/* ===== Variables ===== */
:root {
  --primary: #1a56db;
  --primary-dark: #1340a8;
  --primary-light: #e8effc;
  --accent: #f59e0b;
  --dark: #111827;
  --gray-900: #1f2937;
  --gray-700: #374151;
  --gray-500: #6b7280;
  --gray-300: #d1d5db;
  --gray-100: #f3f4f6;
  --white: #ffffff;
  --bg: #f9fafb;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 20px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.1);
  --transition: all 0.3s ease;
  --max-w: 1200px;
}

/* ===== Reset ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-900);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; font-family: inherit; }

/* ===== Utility ===== */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; }
.section-title {
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  color: var(--dark);
}
.section-subtitle {
  text-align: center;
  color: var(--gray-500);
  font-size: 16px;
  margin-bottom: 48px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-primary {
  background: var(--primary);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(26,86,219,0.3);
}
.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}
.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
}
.btn-white {
  background: var(--white);
  color: var(--primary);
}
.btn-white:hover {
  background: var(--gray-100);
  transform: translateY(-2px);
}
.btn-lg { padding: 16px 36px; font-size: 18px; }
.text-primary { color: var(--primary); }
.text-accent { color: var(--accent); }
.bg-light { background: var(--bg); }

/* ===== Header / Nav ===== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: var(--transition);
}
.header.scrolled {
  border-bottom-color: var(--gray-300);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--dark);
}
.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--primary);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 18px;
  font-weight: 900;
}
.logo span { color: var(--primary); }
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--gray-700);
  transition: var(--transition);
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}
.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}
.nav-cta {
  padding: 10px 24px !important;
  background: var(--primary);
  color: var(--white) !important;
  border-radius: var(--radius-sm);
  font-weight: 600 !important;
}
.nav-cta::after { display: none !important; }
.nav-cta:hover {
  background: var(--primary-dark) !important;
  color: var(--white) !important;
}

/* Mobile menu */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  padding: 8px;
}
.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--dark);
  transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, #f0f5ff 0%, #e8effc 50%, #f9fafb 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(26,86,219,0.08) 0%, transparent 70%);
  border-radius: 50%;
}
.hero .container {
  display: flex;
  align-items: center;
  gap: 60px;
}
.hero-content { flex: 1; }
.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(26,86,219,0.1);
  color: var(--primary);
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 20px;
}
.hero h1 {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  color: var(--dark);
}
.hero h1 span { color: var(--primary); }
.hero p {
  font-size: 18px;
  color: var(--gray-500);
  margin-bottom: 32px;
  max-width: 480px;
}
.hero-actions {
  display: flex;
  gap: 16px;
  margin-bottom: 40px;
}
.hero-stats {
  display: flex;
  gap: 40px;
}
.hero-stat strong {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--dark);
}
.hero-stat span {
  font-size: 14px;
  color: var(--gray-500);
}
.hero-visual {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-car-showcase {
  width: 100%;
  max-width: 500px;
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--white);
  position: relative;
  overflow: hidden;
}
.hero-car-showcase::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -30%;
  width: 200px;
  height: 200px;
  background: rgba(255,255,255,0.1);
  border-radius: 50%;
}
.hero-car-icon {
  font-size: 80px;
  margin-bottom: 16px;
}
.hero-car-showcase h3 {
  font-size: 24px;
  font-weight: 700;
}
.hero-car-showcase p {
  color: rgba(255,255,255,0.8);
  font-size: 14px;
}

/* ===== Features / Advantages ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  border: 1px solid var(--gray-100);
  transition: var(--transition);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-light);
}
.feature-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  background: var(--primary-light);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
}
.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}
.feature-card p {
  font-size: 14px;
  color: var(--gray-500);
  line-height: 1.6;
}

/* ===== Car Cards ===== */
.cars-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.car-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--gray-100);
  transition: var(--transition);
}
.car-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.car-img {
  width: 100%;
  aspect-ratio: 16/10;
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  color: var(--gray-300);
  position: relative;
  background-size: cover;
  background-position: center;
}
.car-tag {
  position: absolute;
  top: 12px;
  left: 12px;
  padding: 4px 12px;
  background: var(--primary);
  color: var(--white);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
}
.car-info { padding: 20px; }
.car-info h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.car-meta {
  display: flex;
  gap: 16px;
  margin-bottom: 12px;
  font-size: 13px;
  color: var(--gray-500);
}
.car-price {
  display: flex;
  align-items: baseline;
  gap: 4px;
}
.car-price strong {
  font-size: 24px;
  color: var(--primary);
  font-weight: 800;
}
.car-price span { font-size: 13px; color: var(--gray-500); }

/* Cars page filter */
.filter-bar {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}
.filter-btn {
  padding: 8px 24px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  background: var(--gray-100);
  color: var(--gray-700);
  transition: var(--transition);
}
.filter-btn:hover,
.filter-btn.active {
  background: var(--primary);
  color: var(--white);
}

/* ===== Store Cards ===== */
.stores-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.store-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--gray-100);
  transition: var(--transition);
}
.store-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-light);
}
.store-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.store-card h3::before {
  content: '';
  width: 4px;
  height: 20px;
  background: var(--primary);
  border-radius: 2px;
}
.store-detail {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  margin-bottom: 8px;
  font-size: 14px;
  color: var(--gray-500);
}
.store-detail i { margin-top: 3px; }

