:root {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-card: #1e1e35;
  --bg-card-hover: #252542;
  --text-primary: #e8e6f0;
  --text-secondary: #a09db0;
  --text-muted: #6b6880;
  --accent: #f59e0b;
  --accent-hover: #fbbf24;
  --accent-dim: rgba(245, 158, 11, 0.15);
  --danger: #ef4444;
  --danger-dim: rgba(239, 68, 68, 0.15);
  --warning: #f59e0b;
  --warning-dim: rgba(245, 158, 11, 0.15);
  --success: #22c55e;
  --success-dim: rgba(34, 197, 94, 0.15);
  --border: #2a2a40;
  --border-light: #3a3a55;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --max-width: 1120px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

a { color: var(--accent); text-decoration: none; }
a:hover, a:focus { color: var(--accent-hover); text-decoration: underline; }

img, svg { max-width: 100%; height: auto; }

/* Header */
.site-header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-primary);
  text-decoration: none;
}

.logo:hover, .logo:focus {
  color: var(--accent);
  text-decoration: none;
}

.logo-icon { width: 28px; height: 28px; color: var(--accent); }

.main-nav { display: flex; gap: 24px; }
.main-nav a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}
.main-nav a:hover, .main-nav a:focus {
  color: var(--accent);
  border-bottom-color: var(--accent);
  text-decoration: none;
}

/* Hero */
.hero-section {
  padding: 60px 0 40px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero-section h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 32px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
}

.stat { text-align: center; }
.stat-number {
  display: block;
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent);
}
.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Tracker Section */
.tracker-section { padding: 40px 0 60px; }
.tracker-section h2 {
  font-size: 1.6rem;
  margin-bottom: 24px;
}

.tracker-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
  align-items: start;
}

@media (max-width: 860px) {
  .tracker-layout { grid-template-columns: 1fr; }
  .dot-diagram { order: -1; }
}

/* Form */
.tracker-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.form-group {
  margin-bottom: 20px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 520px) {
  .form-row { grid-template-columns: 1fr; }
}

label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.label-hint {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.8em;
}

input, select {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: var(--font);
  transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

input::placeholder { color: var(--text-muted); }

.field-help {
  display: block;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.form-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  border: none;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s;
}

.btn-primary {
  background: var(--accent);
  color: #1a1a2e;
}

.btn-primary:hover, .btn-primary:focus {
  background: var(--accent-hover);
  box-shadow: 0 2px 12px rgba(245, 158, 11, 0.3);
}

.btn-secondary {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover, .btn-secondary:focus {
  background: var(--border-light);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-ghost:hover, .btn-ghost:focus {
  color: var(--accent);
  border-color: var(--accent);
}

.btn-sm { padding: 6px 14px; font-size: 0.8rem; }

.btn-danger {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--danger);
}

.btn-danger:hover, .btn-danger:focus {
  background: var(--danger-dim);
}

/* DOT Diagram */
.dot-diagram {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
}

.dot-diagram h3 {
  font-size: 1rem;
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.tire-svg { margin-bottom: 12px; }

.dot-diagram p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* Results */
.results-area {
  margin-top: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.results-area h3 {
  font-size: 1.2rem;
  margin-bottom: 20px;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.result-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  text-align: center;
}

.result-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}

.result-value {
  display: block;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* Recommendation */
.recommendation {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px;
  border-radius: var(--radius-sm);
  margin-bottom: 24px;
}

.recommendation.status-ok {
  background: var(--success-dim);
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.recommendation.status-warn {
  background: var(--warning-dim);
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.recommendation.status-danger {
  background: var(--danger-dim);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.rec-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  line-height: 1;
}

.status-ok .rec-icon::before { content: "✓"; color: var(--success); }
.status-warn .rec-icon::before { content: "⚠"; color: var(--warning); }
.status-danger .rec-icon::before { content: "✕"; color: var(--danger); }

.rec-content h4 {
  font-size: 1rem;
  margin-bottom: 4px;
}

.rec-content p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Comparison Table */
.comparison-table {
  margin-bottom: 24px;
}

.comparison-table h4 {
  font-size: 0.95rem;
  margin-bottom: 12px;
  color: var(--text-secondary);
}

.comparison-table table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.comparison-table th {
  text-align: left;
  padding: 10px 12px;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border);
}

.comparison-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
}

.status-badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 600;
}

.badge-ok { background: var(--success-dim); color: var(--success); }
.badge-warn { background: var(--warning-dim); color: var(--warning); }
.badge-danger { background: var(--danger-dim); color: var(--danger); }

.result-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

/* Vehicles Section */
.vehicles-section { padding: 40px 0; background: var(--bg-secondary); }
.vehicles-section h2 { font-size: 1.4rem; margin-bottom: 24px; }

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.section-header h2 { margin-bottom: 0; }

.vehicles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.vehicle-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: border-color 0.2s;
}

.vehicle-card:hover { border-color: var(--border-light); }

.vehicle-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.vehicle-name {
  font-weight: 700;
  font-size: 1.05rem;
}

.vehicle-card-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 16px;
  font-size: 0.85rem;
  margin-bottom: 16px;
}

.vehicle-stat-label { color: var(--text-muted); font-size: 0.75rem; }
.vehicle-stat-value { color: var(--text-primary); font-weight: 600; }

.vehicle-actions {
  display: flex;
  gap: 8px;
}

.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 40px;
  color: var(--text-muted);
}

.empty-state svg {
  width: 48px;
  height: 48px;
  margin-bottom: 12px;
}

/* Guide Section */
.guide-section { padding: 60px 0; }
.guide-section h2 {
  font-size: 1.6rem;
  margin-bottom: 32px;
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 24px;
}

.guide-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.guide-card h3 {
  font-size: 1.05rem;
  margin-bottom: 12px;
  color: var(--accent);
}

.guide-card p, .guide-card li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.guide-card ul {
  list-style: none;
  padding: 0;
}

.guide-card li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}

.guide-card li:last-child { border-bottom: none; }

.guide-card strong { color: var(--text-primary); }

/* Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 40px 0 20px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 32px;
  align-items: start;
  margin-bottom: 32px;
}

@media (max-width: 700px) {
  .footer-grid { grid-template-columns: 1fr; gap: 20px; }
}

.footer-brand p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 8px;
  max-width: 300px;
}

.footer-brand .logo { color: var(--text-primary); }

.footer-nav, .footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-nav a, .footer-links a {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.footer-nav a:hover, .footer-links a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 16px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Focus styles */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Print */
@media print {
  .site-header, .site-footer, .form-actions, .result-actions, .btn { display: none; }
  body { background: #fff; color: #000; }
  .results-area, .tracker-form { border: 1px solid #ccc; background: #fff; }
}

/* Hidden utility */
[hidden] { display: none !important; }

/* Update mileage modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 20px;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  max-width: 400px;
  width: 100%;
}

.modal h3 { margin-bottom: 16px; font-size: 1.1rem; }

.modal-actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}


/* Factory-injected deployment helpers. The AI owns the site design above this block. */
.ad-unit {
  width: min(100%, 720px);
  min-height: 120px;
  margin: 24px auto;
  display: block;
}

.legal-page {
  width: min(900px, calc(100% - 32px));
  margin: 40px auto;
}

.factory-fallback-nav {
  width: min(900px, calc(100% - 32px));
  margin: 24px auto 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  font-size: 0.95rem;
}

.factory-fallback-nav a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}