:root {
  --ink: #111111;
  --muted: rgba(17, 17, 17, 0.64);
  --line: rgba(17, 17, 17, 0.08);
  --paper: #f4efe7;
  --panel: rgba(255, 255, 255, 0.44);
  --panel-strong: rgba(255, 255, 255, 0.68);
  --shadow: 0 22px 70px rgba(17, 17, 17, 0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 20% 0%, rgba(255, 255, 255, 0.72), transparent 30%),
    linear-gradient(180deg, #f7f2ea 0%, #efe7dc 48%, #f7f2ea 100%);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 28px 0 56px;
}

.top-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 0 28px;
  font-size: 13px;
  color: rgba(17, 17, 17, 0.68);
}

.brand {
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
}

.nav-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-actions a,
.book-action,
.cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.32);
  text-decoration: none;
  font-size: 13px;
  font-weight: 650;
  color: rgba(17, 17, 17, 0.86);
}

.nav-actions a.primary,
.book-action.primary {
  background: #111111;
  color: #ffffff;
}

.hero-banner {
  display: grid;
  grid-template-columns: minmax(260px, 0.78fr) minmax(0, 1.22fr);
  gap: 34px;
  align-items: center;
  min-height: 540px;
  padding: clamp(24px, 5vw, 54px);
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
  text-align: left;
}

.book-cover-panel {
  align-self: stretch;
  min-height: 420px;
}

.book-cover-panel img {
  width: 100%;
  height: 100%;
  min-height: 420px;
  display: block;
  object-fit: cover;
  border-radius: 20px;
  border: 1px solid rgba(17, 17, 17, 0.08);
  box-shadow: 0 18px 55px rgba(17, 17, 17, 0.16);
}

.hero-copy {
  max-width: 700px;
}

.hero-banner h1 {
  margin: 0 0 14px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(42px, 7vw, 82px);
  line-height: 0.94;
  letter-spacing: 0;
  font-weight: 500;
}

.subtitle {
  max-width: 680px;
  margin: 0 0 18px;
  color: rgba(17, 17, 17, 0.72);
  font-size: clamp(19px, 2.5vw, 30px);
  line-height: 1.18;
}

.author {
  display: inline-flex;
  margin: 0 0 22px;
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: rgba(17, 17, 17, 0.62);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.book-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.section {
  margin-top: 18px;
  padding: clamp(24px, 4vw, 42px);
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--panel);
  box-shadow: 0 16px 45px rgba(17, 17, 17, 0.05);
}

.section-title {
  margin: 0 0 18px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(27px, 4vw, 44px);
  line-height: 1.05;
  letter-spacing: 0;
  font-weight: 500;
}

.section p {
  color: rgba(17, 17, 17, 0.70) !important;
  font-size: 16px;
}

.pain-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 18px;
}

.pain-item,
.chapter-box,
.math-callout,
.quote-block {
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel-strong);
  padding: 18px;
}

.pain-item h3,
.chapter-box h3 {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.22;
}

.pain-item p,
.chapter-box p {
  margin: 0;
}

.math-expr {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 22px;
  color: rgba(17, 17, 17, 0.86);
  overflow-wrap: anywhere;
}

.math-desc {
  margin-top: 8px;
  color: var(--muted);
}

.compare-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel-strong);
}

.compare-table th,
.compare-table td {
  padding: 18px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

.compare-table th {
  background: rgba(17, 17, 17, 0.08);
  font-size: 14px;
}

.compare-table tr:last-child td {
  border-bottom: 0;
}

.compare-table td + td,
.compare-table th + th {
  border-left: 1px solid var(--line);
}

.chapter-box + .chapter-box {
  margin-top: 12px;
}

.chapter-badge {
  display: inline-flex;
  margin-bottom: 10px;
  padding: 5px 9px;
  border-radius: 999px;
  background: rgba(17, 17, 17, 0.08);
  color: rgba(17, 17, 17, 0.62);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.action-list {
  margin: 18px 0 0;
  padding-left: 20px;
  color: rgba(17, 17, 17, 0.72);
}

.action-list li {
  margin-bottom: 12px;
}

.quote-block {
  margin-top: 22px;
}

.quote-block p {
  margin: 0 0 8px;
  color: rgba(17, 17, 17, 0.88) !important;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 22px;
  line-height: 1.3;
}

.quote-block span {
  color: rgba(17, 17, 17, 0.56);
}

.cta-section {
  margin-top: 18px;
  padding: clamp(24px, 4vw, 42px);
  border: 1px solid rgba(17, 17, 17, 0.10);
  border-radius: 24px;
  background: #111111;
  color: #ffffff;
  box-shadow: var(--shadow);
}

.cta-section h2 {
  margin: 0 0 10px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(30px, 5vw, 54px);
  line-height: 1;
  font-weight: 500;
}

.cta-section p {
  max-width: 660px;
  margin: 0 0 18px;
  color: rgba(255, 255, 255, 0.72);
}

.kit-embed {
  max-width: 760px;
}

.kit-embed form {
  margin: 0;
}

.kit-embed .formkit-fields {
  display: flex;
  gap: 10px;
  align-items: stretch;
}

.kit-embed .formkit-field {
  flex: 1;
}

.kit-embed input {
  width: 100%;
  min-height: 46px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 10px;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.10);
  color: #ffffff;
  font: inherit;
}

.kit-embed input::placeholder {
  color: rgba(255, 255, 255, 0.62);
}

.kit-embed button {
  min-height: 46px;
  border: 0;
  border-radius: 10px;
  padding: 12px 18px;
  background: #ffffff;
  color: #111111;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.footer-note {
  margin-top: 18px;
  color: rgba(255, 255, 255, 0.48);
  font-size: 12px;
}

@media (max-width: 840px) {
  .container {
    width: min(100% - 24px, 1120px);
  }

  .top-nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero-banner,
  .pain-grid {
    grid-template-columns: 1fr;
  }

  .book-cover-panel,
  .book-cover-panel img {
    min-height: 0;
  }

  .compare-table {
    display: block;
    overflow-x: auto;
  }

  .kit-embed .formkit-fields {
    flex-direction: column;
  }
}