/* ============================================
   THE HUMAN STACK — Sci-Fi / Intelligence Age Theme
   ============================================ */

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

/* ---- Variables ---- */
:root {
  --bg-void:    #020912;
  --bg-deep:    #060d1f;
  --bg-card:    #0c1932;
  --bg-glass:   rgba(12, 25, 50, 0.85);

  --cyan:       #00d4ff;
  --cyan-dim:   rgba(0, 212, 255, 0.08);
  --cyan-mid:   rgba(0, 212, 255, 0.22);
  --cyan-glow:  rgba(0, 212, 255, 0.38);

  /* Per-book accent (overridden per page) */
  --bk:         #00d4ff;
  --bk-dim:     rgba(0, 212, 255, 0.08);
  --bk-mid:     rgba(0, 212, 255, 0.22);

  /* Book palette */
  --b1:         #00d4ff;
  --b1-dim:     rgba(0, 212, 255, 0.08);
  --b1-mid:     rgba(0, 212, 255, 0.22);

  --b2:         #ff4d6d;
  --b2-dim:     rgba(255, 77, 109, 0.08);
  --b2-mid:     rgba(255, 77, 109, 0.22);

  --b3:         #fbbf24;
  --b3-dim:     rgba(251, 191, 36, 0.08);
  --b3-mid:     rgba(251, 191, 36, 0.22);

  --text:       #dde6f5;
  --text-muted: #8896b0;
  --text-dim:   #475569;

  --border:     rgba(255, 255, 255, 0.06);

  --radius:     10px;
  --radius-lg:  18px;
  --radius-xl:  26px;

  --font-display: 'Orbitron', monospace;
  --font-ui:      'Space Grotesk', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-ui);
  background: var(--bg-void);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

/* ---- Starfield Canvas ---- */
#starfield {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

/* ---- Site Wrapper (above canvas) ---- */
.site-wrap { position: relative; z-index: 1; }

/* ---- Container ---- */
.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============================================
   NAVIGATION
   ============================================ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(2, 9, 18, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

.nav-brand {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--cyan);
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-logo {
  width: 30px;
  height: 30px;
  border: 2px solid var(--cyan);
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 900;
  box-shadow: 0 0 14px var(--cyan-glow);
  flex-shrink: 0;
  color: var(--cyan);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-transform: uppercase;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

.nav-cta {
  color: var(--bg-void) !important;
  background: var(--cyan) !important;
  padding: 8px 18px !important;
  border-radius: 6px !important;
  font-family: var(--font-display) !important;
  font-size: 10px !important;
  font-weight: 700 !important;
  letter-spacing: 0.12em !important;
  transition: box-shadow 0.25s, transform 0.25s !important;
}
.nav-cta:hover {
  box-shadow: 0 0 22px var(--cyan-glow) !important;
  transform: translateY(-1px);
}

/* ============================================
   HERO
   ============================================ */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 80px 24px;
  overflow: hidden;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right,  rgba(0,212,255,0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0,212,255,0.04) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black, transparent);
  animation: grid-drift 28s linear infinite;
}
@keyframes grid-drift {
  0%   { background-position: 0 0; }
  100% { background-position: 80px 80px; }
}

.hero-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 700px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(0,212,255,0.07) 0%, transparent 68%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 880px;
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: 28px;
  display: inline-flex;
  align-items: center;
  gap: 14px;
}
.hero-eyebrow::before,
.hero-eyebrow::after {
  content: '';
  display: block;
  width: 36px;
  height: 1px;
  background: var(--cyan);
  opacity: 0.55;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(36px, 7.5vw, 82px);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin-bottom: 30px;
}

.hero-title .gradient-text {
  display: block;
  background: linear-gradient(130deg, var(--cyan) 0%, #7c3aed 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: glitch-flicker 7s infinite;
}

@keyframes glitch-flicker {
  0%, 86%, 100% { filter: none; transform: translate(0); }
  88% {
    filter: drop-shadow(0 0 10px rgba(0,212,255,0.9)) drop-shadow(2px 0 0 rgba(255,0,100,0.6));
    transform: translate(-2px, 0);
  }
  90% {
    filter: drop-shadow(0 0 8px rgba(124,58,237,0.9)) drop-shadow(-2px 0 0 rgba(0,212,255,0.6));
    transform: translate(2px, 0);
  }
  92% { filter: none; transform: translate(0); }
}

