:root {
  --ink: #111827;
  --muted: #536071;
  --line: #d7dde6;
  --paper: #f8fafc;
  --panel: #ffffff;
  --forest: #0e4a3a;
  --brick: #9b2f28;
  --signal: #1d4ed8;
  --amber: #b45309;
  --violet: #6d28d9;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
  letter-spacing: 0;
}

body {
  margin: 0;
  min-height: 100vh;
}

a {
  color: inherit;
}

.shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 2;
}

.nav {
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  font-size: 14px;
  font-weight: 800;
  text-transform: uppercase;
}

.navlinks {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--muted);
  font-size: 14px;
}

.navlinks a {
  text-decoration: none;
}

.hero {
  max-width: 1180px;
  width: 100%;
  margin: 0 auto;
  padding: 56px 22px 26px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.95fr);
  gap: 44px;
  align-items: center;
}

.hero-copy {
  min-width: 0;
}

.eyebrow {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
  margin-bottom: 12px;
}

h1 {
  margin: 0;
  font-size: clamp(40px, 7vw, 78px);
  line-height: 0.98;
  max-width: 760px;
}

h2 {
  margin: 0 0 16px;
  font-size: 28px;
  line-height: 1.15;
}

h3 {
  margin: 0;
  font-size: 18px;
  line-height: 1.25;
}

p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.lead {
  margin-top: 20px;
  max-width: 680px;
  font-size: 20px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 17px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  font-weight: 800;
  font-size: 15px;
  border-radius: 7px;
}

.button.secondary {
  background: transparent;
  color: var(--ink);
}

.visual {
  min-height: 420px;
  display: grid;
  place-items: center;
  border-left: 1px solid var(--line);
  padding-left: 34px;
}

.book-focus {
  width: min(330px, 82vw);
  display: grid;
  gap: 16px;
}

.cover {
  width: 100%;
  aspect-ratio: 0.68;
  border-radius: 6px;
  border: 1px solid rgba(17, 24, 39, 0.2);
  background: linear-gradient(135deg, #101820, #394b59);
  box-shadow: 0 22px 45px rgba(17, 24, 39, 0.22);
  overflow: hidden;
  object-fit: cover;
}

.cover-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  width: min(560px, 100%);
}

.cover-grid .cover {
  box-shadow: 0 12px 24px rgba(17, 24, 39, 0.16);
}

.project-visual {
  width: min(520px, 100%);
  min-height: 330px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(90deg, rgba(17, 24, 39, 0.05) 1px, transparent 1px),
    linear-gradient(rgba(17, 24, 39, 0.05) 1px, transparent 1px),
    #fff;
  background-size: 34px 34px;
  padding: 22px;
  display: grid;
  align-content: center;
  gap: 12px;
}

.node {
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff;
  padding: 12px 14px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 14px;
  font-weight: 800;
  box-shadow: 0 8px 18px rgba(17, 24, 39, 0.08);
}

.node span {
  color: var(--muted);
  font-weight: 700;
}

.band {
  width: 100%;
  border-top: 1px solid var(--line);
  padding: 34px 22px;
}

.inner {
  max-width: 1180px;
  margin: 0 auto;
}

.catalog {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.book-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  padding: 14px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 14px;
  min-width: 0;
}

.book-card .cover {
  box-shadow: none;
}

.meta {
  display: grid;
  gap: 8px;
}

.meta p {
  font-size: 14px;
}

.tagline {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.pill {
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  padding: 6px 10px;
  font-size: 13px;
  font-weight: 800;
  background: #fff;
}

.split {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.plain-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
  background: #fff;
  min-height: 150px;
}

.plain-card p {
  margin-top: 10px;
  font-size: 15px;
}

.book-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid rgba(14, 74, 58, 0.18);
  background: rgba(14, 74, 58, 0.08);
  color: var(--forest);
  font-size: 13px;
  font-weight: 800;
}

.book-hero h1 {
  max-width: 820px;
}

.book-hero .lead {
  max-width: 720px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 28px;
}

.metric {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.85);
  padding: 16px;
  min-width: 0;
}

.metric strong {
  display: block;
  font-size: 15px;
  margin-bottom: 6px;
}

.metric span {
  display: block;
  color: var(--muted);
  font-size: 14px;
}

.book-showcase {
  width: min(420px, 100%);
  display: grid;
  gap: 16px;
}

.book-frame {
  position: relative;
  border: 1px solid rgba(14, 74, 58, 0.14);
  border-radius: 14px;
  padding: 22px;
  background:
    radial-gradient(circle at top left, rgba(180, 83, 9, 0.14), transparent 34%),
    linear-gradient(160deg, rgba(14, 74, 58, 0.08), rgba(17, 24, 39, 0.02) 65%, #ffffff 100%);
  box-shadow: 0 22px 48px rgba(17, 24, 39, 0.14);
}

.book-frame .cover {
  display: block;
  width: 100%;
  max-width: 290px;
  margin: 0 auto;
  aspect-ratio: 0.68;
  border-radius: 12px;
  border-color: rgba(17, 24, 39, 0.16);
  box-shadow: 0 24px 48px rgba(17, 24, 39, 0.24);
}

.detail-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 18px;
  display: grid;
  gap: 12px;
  box-shadow: 0 14px 28px rgba(17, 24, 39, 0.08);
}

.detail-card h3 {
  font-size: 17px;
}

.detail-card p {
  font-size: 15px;
}

.detail-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.detail-meta div {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: var(--paper);
}

.detail-meta strong {
  display: block;
  font-size: 12px;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 5px;
}

.detail-meta span {
  display: block;
  font-size: 14px;
  font-weight: 800;
  color: var(--ink);
}

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.chapter-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 20px;
  min-width: 0;
}

.chapter-card p {
  margin-top: 10px;
  font-size: 15px;
}

.chapter-card ul {
  margin: 12px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 15px;
}

.chapter-card li + li {
  margin-top: 6px;
}

.cta-band {
  background:
    radial-gradient(circle at top left, rgba(14, 74, 58, 0.08), transparent 42%),
    linear-gradient(180deg, rgba(180, 83, 9, 0.06), rgba(255, 255, 255, 0));
}

.cta-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.cta-copy {
  display: grid;
  gap: 10px;
  max-width: 720px;
}

.footer {
  margin-top: auto;
  border-top: 1px solid var(--line);
  padding: 22px;
  color: var(--muted);
  font-size: 14px;
}

.footer .inner {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.theme-green .button { background: var(--forest); border-color: var(--forest); }
.theme-red .button { background: var(--brick); border-color: var(--brick); }
.theme-blue .button { background: var(--signal); border-color: var(--signal); }
.theme-amber .button { background: var(--amber); border-color: var(--amber); }
.theme-violet .button { background: var(--violet); border-color: var(--violet); }

@media (max-width: 920px) {
  .hero {
    grid-template-columns: 1fr;
    padding-top: 40px;
  }

  .visual {
    min-height: 0;
    border-left: 0;
    border-top: 1px solid var(--line);
    padding: 28px 0 0;
  }

  .catalog {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .split {
    grid-template-columns: 1fr;
  }

  .metrics {
    grid-template-columns: 1fr;
  }

  .chapter-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 620px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .navlinks {
    flex-wrap: wrap;
  }

  .hero {
    padding-left: 18px;
    padding-right: 18px;
  }

  .band {
    padding-left: 18px;
    padding-right: 18px;
  }

  .catalog {
    grid-template-columns: 1fr;
  }

  .cover-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .detail-meta {
    grid-template-columns: 1fr;
  }
}