/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --blue-light: #eff6ff;
  --gold: #d4a853;
  --gold-light: #faf5eb;
  --text: #1a1a2e;
  --text-muted: #555;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 4px 12px rgba(0,0,0,.05);
  --shadow-lg: 0 4px 12px rgba(0,0,0,.1), 0 12px 32px rgba(0,0,0,.08);
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid transparent;
  border-radius: 8px;
  padding: 12px 28px;
  cursor: pointer;
  transition: all .2s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--blue);
  color: #fff;
  border-color: var(--blue);
}
.btn-primary:hover {
  background: var(--blue-dark);
  border-color: var(--blue-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(37,99,235,.35);
}

.btn-outline {
  background: transparent;
  color: var(--blue);
  border-color: var(--blue);
}
.btn-outline:hover {
  background: var(--blue);
  color: #fff;
  transform: translateY(-1px);
}

.btn-lg { font-size: 1.05rem; padding: 14px 32px; }
.btn-sm { font-size: .875rem; padding: 8px 20px; }

/* ===== Nav ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,.06);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
}
.nav-icon { flex-shrink: 0; }
.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: .925rem;
  font-weight: 500;
}
.nav-links a:not(.btn):hover { color: var(--blue); }

@media (max-width: 600px) {
  .nav-links a:not(.btn) { display: none; }
}

/* ===== Hero ===== */
.hero {
  padding: 120px 0 80px;
  background: linear-gradient(170deg, var(--bg) 60%, var(--blue-light) 100%);
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.hero-eyebrow {
  font-size: .9rem;
  font-weight: 600;
  color: var(--blue);
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: 12px;
}
.hero-title {
  font-family: var(--font-display);
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  color: var(--text);
  margin-bottom: 12px;
}
.hero-subtitle {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.hero-tagline {
  font-size: 1.05rem;
  color: var(--gold);
  font-weight: 600;
  margin-bottom: 32px;
}
.hero-ctas {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

@media (max-width: 768px) {
  .hero { padding: 100px 0 60px; }
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-title { font-size: 2.5rem; }
  .hero-ctas { justify-content: center; }
  .hero-book { order: -1; }
}

/* ===== 3D Book ===== */
.hero-book {
  display: flex;
  justify-content: center;
}
.book-3d {
  perspective: 800px;
  width: 240px;
  height: 340px;
}
.book-cover {
  width: 240px;
  height: 340px;
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  border-radius: 4px 12px 12px 4px;
  box-shadow:
    -6px 6px 18px rgba(0,0,0,.25),
    inset 0 0 0 1px rgba(255,255,255,.08);
  transform: rotateY(-18deg);
  transform-style: preserve-3d;
  transition: transform .4s ease;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: bookFloat 4s ease-in-out infinite;
}
.book-cover:hover {
  transform: rotateY(-8deg);
}
.book-cover::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(to right, rgba(0,0,0,.3), transparent);
  border-radius: 4px 0 0 4px;
}
.book-cover-content {
  padding: 32px 24px;
  text-align: center;
  color: #fff;
}
.book-cover-top {
  margin-bottom: 16px;
}
.book-title {
  font-family: var(--font-display);
  font-size: 1.65rem;
  font-weight: 800;
  line-height: 1.2;
  color: #fff;
  margin-bottom: 12px;
}
.book-divider {
  width: 48px;
  height: 2px;
  background: var(--gold);
  margin: 0 auto 12px;
}
.book-sub {
  font-size: .78rem;
  color: rgba(255,255,255,.75);
  line-height: 1.4;
  margin-bottom: 20px;
}
.book-authors {
  font-size: .72rem;
  font-weight: 600;
  color: var(--gold);
  text-transform: uppercase;
  letter-spacing: .1em;
}

@keyframes bookFloat {
  0%, 100% { transform: rotateY(-18deg) translateY(0); }
  50% { transform: rotateY(-18deg) translateY(-8px); }
}

/* ===== Section Titles ===== */
.section-title {
  font-family: var(--font-display);
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.section-desc {
  color: var(--text-muted);
  font-size: 1.1rem;
  margin-bottom: 48px;
}