.hero-subtitle {
  font-size: clamp(15px, 2.2vw, 19px);
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 48px;
  line-height: 1.72;
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
}

.btn-primary   { background: var(--cyan); color: var(--bg-void); }
.btn-primary:hover {
  box-shadow: 0 0 30px var(--cyan-glow), 0 8px 24px rgba(0,0,0,0.5);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-outline:hover {
  border-color: rgba(255,255,255,0.28);
  background: rgba(255,255,255,0.04);
  transform: translateY(-2px);
}

.btn-b1 { background: var(--b1); color: var(--bg-void); }
.btn-b1:hover { box-shadow: 0 0 30px var(--b1-mid), 0 8px 24px rgba(0,0,0,0.5); transform: translateY(-2px); }

.btn-b2 { background: var(--b2); color: #fff; }
.btn-b2:hover { box-shadow: 0 0 30px var(--b2-mid), 0 8px 24px rgba(0,0,0,0.5); transform: translateY(-2px); }

.btn-b3 { background: var(--b3); color: var(--bg-void); }
.btn-b3:hover { box-shadow: 0 0 30px var(--b3-mid), 0 8px 24px rgba(0,0,0,0.5); transform: translateY(-2px); }

/* ============================================
   MARQUEE
   ============================================ */
.marquee-wrap {
  overflow: hidden;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 13px 0;
  background: var(--bg-deep);
}
.marquee-track {
  display: flex;
  gap: 0;
  animation: marquee 30s linear infinite;
  width: max-content;
}
.marquee-item {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--text-dim);
  text-transform: uppercase;
  white-space: nowrap;
  padding: 0 40px;
  display: flex;
  align-items: center;
  gap: 20px;
}
.marquee-item em { color: var(--cyan); font-style: normal; }
@keyframes marquee {
  0%   { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ============================================
   BOOKS SECTION
   ============================================ */
.books-section {
  padding: 88px 24px 120px;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}
.section-label::before, .section-label::after {
  content: '';
  display: block;
  width: 36px;
  height: 1px;
  background: currentColor;
  opacity: 0.4;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(26px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  line-height: 1.15;
}

.section-desc {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.72;
}

/* Books grid */
.books-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  max-width: 1180px;
  margin: 0 auto;
}

/* --- Book Card --- */
.book-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.book-card[data-book="1"] { --bk: var(--b1); --bk-dim: var(--b1-dim); --bk-mid: var(--b1-mid); }
.book-card[data-book="2"] { --bk: var(--b2); --bk-dim: var(--b2-dim); --bk-mid: var(--b2-mid); }
.book-card[data-book="3"] { --bk: var(--b3); --bk-dim: var(--b3-dim); --bk-mid: var(--b3-mid); }

.book-card:hover {
  transform: translateY(-8px);
  border-color: var(--bk);
  box-shadow: 0 0 40px var(--bk-mid), 0 28px 60px rgba(0,0,0,0.6);
}

/* Scan-line sweep on hover */
.book-card::before {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  top: -4px;
  background: linear-gradient(to right, transparent, var(--bk), transparent);
  opacity: 0;
  z-index: 10;
  transition: opacity 0.3s;
}
.book-card:hover::before {
  opacity: 0.7;
  animation: scan-line 0.9s ease forwards;
}
@keyframes scan-line {
  0%   { top: -4px; }
  100% { top: 105%; }
}

/* --- Book Cover (CSS art) --- */
.book-cover {
  aspect-ratio: 5 / 7;
  position: relative;
  overflow: hidden;
}
.book-cover[data-book="1"] {
  background: linear-gradient(155deg, #010d1e 0%, #001827 55%, #010e20 100%);
}
.book-cover[data-book="2"] {
  background: linear-gradient(155deg, #100208 0%, #1c0310 55%, #0b0108 100%);
}
.book-cover[data-book="3"] {
  background: linear-gradient(155deg, #100f02 0%, #1a1800 55%, #0d0c01 100%);
}

