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

:root {
  --orange:      #f97316;
  --orange-dark: #ea6a0a;
  --orange-light:#fff7ed;
  --dark-navy:   #0f172a;
  --deep-purple: #1e1b4b;
  --mid-dark:    #1a2744;
  --white:       #ffffff;
  --off-white:   #f8fafc;
  --gray-100:    #f1f5f9;
  --gray-200:    #e2e8f0;
  --gray-400:    #94a3b8;
  --gray-600:    #475569;
  --gray-800:    #1e293b;
  --text-dark:   #0f172a;
  --text-muted:  #64748b;
  --radius:      0.5rem;
  --radius-lg:   1rem;
  --max-w:       1200px;
  --transition:  0.2s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-dark);
  background: var(--white);
}

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

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== TYPOGRAPHY ===== */
h1 { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800; line-height: 1.1; }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.5rem); font-weight: 700; line-height: 1.2; }
h3 { font-size: 1.25rem; font-weight: 600; }
h4 { font-size: 1rem; font-weight: 600; }

.section-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 0.75rem;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  border: 2px solid transparent;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.btn-primary {
  background: var(--orange);
  color: white;
}
.btn-primary:hover { background: var(--orange-dark); }
.btn-ghost {
  background: transparent;
  color: white;
  border-color: rgba(255,255,255,0.5);
}
.btn-ghost:hover { background: rgba(255,255,255,0.1); border-color: white; }
.btn-outline-orange {
  background: transparent;
  color: var(--orange);
  border-color: var(--orange);
}
.btn-outline-orange:hover { background: var(--orange); color: white; }

/* ===== NAVIGATION ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: white;
  box-shadow: 0 1px 0 var(--gray-200);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--text-dark);
}
.nav-logo-icon {
  width: 36px;
  height: 36px;
  background: var(--orange);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-600);
  transition: color var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--orange); }
.nav-right { display: flex; align-items: center; gap: 1rem; }
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-dark);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}
.mobile-menu {
  display: none;
  flex-direction: column;
  background: white;
  border-top: 1px solid var(--gray-200);
  padding: 1rem 1.5rem;
  gap: 1rem;
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  font-size: 1rem;
  font-weight: 500;
  color: var(--gray-600);
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--gray-100);
}
.mobile-menu a:hover { color: var(--orange); }

/* ===== HERO ===== */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #0f172a 0%, #1a2744 40%, #0f172a 100%);
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 70% 50%, rgba(249,115,22,0.12) 0%, transparent 70%),
    radial-gradient(ellipse 60% 80% at 20% 80%, rgba(139,92,246,0.1) 0%, transparent 70%);
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 620px;
  padding: 5rem 0;
}
.hero h1 { color: white; margin-bottom: 1.25rem; }
.hero h1 span { color: var(--orange); }
.hero p {
  color: rgba(255,255,255,0.75);
  font-size: 1.1rem;
  margin-bottom: 2rem;
  max-width: 500px;
}
.hero-buttons { display: flex; gap: 1rem; flex-wrap: wrap; }
.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255,255,255,0.4);
  font-size: 1.5rem;
  animation: bounce 2s infinite;
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(8px); }
}

/* ===== STATS ROW ===== */
.stats-row {
  background: white;
  padding: 3rem 0;
  border-bottom: 1px solid var(--gray-200);
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}
.stat-card {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.stat-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius);
  background: var(--orange-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}
.stat-value {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-dark);
  line-height: 1;
}
.stat-unit {
  font-size: 0.85rem;
  color: var(--orange);
  font-weight: 600;
  margin-left: 0.2rem;
}
.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

/* ===== SECTIONS (shared) ===== */
.section-light {
  background: var(--white);
  padding: 5rem 0;
}
.section-alt {
  background: var(--off-white);
  padding: 5rem 0;
}
.section-dark {
  background: var(--dark-navy);
  padding: 5rem 0;
  color: white;
}
.section-purple {
  background: linear-gradient(135deg, var(--dark-navy) 0%, var(--deep-purple) 100%);
  padding: 5rem 0;
  color: white;
}
.section-header {
  text-align: center;
  margin-bottom: 3rem;
}
.section-header p {
  color: var(--text-muted);
  margin-top: 0.75rem;
  font-size: 1.05rem;
}
.section-dark .section-header p,
.section-purple .section-header p {
  color: rgba(255,255,255,0.65);
}

