border-radius: 999px; background: var(--book-gold); }
.book-cover-carousel:focus-visible { outline: 2px solid var(--book-gold); outline-offset: 5px; }
.book-cover-wrap figcaption { position: relative; z-index: 2; margin-top: 10px; color: rgba(242,234,220,.38); font-size: 10px; font-weight: 750; letter-spacing: .16em; text-align: center; text-transform: uppercase; }

.book-pillars { color: var(--book-ivory); background: var(--book-red); }
.book-pillars-grid { display: grid; grid-template-columns: repeat(3, 1fr); }
.book-pillars article { min-height: 135px; display: grid; grid-template-columns: auto 1fr; gap: 20px; align-items: center; padding: 30px 38px; border-right: 1px solid rgba(255,255,255,.2); }
.book-pillars article:last-child { border-right: 0; }
.book-pillars span { color: var(--book-gold); font-family: Georgia, serif; font-size: 14px; font-weight: 700; }
.book-pillars h2 { margin: 0; font-family: Georgia, serif; font-size: 20px; font-weight: 500; line-height: 1.25; }

.book-section { padding: 118px 0; }
.book-reading-grid { display: grid; grid-template-columns: .8fr 1.2fr; gap: 100px; align-items: start; }
.book-section-heading { position: sticky; top: 40px; }
.book-section-heading h2 { max-width: 450px; margin: 0; font-family: Georgia, serif; font-size: clamp(44px, 5vw, 66px); font-weight: 500; line-height: 1.03; letter-spacing: -.04em; }
.book-section-heading h2 em { color: var(--book-red); font-weight: 500; }
.book-reading-grid > .book-prose { padding-top: 40px; }
.book-prose { max-width: 700px; color: #50483f; font-family: Georgia, "Times New Roman", serif; font-size: 19px; line-height: 1.8; }
.book-prose p { margin: 0 0 28px; }
.book-prose strong { color: var(--book-black); }
.book-prose blockquote { margin: 52px 0 0; padding: 30px 0 30px 34px; color: var(--book-black); border-left: 4px solid var(--book-red); font-size: 23px; line-height: 1.55; }

.book-content { color: var(--book-ivory); background: radial-gradient(circle at 85% 12%, rgba(184,32,24,.2), transparent 25%), var(--book-black-soft); }
.book-content-heading { display: grid; grid-template-columns: .8fr 1.2fr; column-gap: 80px; align-items: start; margin-bottom: 54px; }
.book-content-heading .book-overline { grid-column: 1 / -1; }
.book-content-heading h2 { margin: 0; font-family: Georgia, serif; font-size: clamp(42px, 4.6vw, 62px); font-weight: 500; line-height: 1.05; }
.book-content-heading > p:last-child { max-width: 580px; margin: 0; color: rgba(242,234,220,.56); }
.book-topic-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.book-topic-grid article { min-height: 285px; padding: 30px; border: 1px solid var(--book-line); background: rgba(255,255,255,.025); }
.book-topic-grid article > span { width: 46px; height: 46px; display: grid; place-items: center; margin-bottom: 54px; color: var(--book-gold); border: 1px solid rgba(231,175,42,.35); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.book-topic-grid h3 { margin: 0 0 12px; font-family: Georgia, serif; font-size: 21px; font-weight: 500; }
.book-topic-grid p { margin: 0; color: rgba(242,234,220,.54); font-size: 14px; }

.book-application { background: var(--book-paper); }
.book-human-factor { padding: 116px 0; color: var(--book-ivory); text-align: center; background: var(--book-red); }
.book-human-factor span { display: block; height: 60px; color: var(--book-gold); font-family: Georgia, serif; font-size: 92px; line-height: 1; }
.book-human-factor p { max-width: 760px; margin: 16px auto 8px; font-family: Georgia, serif; font-size: clamp(24px, 3vw, 36px); line-height: 1.35; }
.book-human-factor h2 { margin: 0; color: var(--book-gold); font-family: Georgia, serif; font-size: clamp(40px, 5vw, 64px); font-style: italic; font-weight: 500; }