.cover-art {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.cover-band {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 22px 18px 18px;
  background: linear-gradient(to top, rgba(0,0,0,0.96) 0%, transparent 100%);
  z-index: 3;
}
.cover-title-sm {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--bk);
  margin-bottom: 3px;
  line-height: 1.25;
}
.cover-sub-sm {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.06em;
  color: rgba(255,255,255,0.44);
  line-height: 1.4;
}
.cover-brand-sm {
  position: absolute;
  top: 14px;
  right: 14px;
  font-family: var(--font-mono);
  font-size: 8px;
  letter-spacing: 0.18em;
  color: var(--bk);
  opacity: 0.65;
  text-transform: uppercase;
  z-index: 3;
}

/* --- Book Card Body --- */
.book-card-body {
  padding: 26px 26px 30px;
  display: flex;
  flex-direction: column;
  flex: 1;
}
.book-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--bk);
  background: var(--bk-dim);
  border: 1px solid var(--bk-mid);
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 14px;
}
.book-card-title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.01em;
  line-height: 1.3;
  margin-bottom: 5px;
  color: var(--text);
}
.book-card-sub {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 14px;
}
.book-card-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.72;
  flex: 1;
  margin-bottom: 22px;
}
.book-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.book-price {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  color: var(--bk);
  line-height: 1;
}
.book-price small {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-dim);
  font-weight: 400;
  margin-left: 2px;
}
.book-read-more {
  font-family: var(--font-display);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--bk);
  transition: letter-spacing 0.2s;
}
.book-read-more:hover { letter-spacing: 0.16em; }

/* ============================================
   STATS BAR
   ============================================ */
.stats-bar {
  padding: 52px 24px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-deep);
}
.stats-inner {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  justify-content: space-around;
  gap: 24px;
  flex-wrap: wrap;
}
.stat { text-align: center; }
.stat-num {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 46px);
  font-weight: 900;
  color: var(--cyan);
  line-height: 1;
  margin-bottom: 8px;
}
.stat-lbl {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.07em;
  max-width: 140px;
}

/* ============================================
   BRAND / ABOUT STRIP
   ============================================ */
.brand-section {
  padding: 88px 24px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(to bottom, transparent, rgba(0,212,255,0.018), transparent);
}
.brand-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}
.brand-text .section-label { justify-content: flex-start; }
.brand-text .section-label::before { display: none; }
.brand-text .section-label::after { flex: 0; }
.brand-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 20px;
}

/* Terminal quote */
.t-quote {
  background: var(--bg-deep);
  border: 1px solid var(--border);
  border-left: 3px solid var(--cyan);
  border-radius: var(--radius);
  padding: 22px 24px;
  margin-bottom: 16px;
  position: relative;
}
.t-quote::before {
  content: '>';
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
  position: absolute;
  top: 22px;
  left: 24px;
}
.t-quote-text {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text);
  line-height: 1.65;
  padding-left: 22px;
  font-style: italic;
}
.t-quote-src {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-dim);
  padding-left: 22px;
  margin-top: 10px;
  letter-spacing: 0.08em;
}
.t-quote-src::before { content: '// '; }

/* ============================================
   BOOK PAGE — HERO
   ============================================ */
.book-hero {
  position: relative;
  padding: 80px 24px 90px;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}
.book-hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right,  rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black, transparent);
}
.book-hero-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 500px;
  pointer-events: none;
}
.book-hero-inner {
  position: relative;
  z-index: 2;
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 60px;
  align-items: center;
}
.book-cover-lg {
  aspect-ratio: 5 / 7;
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  box-shadow: 0 0 60px var(--bk-mid), 0 32px 80px rgba(0,0,0,0.75);
}
.book-hero-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--bk);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.book-hero-tag::before { content: ''; width: 20px; height: 1px; background: currentColor; }

.book-hero-title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4.5vw, 52px);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 12px;
  color: var(--bk);
}
.book-hero-subtitle {
  font-size: clamp(15px, 2vw, 19px);
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.5;
}
.book-hero-byline {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 28px;
}
.book-hero-desc {
  font-size: 15px;
  color: var(--text);
  line-height: 1.78;
  margin-bottom: 36px;
  max-width: 560px;
}
.book-hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ============================================
   BOOK PAGE — LEARN GRID
   ============================================ */
.book-content { padding: 80px 24px; }
.book-content-inner { max-width: 1180px; margin: 0 auto; }