/* ===== What You'll Learn ===== */
.learn {
  padding: 100px 0;
  background: var(--bg);
  text-align: center;
}
.learn-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  text-align: left;
}
.learn-card {
  background: var(--bg-alt);
  border: 1px solid rgba(0,0,0,.06);
  border-radius: var(--radius);
  padding: 28px;
  transition: all .2s ease;
}
.learn-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}
.learn-icon {
  width: 52px;
  height: 52px;
  border-radius: 10px;
  background: var(--blue-light);
  color: var(--blue);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}
.learn-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.learn-card p {
  font-size: .92rem;
  color: var(--text-muted);
  line-height: 1.55;
}

@media (max-width: 900px) {
  .learn-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .learn-grid { grid-template-columns: 1fr; }
  .section-title { font-size: 1.85rem; }
}

/* ===== Authors ===== */
.authors {
  padding: 100px 0;
  background: var(--bg-alt);
}
.authors-inner {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 60px;
  align-items: start;
}
.authors-text p {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.7;
}
.authors-text strong { color: var(--text); }
.authors-visual {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.authors-card {
  background: var(--bg);
  border: 1px solid rgba(0,0,0,.06);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  box-shadow: var(--shadow);
}
.authors-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-top: 12px;
  margin-bottom: 4px;
}
.authors-card p {
  font-size: .88rem;
  color: var(--text-muted);
}

@media (max-width: 768px) {
  .authors-inner { grid-template-columns: 1fr; }
}

/* ===== Buy Now ===== */
.buy {
  padding: 100px 0;
  background: var(--bg);
  text-align: center;
}
.buy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.buy-card {
  background: var(--bg-alt);
  border: 1px solid rgba(0,0,0,.06);
  border-radius: var(--radius);
  padding: 40px 28px;
  text-align: center;
  transition: all .2s ease;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.buy-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--blue);
}
.buy-card-featured {
  border-color: var(--blue);
  box-shadow: var(--shadow);
}
.buy-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gold);
  color: #fff;
  font-size: .75rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: .05em;
}
.buy-icon {
  color: var(--blue);
  margin-bottom: 8px;
}
.buy-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
}
.buy-format {
  font-size: .9rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

@media (max-width: 600px) {
  .buy-grid { grid-template-columns: 1fr; max-width: 360px; margin: 0 auto; }
}

/* ===== Social Proof ===== */
.proof {
  padding: 80px 0;
  background: linear-gradient(170deg, var(--blue-light) 0%, var(--gold-light) 100%);
  text-align: center;
}
.proof-inner {
  max-width: 680px;
  margin: 0 auto;
}
.proof h2 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  margin: 20px 0 16px;
  line-height: 1.35;
}
.proof p {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  line-height: 1.65;
}

/* ===== Email Capture ===== */
.capture {
  padding: 100px 0;
  background: var(--text);
  color: #fff;
}
.capture-inner {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}
.capture h2 {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.capture-text p {
  color: rgba(255,255,255,.7);
  font-size: 1.05rem;
  margin-bottom: 32px;
}
.capture-input-wrap {
  display: flex;
  gap: 12px;
}
.capture-input {
  flex: 1;
  padding: 14px 18px;
  border: 2px solid rgba(255,255,255,.15);
  border-radius: 8px;
  background: rgba(255,255,255,.08);
  color: #fff;
  font-size: 1rem;
  font-family: var(--font-body);
  outline: none;
  transition: border-color .2s;
}
.capture-input::placeholder { color: rgba(255,255,255,.4); }
.capture-input:focus { border-color: var(--blue); }
.capture-btn { flex-shrink: 0; }
.capture-note {
  font-size: .82rem;
  color: rgba(255,255,255,.45);
  margin-top: 12px;
}
.capture-success {
  color: var(--gold);
  font-weight: 600;
  font-size: .95rem;
  margin-top: 16px;
}

@media (max-width: 500px) {
  .capture-input-wrap { flex-direction: column; }
}

/* ===== Footer ===== */
.footer {
  padding: 40px 0;
  background: var(--bg-alt);
  border-top: 1px solid rgba(0,0,0,.06);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}
.footer-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 4px;
}
.footer-left p {
  font-size: .82rem;
  color: var(--text-muted);
}
.footer-right {
  display: flex;
  gap: 24px;
  font-size: .9rem;
}
.footer-right a:hover { color: var(--blue); }

@media (max-width: 500px) {
  .footer-inner { flex-direction: column; text-align: center; }
  .footer-right { flex-direction: column; gap: 8px; }
}