@import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;600;700;900&family=Inter:wght@300;400;500;600;700&family=Space+Grotesk:wght@400;500;600;700&display=swap');

:root {
  --bg-primary: #f0f6ff;
  --bg-secondary: #e4eef9;
  --bg-card: #ffffff;
  --bg-card-hover: #f5faff;
  --accent-cyan: #0077cc;
  --accent-cyan-dim: #005fa3;
  --accent-green: #00a86b;
  --accent-orange: #e05c00;
  --text-primary: #0a1f35;
  --text-secondary: #2a5278;
  --text-muted: #6a92b0;
  --border: #c2d9ef;
  --border-bright: #0077cc44;
  --glow-cyan: 0 4px 24px #0077cc22;
  --glow-strong: 0 4px 40px #0077cc44;
  --nav-bg: rgba(240,246,255,0.95);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,119,204,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,119,204,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: 0;
}

/* NAV */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 2px 16px rgba(0,119,204,0.08);
}

.nav-logo {
  font-family: 'Orbitron', monospace;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-decoration: none;
  letter-spacing: 0.04em;
  line-height: 1.2;
}
.nav-logo span { color: var(--text-primary); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 600;
  font-size: 0.88rem;
  color: var(--text-secondary);
  text-decoration: none;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--accent-cyan); }

.nav-cta {
  background: var(--accent-cyan) !important;
  color: #fff !important;
  padding: 0.5rem 1.2rem;
  border-radius: 6px;
  font-weight: 700 !important;
  transition: all 0.2s !important;
}
.nav-cta:hover {
  background: var(--accent-cyan-dim) !important;
  box-shadow: var(--glow-cyan);
}

/* BUTTONS */
.btn-primary {
  display: inline-block;
  background: var(--accent-cyan);
  color: #fff;
  padding: 0.9rem 2.2rem;
  border-radius: 6px;
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.05em;
  text-decoration: none;
  text-transform: uppercase;
  transition: all 0.25s;
  border: 2px solid var(--accent-cyan);
  cursor: pointer;
}
.btn-primary:hover {
  background: var(--accent-cyan-dim);
  box-shadow: var(--glow-strong);
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-block;
  background: transparent;
  color: var(--accent-cyan);
  padding: 0.9rem 2.2rem;
  border-radius: 6px;
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.05em;
  text-decoration: none;
  text-transform: uppercase;
  transition: all 0.25s;
  border: 2px solid var(--accent-cyan);
  cursor: pointer;
}
.btn-secondary:hover {
  background: var(--accent-cyan);
  color: #fff;
}

.section-label {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.75rem;
  color: var(--accent-cyan);
  letter-spacing: 0.3em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
  font-weight: 600;
}

/* FOOTER */
footer {
  background: #0a1f35;
  border-top: 1px solid #1a3a55;
  padding: 3.5rem 2rem 1.5rem;
  position: relative;
  z-index: 1;
}

.footer-inner { max-width: 1100px; margin: 0 auto; }

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}

.footer-brand .nav-logo { color: #00aaff; font-size: 0.85rem; }
.footer-brand p { margin-top: 1rem; font-size: 0.88rem; color: #6a92b0; line-height: 1.7; }

.footer-col h4 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.7rem;
  color: #00aaff;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  font-weight: 700;
}

.footer-col a {
  display: block;
  color: #6a92b0;
  text-decoration: none;
  font-size: 0.88rem;
  margin-bottom: 0.5rem;
  transition: color 0.2s;
}
.footer-col a:hover { color: #00aaff; }
.footer-col p { color: #6a92b0; font-size: 0.88rem; margin-bottom: 0.4rem; }

.footer-bottom {
  border-top: 1px solid #1a3a55;
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-bottom p { font-size: 0.8rem; color: #3a6a85; }

/* CARD */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  transition: all 0.3s;
  box-shadow: 0 2px 12px rgba(0,119,204,0.06);
}
.card:hover {
  border-color: var(--accent-cyan);
  box-shadow: var(--glow-strong);
  transform: translateY(-4px);
}

section { position: relative; z-index: 1; }
main { padding-top: 70px; }

/* HAMBURGER */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--accent-cyan);
  transition: all 0.3s;
}

@media (max-width: 768px) {
  html, body { overflow-x: hidden; width: 100%; }

  /* NAV */
  nav { padding: 0 1rem; height: 64px; }
  main { padding-top: 64px; }
  .nav-logo { font-size: 0.78rem; }
  .nav-hamburger { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: var(--nav-bg);
    flex-direction: column;
    padding: 1.2rem 1.5rem;
    gap: 1rem;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
    z-index: 999;
  }
  .nav-links.open { display: flex; }