.learn-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 18px;
  margin-top: 44px;
}
.learn-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.learn-item:hover {
  border-color: var(--bk);
  box-shadow: 0 0 20px var(--bk-dim);
}
.learn-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--bk);
  margin-bottom: 10px;
  letter-spacing: 0.12em;
}
.learn-title {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
  line-height: 1.3;
}
.learn-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ============================================
   BOOK PAGE — CHAPTERS
   ============================================ */
.chapters { margin-top: 44px; }
.chapter-item {
  display: flex;
  gap: 20px;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
  align-items: flex-start;
}
.chapter-num {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--bk);
  min-width: 38px;
  margin-top: 3px;
  letter-spacing: 0.1em;
}
.chapter-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}
.chapter-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ============================================
   BUY SECTION
   ============================================ */
.buy-section {
  padding: 80px 24px;
  background: var(--bg-deep);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.buy-inner {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
}
.buy-price {
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 900;
  color: var(--bk);
  line-height: 1;
  margin-bottom: 6px;
}
.buy-price-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 28px;
}
.buy-formats {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 32px;
}
.buy-format {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--text-muted);
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: 4px;
  text-transform: uppercase;
}

/* ============================================
   RELATED BOOKS
   ============================================ */
.related-section {
  padding: 72px 24px;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 40px;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}
.related-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.related-card:hover {
  border-color: var(--rel-color, var(--cyan));
  box-shadow: 0 0 24px rgba(0,0,0,0.4);
  transform: translateY(-4px);
}
.related-card-tag {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--rel-color, var(--cyan));
}
.related-card-title {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}
.related-card-sub {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.5;
  flex: 1;
}
.related-card-link {
  font-family: var(--font-display);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--rel-color, var(--cyan));
  align-self: flex-start;
  transition: letter-spacing 0.2s;
}
.related-card-link:hover { letter-spacing: 0.16em; }

/* ============================================
   ABOUT PAGE
   ============================================ */
.about-hero {
  padding: 90px 24px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}
.about-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right,  rgba(0,212,255,0.035) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0,212,255,0.035) 1px, transparent 1px);
  background-size: 70px 70px;
  mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black, transparent);
}
.about-content {
  position: relative;
  z-index: 2;
  max-width: 760px;
  margin: 0 auto;
}
.about-body {
  padding: 72px 24px;
}
.about-body-inner {
  max-width: 760px;
  margin: 0 auto;
}
.about-p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.82;
  margin-bottom: 20px;
}
.about-highlight {
  background: var(--bg-deep);
  border: 1px solid var(--border);
  border-left: 3px solid var(--cyan);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin: 36px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text);
  line-height: 1.7;
  font-style: italic;
}

/* ============================================
   FOOTER
   ============================================ */
footer {
  padding: 44px 24px 28px;
  border-top: 1px solid var(--border);
}
.footer-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-brand {
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.14em;
}
.footer-links {
  display: flex;
  gap: 26px;
  list-style: none;
}
.footer-links a {
  font-size: 12px;
  color: var(--text-dim);
  transition: color 0.2s;
}
.footer-links a:hover { color: var(--text-muted); }
.footer-copy {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-dim);
  letter-spacing: 0.07em;
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fade-up {
  from { opacity: 0; transform: translateY(22px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fu  { opacity: 0; animation: fade-up 0.7s ease forwards; }
.fu1 { animation-delay: 0.08s; }
.fu2 { animation-delay: 0.22s; }
.fu3 { animation-delay: 0.38s; }
.fu4 { animation-delay: 0.54s; }

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 960px) {
  .books-grid { grid-template-columns: 1fr; max-width: 460px; margin: 0 auto; }
  .brand-inner { grid-template-columns: 1fr; gap: 44px; }
  .book-hero-inner { grid-template-columns: 1fr; }
  .book-cover-lg { max-width: 260px; margin: 0 auto; }
  .related-grid { grid-template-columns: 1fr; max-width: 460px; }
}
@media (max-width: 680px) {
  .nav-links { display: none; }
  .hero { min-height: 80vh; }
  .stats-inner { gap: 32px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}