/* ========================================================================
   ZULU — Your Aviation AI Assistant
   Design system matches the mobile app: deep navy + instrument amber
   ======================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&family=Instrument+Serif:ital@0;1&display=swap');

:root {
  --bg:        #080f1a;
  --bg2:      #0d1826;
  --bg3:      #111f30;
  --border:   #1a2a3a;
  --border-2: #243649;
  --amber:    #f5a623;
  --amber-dim:rgba(245,166,35,0.15);
  --amber-glow:rgba(245,166,35,0.35);
  --blue:     #3d9cf5;
  --blue-dim: rgba(61,156,245,0.15);
  --green:    #2dd4a0;
  --text:     #e8edf5;
  --text2:   #8a9bb0;
  --text3:   #4d6070;
  --danger:  #e05252;

  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body:    'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono:    'JetBrains Mono', ui-monospace, monospace;

  --max-width: 1200px;
  --radius: 14px;
  --radius-sm: 10px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Atmospheric gradient background */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(245,166,35,0.08), transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 10%, rgba(61,156,245,0.06), transparent 60%),
    radial-gradient(ellipse 60% 40% at 20% 90%, rgba(245,166,35,0.05), transparent 60%);
  pointer-events: none;
  z-index: -1;
}

/* Runway grid overlay */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(245,166,35,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245,166,35,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: -1;
  mask-image: radial-gradient(ellipse at center, black 20%, transparent 80%);
}

a { color: var(--amber); text-decoration: none; transition: opacity .2s; }
a:hover { opacity: 0.8; }

img { max-width: 100%; height: auto; display: block; }

/* =========== LAYOUT =========== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section { padding: 96px 0; position: relative; }

/* =========== NAV =========== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8,15,26,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 6px;
  color: var(--amber);
  text-decoration: none;
}
.logo-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--amber);
  border-radius: 50%;
  margin-left: 6px;
  vertical-align: middle;
  box-shadow: 0 0 12px var(--amber-glow);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
.nav-links {
  display: flex;
  gap: 32px;
  align-items: center;
  list-style: none;
}
.nav-links a {
  color: var(--text2);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.2px;
}
.nav-links a:hover { color: var(--text); opacity: 1; }
.nav-cta {
  background: var(--amber);
  color: #000 !important;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.3px;
}
.nav-cta:hover { opacity: 0.9 !important; }
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 24px;
  cursor: pointer;
  padding: 4px 8px;
}

/* =========== HERO =========== */
.hero {
  padding: 120px 0 96px;
  text-align: center;
  position: relative;
}
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--amber-dim);
  border: 1px solid var(--amber);
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 32px;
}
.hero-eyebrow::before {
  content: '';
  width: 6px;
  height: 6px;
  background: var(--amber);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--amber-glow);
}
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(48px, 8vw, 96px);
  font-weight: 400;
  line-height: 1.02;
  letter-spacing: -2px;
  margin-bottom: 24px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}
.hero h1 em {
  font-style: italic;
  color: var(--amber);
}
.hero-sub {
  font-size: clamp(17px, 2vw, 20px);
  color: var(--text2);
  max-width: 640px;
  margin: 0 auto 40px;
  line-height: 1.5;
}
.hero-ctas {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 28px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.3px;
  transition: transform .15s, box-shadow .15s;
  cursor: pointer;
  border: none;
  font-family: var(--font-body);
}
.btn-primary {
  background: var(--amber);
  color: #000;
  box-shadow: 0 8px 32px var(--amber-glow);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px var(--amber-glow);
  opacity: 1;
}
.btn-secondary {
  background: var(--bg2);
  color: var(--text);
  border: 1px solid var(--border-2);
}
.btn-secondary:hover {
  background: var(--bg3);
  transform: translateY(-2px);
  opacity: 1;
}

/* Stats strip */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 24px;
  max-width: 800px;
  margin: 0 auto;
  padding: 32px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.stat { text-align: center; }
.stat-num {
  font-family: var(--font-display);
  font-size: 40px;
  color: var(--amber);
  line-height: 1;
  display: block;
  margin-bottom: 6px;
}
.stat-label {
  font-size: 12px;
  color: var(--text2);
  letter-spacing: 1.2px;
  text-transform: uppercase;
}

