:root {
  --primary: #0f172a;
  --primary-light: #1e293b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --emerald: #059669;
  --emerald-bg: #ecfdf5;
  --amber: #d97706;
  --text: #0f172a;
  --text-muted: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --header-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  color: var(--text);
  background-color: var(--bg);
  line-height: 1.6;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
header {
  background: #ffffff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--header-shadow);
}

.nav-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--accent);
}

.logo-badge {
  font-size: 0.7rem;
  text-transform: uppercase;
  background: #eff6ff;
  color: var(--accent);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-weight: 700;
  letter-spacing: 0.05em;
  border: 1px solid #bfdbfe;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 1.8rem;
  align-items: center;
}

nav a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

nav a:hover, nav a.active {
  color: var(--accent);
  text-decoration: none;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: #ffffff;
  padding: 4.5rem 0 3.5rem;
  text-align: center;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.2rem;
  color: #94a3b8;
  max-width: 760px;
  margin: 0 auto 2rem;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  margin: 2.5rem auto 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
}

.stat-item h3 {
  font-size: 2rem;
  font-weight: 800;
  color: #38bdf8;
}

.stat-item p {
  font-size: 0.85rem;
  color: #94a3b8;
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Search Box */
.search-bar-wrap {
  max-width: 650px;
  margin: 0 auto;
  position: relative;
}

.search-input {
  width: 100%;
  padding: 1rem 1.25rem 1rem 3rem;
  font-size: 1.05rem;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.95);
  color: var(--primary);
  outline: none;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
}

.search-icon {
  position: absolute;
  left: 1.1rem;
  top: 50%;
  transform: translateY(-50%);
  color: #64748b;
  font-size: 1.2rem;
}

/* Main Content */
.section {
  padding: 4rem 0;
}

.section-alt {
  background-color: var(--bg-alt);
}

.section-header {
  margin-bottom: 2.5rem;
}

.section-header h2 {
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: -0.02em;
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Airport Grid */
.airport-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.airport-card {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  display: flex;
  flex-direction: column;
}

.airport-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--card-shadow);
  border-color: var(--accent);
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.8rem;
}

.iata-badge {
  font-size: 1.25rem;
  font-weight: 800;
  color: #ffffff;
  background: var(--primary);
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
  letter-spacing: 0.05em;
}

.region-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  background: #f1f5f9;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
}

.airport-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.25rem;
}

.airport-location {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.card-metrics {
  background: var(--bg-alt);
  border-radius: 6px;
  padding: 0.8rem;
  margin-bottom: 1.2rem;
  font-size: 0.88rem;
}

.metric-row {
  display: flex;
  justify-content: space-between;
  padding: 0.25rem 0;
  border-bottom: 1px dashed #e2e8f0;
}

.metric-row:last-child {
  border-bottom: none;
}

.metric-label {
  color: var(--text-muted);
}

.metric-val {
  font-weight: 700;
  color: var(--primary);
}

.card-btn {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: #eff6ff;
  color: var(--accent);
  padding: 0.65rem 1rem;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.9rem;
  border: 1px solid #bfdbfe;
  transition: all 0.15s ease;
}

.airport-card:hover .card-btn {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
  text-decoration: none;
}

/* Detail Page Elements */
.breadcrumb {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 1.25rem 0;
}

.citation-box {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-left: 5px solid var(--emerald);
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1.5rem 0 2.5rem;
}

.citation-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--emerald);
  margin-bottom: 0.6rem;
}

.citation-text {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.88rem;
  color: #166534;
  background: #ffffff;
  padding: 0.75rem 1rem;
  border-radius: 6px;
  border: 1px solid #dcfce7;
  word-break: break-all;
}

.grid-metrics-large {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin: 2rem 0;
}

.metric-box {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
}

.metric-box-title {
  font-size: 0.8rem;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.metric-box-num {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.2;
}

.metric-box-sub {
  font-size: 0.8rem;
  color: #64748b;
  margin-top: 0.35rem;
}

/* Monetization Callout Boxes */
.monetization-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
  margin: 2.5rem 0;
}

.promo-card {
  border-radius: 10px;
  padding: 1.5rem;
  border: 1px solid var(--border);
  background: #ffffff;
  display: flex;
  flex-direction: column;
}

.promo-compensation {
  background: linear-gradient(180deg, #eff6ff 0%, #ffffff 100%);
  border-color: #bfdbfe;
}

.promo-lounge {
  background: linear-gradient(180deg, #faf5ff 0%, #ffffff 100%);
  border-color: #e9d5ff;
}

.promo-parking {
  background: linear-gradient(180deg, #ecfdf5 0%, #ffffff 100%);
  border-color: #a7f3d0;
}

.promo-tag {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.promo-compensation .promo-tag { color: var(--accent); }
.promo-lounge .promo-tag { color: #7e22ce; }
.promo-parking .promo-tag { color: var(--emerald); }

.promo-card h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.promo-card p {
  font-size: 0.9rem;
  color: #475569;
  margin-bottom: 1.25rem;
}

.promo-btn {
  margin-top: auto;
  display: inline-block;
  text-align: center;
  padding: 0.7rem 1.2rem;
  border-radius: 6px;
  font-weight: 700;
  font-size: 0.9rem;
  color: #ffffff;
  transition: opacity 0.15s ease;
}

.promo-btn:hover {
  opacity: 0.9;
  text-decoration: none;
}

.btn-blue { background: var(--accent); }
.btn-purple { background: #7e22ce; }
.btn-green { background: var(--emerald); }

/* FAQ Accordion */
.faq-wrap {
  margin: 2rem 0;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 0.75rem;
  background: #ffffff;
}

.faq-question {
  padding: 1.1rem 1.25rem;
  font-weight: 700;
  color: var(--primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-answer {
  padding: 0 1.25rem 1.25rem;
  color: #475569;
  font-size: 0.95rem;
}

/* Footer */
footer {
  background: var(--primary);
  color: #94a3b8;
  padding: 4rem 0 2rem;
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-col h4 {
  color: #ffffff;
  font-size: 1rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 0.5rem;
}

.footer-col a {
  color: #94a3b8;
}

.footer-col a:hover {
  color: #ffffff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.8rem;
}

@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 1rem; }
  .nav-wrap { flex-direction: column; height: auto; padding: 1rem 0; gap: 0.75rem; }
  .grid-metrics-large { grid-template-columns: 1fr; }
}