/* ===== DEPARTMENT CARDS ===== */
.dept-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}
.dept-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--gray-200);
  transition: transform var(--transition), box-shadow var(--transition);
  background: white;
}
.dept-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.1);
}
.dept-card-image {
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
}
.dept-card-body { padding: 1rem 1.1rem 1.25rem; }
.dept-card-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 0.3rem;
}
.dept-card-body h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  color: var(--text-dark);
}
.dept-card-body p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 0.75rem;
}
.learn-more {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--orange);
}
.learn-more:hover { text-decoration: underline; }

/* ===== QUIZ SECTION ===== */
.quiz-inner {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 2rem;
  align-items: start;
}
.quiz-card {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-lg);
  padding: 2rem;
}
.quiz-card-icon {
  width: 56px;
  height: 56px;
  background: var(--orange);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1rem;
}
.quiz-card h3 { font-size: 1.3rem; margin-bottom: 0.5rem; }
.quiz-card p { color: rgba(255,255,255,0.65); margin-bottom: 1.25rem; }
.quiz-meta {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}
.quiz-meta-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.7);
}
.leaderboard-card {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}
.leaderboard-card h4 { margin-bottom: 1rem; font-size: 1rem; }
.leaderboard-entry {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  font-size: 0.85rem;
}
.leaderboard-entry:last-child { border-bottom: none; }
.rank { font-weight: 700; color: var(--orange); width: 1.5rem; }
.lb-name { flex: 1; }
.lb-score { font-weight: 600; }

/* ===== AMAZING FACTS ===== */
.facts-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.facts-list { display: flex; flex-direction: column; gap: 1.1rem; }
.fact-item {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
}
.fact-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--orange);
  flex-shrink: 0;
  margin-top: 0.45rem;
}
.fact-item p { font-size: 0.95rem; color: var(--gray-800); }
.facts-images {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto;
  gap: 1rem;
}
.fact-img {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: linear-gradient(135deg, #f3f4f6, #e5e7eb);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  padding: 2rem 1rem;
}
.fact-img.tall { grid-row: span 2; }
.fact-img.brain-img { background: linear-gradient(135deg, #ede9fe, #c4b5fd); }
.fact-img.heart-img { background: linear-gradient(135deg, #fce7f3, #f9a8d4); }
.fact-img.factory-img { background: linear-gradient(135deg, #e0f2fe, #7dd3fc); font-size: 3rem; }

/* ===== INTELLIGENT DESIGN ===== */
.intelligent-design {
  text-align: center;
  padding: 6rem 0;
  background: linear-gradient(180deg, var(--dark-navy) 0%, #0a0f1e 100%);
  color: white;
}
.intelligent-design h2 { margin-bottom: 0.75rem; }
.intelligent-design .subtitle {
  font-size: 1.15rem;
  color: rgba(255,255,255,0.6);
  max-width: 540px;
  margin: 0 auto;
}

/* ===== EVIDENCE SECTIONS ===== */
.evidence-card {
  background: var(--gray-100);
  border-left: 4px solid var(--orange);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-top: 1.5rem;
  font-style: italic;
  font-size: 1rem;
  color: var(--gray-800);
  line-height: 1.7;
}
.link-orange { color: var(--orange); font-weight: 600; text-decoration: underline; }

.dna-section {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 0;
}
.dna-text {
  background: white;
  padding: 5rem 3rem 5rem 0;
}
.dna-text h2 { margin-bottom: 1rem; }
.dna-text p { color: var(--text-muted); margin-bottom: 1rem; font-size: 0.95rem; }
.dna-stats {
  background: var(--dark-navy);
  padding: 5rem 2.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-content: center;
}
.dna-stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--orange);
  line-height: 1;
}
.dna-stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.6);
  margin-top: 0.3rem;
}

/* ===== EYES SECTION ===== */
.eyes-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.eyes-stats { display: flex; gap: 3rem; margin-bottom: 2.5rem; }
.eye-stat-value {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--orange);
  line-height: 1;
}
.eye-stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.6);
  margin-top: 0.2rem;
}
.eye-features { display: flex; flex-direction: column; gap: 1rem; }
.eye-feature {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  color: rgba(255,255,255,0.8);
}
.eye-feature-icon {
  width: 36px;
  height: 36px;
  background: rgba(249,115,22,0.2);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}
.eyes-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10rem;
  opacity: 0.85;
}