/* =========== SECTION HEADERS =========== */
.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.section-eyebrow::before {
  content: '';
  width: 24px;
  height: 1px;
  background: var(--amber);
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(36px, 5vw, 56px);
  line-height: 1.1;
  letter-spacing: -1px;
  margin-bottom: 20px;
  font-weight: 400;
}
.section-title em { color: var(--amber); font-style: italic; }
.section-lead {
  font-size: 18px;
  color: var(--text2);
  max-width: 640px;
  margin-bottom: 56px;
}
.section-center { text-align: center; }
.section-center .section-eyebrow { justify-content: center; }
.section-center .section-lead { margin-left: auto; margin-right: auto; }

/* =========== FEATURES =========== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.feature-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color .2s, transform .2s;
  position: relative;
  overflow: hidden;
}
.feature-card:hover {
  border-color: var(--border-2);
  transform: translateY(-4px);
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 40px; height: 3px;
  background: var(--amber);
  border-radius: 0 0 3px 0;
}
.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background: var(--amber-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--amber);
  font-size: 22px;
}
.feature-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: -0.3px;
}
.feature-card p {
  color: var(--text2);
  font-size: 15px;
  line-height: 1.6;
}

/* =========== HOW IT WORKS =========== */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  counter-reset: step;
}
.step {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  position: relative;
  counter-increment: step;
}
.step::before {
  content: counter(step, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--amber);
  letter-spacing: 2px;
  display: block;
  margin-bottom: 16px;
}
.step h3 {
  font-size: 19px;
  margin-bottom: 10px;
  font-weight: 600;
  letter-spacing: -0.3px;
}
.step p {
  color: var(--text2);
  font-size: 15px;
}

/* =========== KNOWLEDGE BASE =========== */
.knowledge-wrap {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 48px;
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
  align-items: center;
}
.knowledge-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.chip {
  padding: 8px 14px;
  background: var(--bg3);
  border: 1px solid var(--border-2);
  border-radius: 100px;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--text);
  letter-spacing: 0.5px;
}
.chip-amber {
  background: var(--amber-dim);
  border-color: var(--amber);
  color: var(--amber);
}

/* =========== PRICING =========== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  max-width: 900px;
  margin: 0 auto;
}
.price-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 32px;
  position: relative;
}
.price-card.featured {
  border-color: var(--amber);
  box-shadow: 0 0 0 1px var(--amber), 0 20px 60px rgba(245,166,35,0.15);
}
.price-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--amber);
  color: #000;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  padding: 6px 14px;
  border-radius: 100px;
  text-transform: uppercase;
}
.price-tier {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.price {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 8px;
}
.price-num {
  font-family: var(--font-display);
  font-size: 56px;
  line-height: 1;
  color: var(--text);
}
.price-period { color: var(--text2); font-size: 15px; }
.price-sub {
  font-size: 13px;
  color: var(--text3);
  margin-bottom: 28px;
}
.price-features {
  list-style: none;
  margin-bottom: 28px;
}
.price-features li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--text);
}
.price-features li:last-child { border-bottom: none; }
.price-features li::before {
  content: '✓';
  color: var(--amber);
  font-weight: 700;
  flex-shrink: 0;
}
.price-features li.disabled {
  color: var(--text3);
}
.price-features li.disabled::before {
  content: '—';
  color: var(--text3);
}

/* =========== FAQ (AEO-critical) =========== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}
.faq-item {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  transition: border-color .2s;
}
.faq-item[open] {
  border-color: var(--amber);
}
.faq-item summary {
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  list-style: none;
  user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: '+';
  font-size: 24px;
  color: var(--amber);
  font-weight: 400;
  transition: transform .2s;
  flex-shrink: 0;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item .faq-a {
  padding: 0 24px 20px;
  color: var(--text2);
  font-size: 15px;
  line-height: 1.7;
}
.faq-item .faq-a p + p { margin-top: 12px; }