.book-download { padding: 100px 0; color: var(--book-ivory); background: var(--book-black); }
.book-download-grid { display: grid; grid-template-columns: 1fr 330px; gap: 90px; align-items: center; }
.book-download h2 { margin: 0; font-family: Georgia, serif; font-size: clamp(54px, 6vw, 82px); font-weight: 500; line-height: 1; }
.book-download p:not(.book-overline) { max-width: 560px; margin: 22px 0 30px; color: rgba(242,234,220,.58); font-size: 17px; }
.book-button--disabled { color: rgba(242,234,220,.46); border-color: rgba(242,234,220,.18); cursor: default; }
.book-button--disabled:hover { transform: none; }
.book-download small { display: block; margin-top: 13px; color: rgba(242,234,220,.34); }
.book-download-list { display: grid; grid-template-columns: 1fr; gap: 10px; max-width: 680px; }
.book-download-item { min-height: 82px; display: grid; grid-template-columns: 50px minmax(0, 1fr) auto; align-items: center; gap: 16px; padding: 14px 16px; color: var(--book-ivory); border: 1px solid rgba(242,234,220,.16); border-radius: 10px; background: rgba(255,255,255,.035); transition: border-color .2s, background .2s; }
.book-download-item:hover { border-color: rgba(231,175,42,.58); background: rgba(231,175,42,.055); }
.book-download-code { width: 50px; height: 50px; display: grid; place-items: center; color: var(--book-black); border-radius: 7px; background: var(--book-gold); font-size: 12px; font-weight: 900; letter-spacing: .1em; }
.book-download-info { min-width: 0; }
.book-download-info strong { display: block; font-family: Georgia, serif; font-size: 19px; font-weight: 500; }
.book-download-info small { margin-top: 5px; color: rgba(242,234,220,.46); font-size: 10px; font-weight: 700; letter-spacing: .06em; }
.book-download-button { min-height: 42px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 0 17px; color: var(--book-black); border: 1px solid var(--book-gold); border-radius: 999px; background: var(--book-gold); box-shadow: 0 8px 22px rgba(231,175,42,.14); font-size: 10px; font-weight: 900; letter-spacing: .08em; text-decoration: none; text-transform: uppercase; transition: background .2s, border-color .2s, transform .2s, box-shadow .2s; }
.book-download-button:hover, .book-download-button:focus-visible { color: var(--book-black); border-color: #f4c850; background: #f4c850; box-shadow: 0 10px 28px rgba(231,175,42,.26); transform: translateY(-2px); }
.book-download-note { margin-top: 16px; }
.book-download img { width: 330px; filter: drop-shadow(0 28px 40px rgba(0,0,0,.48)); transform: rotate(2deg) scale(1.26); transform-origin: center; }
.book-cover-carousel--download { width: 330px; height: 330px; margin-bottom: 78px; justify-self: center; }
.book-cover-carousel--download .book-cover-carousel-dots { bottom: -72px; }
.book-download .book-cover-carousel--download img { width: auto; height: 330px; max-width: 100%; object-fit: contain; filter: drop-shadow(0 28px 40px rgba(0,0,0,.48)); transform: rotate(2deg) scale(1.26); transform-origin: center; }

.book-footer { color: rgba(242,234,220,.5); background: #050504; }
.book-footer .book-shell { min-height: 92px; display: flex; align-items: center; justify-content: space-between; gap: 24px; border-top: 1px solid var(--book-line); font-size: 12px; }
.book-footer a { color: var(--book-gold); text-decoration: none; }

@media (max-width: 900px) {
  .book-hero-grid { grid-template-columns: 1fr; gap: 56px; padding-top: 150px; }
  .book-hero-copy { max-width: 760px; }
  .book-cover { width: min(100%, 520px); }
  .book-cover-carousel--hero { width: min(100%, 520px); }
  .book-reading-grid { grid-template-columns: 1fr; gap: 46px; }
  .book-reading-grid > .book-prose { padding-top: 0; }
  .book-section-heading { position: static; }
  .book-content-heading { grid-template-columns: 1fr; gap: 20px; }
  .book-topic-grid { grid-template-columns: repeat(2, 1fr); }
  .book-download-grid { grid-template-columns: 1fr 260px; gap: 50px; }
}

@media (max-width: 620px) {
  :root { --book-shell: min(100% - 28px, 1160px); }
  .book-header-inner { min-height: 72px; }
  .book-brand img { width: 29px; height: 40px; }
  .book-brand strong { font-size: 14px; }
  .book-back { font-size: 12px; }
  .book-hero { min-height: auto; }
  .book-hero-grid { gap: 42px; padding: 118px 0 62px; }
  .book-hero h1 { font-size: clamp(48px, 16vw, 66px); }
  .book-subtitle { font-size: 19px; }
  .book-actions, .book-actions .book-button { width: 100%; }
  .book-pillars-grid { grid-template-columns: 1fr; }
  .book-pillars article { min-height: 100px; border-right: 0; border-bottom: 1px solid rgba(255,255,255,.2); }
  .book-pillars article:last-child { border-bottom: 0; }
  .book-section { padding: 78px 0; }
  .book-prose { font-size: 17px; }
  .book-prose blockquote { padding-left: 23px; font-size: 20px; }
  .book-topic-grid { grid-template-columns: 1fr; }
  .book-topic-grid article { min-height: 230px; }
  .book-topic-grid article > span { margin-bottom: 38px; }
  .book-human-factor { padding: 82px 0; }
  .book-download { padding: 78px 0; }
  .book-download-grid { grid-template-columns: 1fr; gap: 50px; }
  .book-download-item { grid-template-columns: 44px minmax(0, 1fr); gap: 13px; }
  .book-download-code { width: 44px; height: 44px; }
  .book-download-button { grid-column: 2; width: fit-content; }
  .book-download img { width: min(100%, 300px); margin-inline: auto; transform: rotate(2deg) scale(1.14); }
  .book-cover-carousel--download { width: min(100%, 300px); height: auto; aspect-ratio: 1; margin: 0 auto 66px; }
  .book-cover-carousel--download .book-cover-carousel-dots { bottom: -58px; }
  .book-download .book-cover-carousel--download img { width: auto; height: 100%; max-width: 100%; transform: rotate(2deg) scale(1.14); }
  .book-cover-carousel-arrow { width: 38px; height: 38px; }
  .book-footer .book-shell { align-items: flex-start; flex-direction: column; justify-content: center; gap: 6px; }
}

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