/* ===== IMMUNE SYSTEM ===== */
.immune-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}
.immune-text h2 { margin-bottom: 1rem; }
.immune-text p { color: var(--text-muted); margin-bottom: 1rem; font-size: 0.95rem; }
.immune-cards { display: flex; flex-direction: column; gap: 1rem; }
.immune-card {
  display: flex;
  gap: 1rem;
  padding: 1.25rem;
  border-radius: var(--radius);
  background: var(--gray-100);
  align-items: flex-start;
}
.immune-card-icon {
  width: 40px;
  height: 40px;
  background: var(--orange);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.immune-card h4 { margin-bottom: 0.25rem; font-size: 0.95rem; }
.immune-card p { font-size: 0.82rem; color: var(--text-muted); }

/* ===== BRAIN SECTION ===== */
.brain-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-top: 3rem;
  margin-bottom: 2rem;
}
.brain-stat { text-align: center; }
.brain-stat-value {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--orange);
  line-height: 1;
}
.brain-stat-unit {
  font-size: 1rem;
  font-weight: 700;
  color: var(--orange);
}
.brain-stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.55);
  margin-top: 0.3rem;
}
.brain-section-subtitle {
  text-align: center;
  color: rgba(255,255,255,0.6);
  font-size: 0.95rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== FOOTER ===== */
.footer {
  background: var(--gray-800);
  color: rgba(255,255,255,0.7);
  padding: 3rem 0 2rem;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}
.footer-brand p {
  font-size: 0.88rem;
  margin-top: 0.75rem;
  max-width: 300px;
  line-height: 1.6;
}
.footer-col h4 {
  color: white;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}
.footer-col ul { display: flex; flex-direction: column; gap: 0.6rem; }
.footer-col a {
  font-size: 0.85rem;
  transition: color var(--transition);
}
.footer-col a:hover { color: var(--orange); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
}

/* ===== QUIZ PAGE ===== */
.quiz-page {
  min-height: calc(100vh - 64px);
  background: linear-gradient(135deg, var(--dark-navy) 0%, var(--deep-purple) 100%);
  padding: 4rem 0;
  color: white;
}
.quiz-progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255,255,255,0.1);
  border-radius: 3px;
  margin-bottom: 2rem;
  overflow: hidden;
}
.quiz-progress-fill {
  height: 100%;
  background: var(--orange);
  border-radius: 3px;
  transition: width 0.4s ease;
}
.quiz-question-card {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  max-width: 700px;
  margin: 0 auto;
}
.quiz-q-number {
  font-size: 0.8rem;
  color: var(--orange);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}
.quiz-question-card h2 { font-size: 1.4rem; margin-bottom: 1.75rem; }
.quiz-options { display: flex; flex-direction: column; gap: 0.75rem; }
.quiz-option {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
}
.quiz-option:hover {
  background: rgba(249,115,22,0.15);
  border-color: rgba(249,115,22,0.4);
}
.quiz-option input[type="radio"] { accent-color: var(--orange); }
.quiz-option label { cursor: pointer; font-size: 0.95rem; }
.quiz-footer {
  margin-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.quiz-result {
  text-align: center;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-lg);
  padding: 3rem;
  max-width: 600px;
  margin: 0 auto;
}
.quiz-score-circle {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: var(--orange);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
}
.quiz-score-number { font-size: 2rem; font-weight: 800; line-height: 1; }
.quiz-score-total { font-size: 0.85rem; opacity: 0.85; }
.quiz-result h2 { margin-bottom: 0.75rem; }
.quiz-result p { color: rgba(255,255,255,0.65); margin-bottom: 1.5rem; }
.answer-correct { background: rgba(52,211,153,0.15); border-color: #34d399; }
.answer-wrong   { background: rgba(248,113,113,0.15); border-color: #f87171; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .dept-grid { grid-template-columns: repeat(3, 1fr); }
  .quiz-inner { grid-template-columns: 1fr; }
  .leaderboard-card { display: none; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-right .btn { display: none; }
  .hamburger { display: flex; }

  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .dept-grid { grid-template-columns: repeat(2, 1fr); }
  .facts-inner { grid-template-columns: 1fr; }
  .facts-images { display: none; }
  .dna-section { grid-template-columns: 1fr; }
  .dna-text { padding: 3rem 0; }
  .eyes-inner { grid-template-columns: 1fr; }
  .eyes-visual { display: none; }
  .immune-inner { grid-template-columns: 1fr; }
  .brain-stats { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; gap: 0.5rem; text-align: center; }
}

@media (max-width: 480px) {
  .dept-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 1rem; }
  .brain-stats { grid-template-columns: 1fr 1fr; }
  .hero-buttons { flex-direction: column; }
  .hero-buttons .btn { text-align: center; justify-content: center; }
}