/* =========== CTA =========== */
.cta-banner {
  background: linear-gradient(135deg, var(--bg2), var(--bg3));
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 64px 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, var(--amber-dim), transparent 60%);
  pointer-events: none;
}
.cta-banner > * { position: relative; }
.cta-banner h2 {
  font-family: var(--font-display);
  font-size: clamp(32px, 4vw, 48px);
  margin-bottom: 16px;
  font-weight: 400;
  letter-spacing: -1px;
}
.cta-banner p {
  font-size: 17px;
  color: var(--text2);
  max-width: 520px;
  margin: 0 auto 32px;
}

/* =========== FOOTER =========== */
.footer {
  border-top: 1px solid var(--border);
  padding: 64px 0 40px;
  margin-top: 80px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-brand p {
  color: var(--text2);
  font-size: 14px;
  margin-top: 16px;
  max-width: 320px;
  line-height: 1.6;
}
.footer h4 {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--amber);
  text-transform: uppercase;
  margin-bottom: 16px;
}
.footer ul { list-style: none; }
.footer li { margin-bottom: 10px; }
.footer a {
  color: var(--text2);
  font-size: 14px;
  text-decoration: none;
}
.footer a:hover { color: var(--text); opacity: 1; }
.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--text3);
  font-size: 13px;
}
.footer-bottom p a { color: var(--text3); }

/* =========== CONTENT / LEGAL PAGES =========== */
.content-page {
  padding: 80px 0;
  max-width: 800px;
  margin: 0 auto;
}
.content-page h1 {
  font-family: var(--font-display);
  font-size: clamp(40px, 6vw, 64px);
  line-height: 1.05;
  margin-bottom: 16px;
  letter-spacing: -1px;
  font-weight: 400;
}
.content-page .lead {
  font-size: 18px;
  color: var(--text2);
  margin-bottom: 48px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}
.content-page h2 {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 400;
  letter-spacing: -0.5px;
  margin: 48px 0 16px;
  color: var(--amber);
}
.content-page h3 {
  font-size: 20px;
  font-weight: 600;
  margin: 32px 0 12px;
  color: var(--text);
}
.content-page p,
.content-page ul,
.content-page ol {
  margin-bottom: 16px;
  color: var(--text);
  font-size: 16px;
  line-height: 1.75;
}
.content-page ul, .content-page ol {
  padding-left: 24px;
}
.content-page li { margin-bottom: 8px; }
.content-page strong { color: var(--text); font-weight: 600; }
.content-page a { color: var(--amber); text-decoration: underline; text-underline-offset: 3px; }
.content-page .meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text3);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

/* Blog / article styling */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.article-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: block;
  color: var(--text);
  text-decoration: none;
  transition: border-color .2s, transform .2s;
}
.article-card:hover {
  border-color: var(--amber);
  transform: translateY(-3px);
  opacity: 1;
}
.article-card .tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--amber);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-bottom: 12px;
  display: block;
}
.article-card h3 {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 400;
  line-height: 1.25;
  margin-bottom: 10px;
  letter-spacing: -0.3px;
}
.article-card p {
  color: var(--text2);
  font-size: 14px;
  line-height: 1.55;
}

/* =========== UTILITIES =========== */
.text-amber { color: var(--amber); }
.text-muted { color: var(--text2); }
.mono { font-family: var(--font-mono); }

/* =========== RESPONSIVE =========== */
@media (max-width: 860px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav.open .nav-links {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
  }
  section { padding: 72px 0; }
  .hero { padding: 80px 0 64px; }
  .knowledge-wrap {
    grid-template-columns: 1fr;
    padding: 32px;
    gap: 32px;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
  .cta-banner { padding: 48px 24px; }
}
@media (max-width: 480px) {
  .container { padding: 0 20px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .hero-ctas { flex-direction: column; width: 100%; }
  .hero-ctas .btn { width: 100%; justify-content: center; }
}

/* =========== SCROLL ANIMATIONS =========== */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity .6s, transform .6s;
  }
  .reveal.in {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Feature tier badges (Free / Pro) */
.feature-tier {
  margin-top: 16px !important;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 11px !important;
  letter-spacing: 0.5px;
  color: var(--text2) !important;
}
.tier-free, .tier-pro {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-right: 6px;
}
.tier-free {
  background: var(--bg3);
  color: var(--text);
  border: 1px solid var(--border-2);
}
.tier-pro {
  background: var(--amber-dim);
  color: var(--amber);
  border: 1px solid var(--amber);
}