  /* BUTTONS */
  .btn-primary, .btn-secondary {
    padding: 0.8rem 1.4rem;
    font-size: 0.88rem;
    width: 100%;
    text-align: center;
    display: block;
  }

  /* SECTIONS */
  section,
  div[style*="padding:5rem 2rem"],
  div[style*="padding: 5rem 2rem"] { padding: 2.5rem 1.2rem !important; }

  /* HERO */
  .hero, .page-hero { padding: 2.5rem 1.2rem 2rem !important; }
  .hero-inner, .page-hero-inner {
    grid-template-columns: 1fr !important;
    gap: 1.5rem;
    text-align: center;
  }
  .hero h1, .hero-content h1 {
    font-size: clamp(1.6rem, 6.5vw, 2.2rem) !important;
    line-height: 1.2;
  }
  .hero p { font-size: 0.95rem !important; max-width: 100% !important; }
  .hero-btns, .hero-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
    max-width: 100% !important;
  }
  .hero-btns a, .hero-actions a { width: 100% !important; text-align: center !important; }

  /* BOOK COVERS */
  .hero-book-img { width: 160px !important; height: auto !important; margin: 0 auto; }

  /* PRICE */
  .price-main { font-size: 2rem !important; }

  /* GRIDS */
  .products-grid,
  div[style*="grid-template-columns: repeat(auto-fit"] { grid-template-columns: 1fr !important; gap: 1.2rem; }

  /* PRODUCT CARDS */
  .product-img-wrap { padding: 1.2rem; }
  .product-img-wrap img { width: 140px !important; height: auto !important; }
  .product-body { padding: 1.2rem; }
  .product-body h3 { font-size: 1.1rem; }
  .product-price { font-size: 1.6rem; }
  .product-features li { font-size: 0.85rem; }

  /* BUTTON GROUPS */
  div[style*="display:flex;flex-direction:column;gap:0.7rem"] a,
  .product-actions a {
    width: 100% !important; text-align: center !important;
    font-size: 0.85rem !important; padding: 0.75rem 1rem !important;
  }

  /* PAYMENT ICONS */
  .payment-icons img { height: 22px; }
  .card-icons img { height: 30px; }

  /* SPECS BAR */
  .specs-bar { padding: 1rem; }
  .specs-bar-inner { justify-content: center; flex-wrap: wrap; gap: 0.8rem 1.5rem; }
  .spec-val { font-size: 0.82rem; }
  .spec-label { font-size: 0.6rem; }

  /* DETAIL PAGES */
  .detail-section { padding: 2.5rem 1.2rem !important; }
  .detail-inner { grid-template-columns: 1fr !important; gap: 2rem; }
  .sidebar-cta { position: static !important; }
  .sidebar-actions a { width: 100%; text-align: center; display: block; }
  .sample-section { padding: 2.5rem 1.2rem !important; }
  .sample-body { padding: 1.5rem 1rem; }
  .upsell-banner a { display: block; width: 100%; text-align: center; }

  /* CHECKOUT */
  .checkout-page { padding: 2rem 1rem !important; }
  .checkout-grid { grid-template-columns: 1fr !important; }
  .order-summary { position: static !important; }
  .form-row { grid-template-columns: 1fr !important; }
  .form-group input, .form-group select, .form-group textarea { font-size: 16px !important; }
  .submit-btn { font-size: 0.9rem; padding: 1rem; }

  /* CTA STRIP */
  .cta-strip { padding: 3rem 1.2rem !important; }
  .cta-strip h2 { font-size: clamp(1.4rem, 5.5vw, 1.8rem) !important; }
  .cta-btns { flex-direction: column; align-items: stretch; gap: 0.75rem; }
  .cta-btns a { width: 100%; text-align: center; }

  /* CONTACT */
  div[style*="max-width:700px"], div[style*="max-width:800px"],
  div[style*="max-width:900px"], div[style*="max-width:1100px"] {
    padding-left: 0 !important; padding-right: 0 !important;
  }
  div[style*="padding:2.5rem"] { padding: 1.5rem !important; }

  /* FOOTER */
  footer { padding: 2.5rem 1.2rem 1.5rem; }
  .footer-grid { grid-template-columns: 1fr !important; gap: 1.5rem; }
  .footer-bottom { flex-direction: column; text-align: center; gap: 0.4rem; }
  .footer-contact-block a { word-break: break-all; }
}

/* Small phones */
@media (max-width: 400px) {
  nav { padding: 0 0.8rem; }
  .nav-logo { font-size: 0.72rem; }
  section,
  div[style*="padding:5rem 2rem"] { padding: 2rem 1rem !important; }
  .hero-book-img { width: 130px !important; }
  .product-img-wrap img { width: 120px !important; }
  .checkout-page { padding: 1.5rem 0.8rem !important; }
}