/* ===== Dev Services ===== */
.dev-hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, var(--dark) 0%, #1e3a5f 100%);
  color: var(--white);
  text-align: center;
}
.dev-hero h1 {
  font-size: 44px;
  font-weight: 800;
  margin-bottom: 16px;
}
.dev-hero p {
  font-size: 18px;
  color: rgba(255,255,255,0.7);
  max-width: 600px;
  margin: 0 auto 32px;
}
.dev-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.dev-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px;
  transition: var(--transition);
}
.dev-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.dev-card-icon {
  width: 56px;
  height: 56px;
  background: var(--primary-light);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 16px;
}
.dev-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.dev-card p { font-size: 14px; color: var(--gray-500); line-height: 1.7; }
.dev-card ul {
  margin-top: 12px;
  list-style: none;
}
.dev-card ul li {
  padding: 4px 0;
  font-size: 14px;
  color: var(--gray-700);
}
.dev-card ul li::before {
  content: "\2713";
  color: var(--primary);
  font-weight: 700;
  margin-right: 8px;
}

/* Tech stack */
.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}
.tech-tag {
  padding: 8px 20px;
  background: var(--gray-100);
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-700);
  transition: var(--transition);
}
.tech-tag:hover {
  background: var(--primary-light);
  color: var(--primary);
}

/* Process steps */
.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
}
.process-step {
  text-align: center;
  position: relative;
}
.step-number {
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 800;
  margin: 0 auto 16px;
}
.process-step h3 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.process-step p { font-size: 13px; color: var(--gray-500); }

/* ===== About ===== */
.about-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.about-text h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 16px;
}
.about-text p {
  color: var(--gray-500);
  margin-bottom: 16px;
  line-height: 1.8;
}
.about-image {
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, var(--primary-light) 0%, #dbeafe 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 64px;
}
.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.stat-card {
  text-align: center;
  padding: 32px 16px;
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--gray-100);
}
.stat-card strong {
  display: block;
  font-size: 36px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 4px;
}
.stat-card span { font-size: 14px; color: var(--gray-500); }

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}
.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.contact-icon {
  width: 48px;
  height: 48px;
  background: var(--primary-light);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}
.contact-item h4 { font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.contact-item p { font-size: 14px; color: var(--gray-500); }

.contact-form {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px;
  border: 1px solid var(--gray-100);
}
.form-group { margin-bottom: 16px; }
.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 6px;
}
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
  transition: var(--transition);
  outline: none;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26,86,219,0.1);
}
.form-group textarea { resize: vertical; min-height: 100px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* ===== CTA Banner ===== */
.cta-banner {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: var(--white);
  text-align: center;
}
.cta-banner h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 12px;
}
.cta-banner p {
  font-size: 18px;
  opacity: 0.85;
  margin-bottom: 32px;
}
.cta-actions { display: flex; gap: 16px; justify-content: center; }

/* ===== Footer ===== */
.footer {
  background: var(--dark);
  color: rgba(255,255,255,0.7);
  padding: 60px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer-brand .logo { color: var(--white); margin-bottom: 12px; }
.footer-brand .logo-icon { background: var(--primary); }
.footer-brand p { font-size: 14px; line-height: 1.7; }
.footer-col h4 {
  color: var(--white);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
}
.footer-col a {
  display: block;
  padding: 4px 0;
  font-size: 14px;
  color: rgba(255,255,255,0.6);
  transition: var(--transition);
}
.footer-col a:hover { color: var(--white); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}
.footer-bottom a { color: rgba(255,255,255,0.5); }
.footer-bottom a:hover { color: var(--white); }

/* ===== Page Header (inner pages) ===== */
.page-header {
  padding: 120px 0 40px;
  background: var(--bg);
  text-align: center;
}
.page-header h1 {
  font-size: 36px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 8px;
}
.page-header p {
  color: var(--gray-500);
  font-size: 16px;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .features-grid,
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .hero .container { flex-direction: column; text-align: center; }
  .hero p { margin: 0 auto 32px; }
  .hero-actions { justify-content: center; }
  .hero-stats { justify-content: center; }
  .hero-visual { order: -1; }
  .about-intro { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .dev-features { grid-template-columns: repeat(2, 1fr); }
  .process-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .section { padding: 60px 0; }
  .section-title { font-size: 26px; }
  .hero h1 { font-size: 32px; }
  .hero { padding: 120px 0 60px; }

  .nav-links {
    position: fixed;
    top: 72px;
    left: 0; right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--gray-300);
    transform: translateY(-120%);
    opacity: 0;
    transition: var(--transition);
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
  }
  .menu-toggle { display: flex; }

  .features-grid { grid-template-columns: 1fr; }
  .cars-grid { grid-template-columns: 1fr; }
  .stores-grid { grid-template-columns: 1fr; }
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { flex-direction: column; gap: 16px; align-items: center; }
  .hero-actions { flex-direction: column; align-items: center; }
  .dev-features { grid-template-columns: 1fr; }
  .process-steps { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .cta-actions { flex-direction: column; align-items: center; }
  .cta-banner h2 { font-size: 28px; }
  .dev-hero h1 { font-size: 30px; }
  .page-header { padding: 100px 0 30px; }
}