/* roulang page: index */
:root {
      --primary: #0B2B26;
      --accent: #F5A623;
      --accent-hover: #E5941A;
      --bg-light: #F9FAFB;
      --white: #FFFFFF;
      --text-dark: #1F2937;
      --text-muted: #6B7280;
      --border-light: #E5E7EB;
      --bg-faq: #F3F4F6;
      --shadow-card: 0 8px 30px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-lg: 32px;
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-faq: 12px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --transition-base: 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* Header & Navigation */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background-color: var(--white);
      border-bottom: 1px solid transparent;
      transition: border-color 0.2s;
      height: 72px;
      display: flex;
      align-items: center;
    }

    .site-header.scrolled {
      border-bottom-color: var(--border-light);
      box-shadow: 0 4px 10px rgba(0,0,0,0.02);
    }

    .navbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo i {
      color: var(--accent);
      font-size: 1.8rem;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      font-weight: 500;
      color: var(--text-dark);
      font-size: 0.98rem;
      position: relative;
      padding: 6px 0;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: width 0.25s ease;
    }

    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }

    .nav-link:hover {
      color: var(--primary);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      background: transparent;
      border: none;
      gap: 6px;
    }

    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--primary);
      border-radius: 5px;
      transition: 0.3s;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(12px);
      flex-direction: column;
      padding: 32px 24px;
      gap: 24px;
      z-index: 40;
      text-align: center;
      border-bottom: 1px solid var(--border-light);
    }

    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 600;
      color: var(--primary);
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      gap: 48px;
      padding: 60px 0 80px;
      background: var(--bg-light);
    }

    .hero-content {
      flex: 1 1 50%;
    }

    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero .subtitle {
      font-size: 18px;
      color: #4B5563;
      margin-bottom: 32px;
      max-width: 480px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.25s;
      cursor: pointer;
      border: none;
      font-size: 1rem;
    }

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

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(245,166,35,0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }

    .btn-outline:hover {
      background: rgba(11,43,38,0.05);
    }

    .hero-image {
      flex: 1 1 50%;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: 0 20px 35px rgba(0,0,0,0.08);
    }

    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    /* Sections */
    section {
      padding: 80px 0;
    }

    .bg-dark {
      background-color: var(--primary);
      color: white;
    }

    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--primary);
    }

    .bg-dark .section-title {
      color: white;
    }

    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
      margin-bottom: 48px;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.2s;
      border: 1px solid transparent;
    }

    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }

    .card-icon {
      font-size: 2.2rem;
      color: var(--accent);
      margin-bottom: 20px;
    }

    .card h3 {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 10px;
    }

    .stat-badge-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 24px;
    }

    .stat-item {
      text-align: center;
      padding: 20px;
    }

    .stat-number {
      font-size: 2.4rem;
      font-weight: 800;
      color: white;
    }

    .stat-label {
      color: #CBD5E1;
      font-size: 0.9rem;
    }

    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-card);
      position: relative;
    }

    .quote-mark {
      font-size: 3rem;
      color: var(--accent);
      font-weight: 700;
      line-height: 1;
    }

    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: var(--bg-faq);
      border-radius: var(--radius-faq);
      margin-bottom: 12px;
      border: 1px solid transparent;
    }

    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    .faq-answer {
      padding: 0 24px 18px;
      color: var(--text-muted);
      display: none;
    }

    .faq-item.active {
      border-color: var(--primary);
      background: white;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    .cta-form {
      display: flex;
      gap: 12px;
      max-width: 500px;
      margin: 24px auto 0;
    }

    .cta-input {
      flex: 1;
      padding: 14px 24px;
      border-radius: 50px;
      border: none;
      background: white;
      box-shadow: inset 0 2px 6px rgba(0,0,0,0.04);
    }

    .footer {
      background: #1F2937;
      color: #E5E7EB;
      padding: 60px 0 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .hero { gap: 32px; }
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .hero { flex-direction: column; text-align: center; }
      .hero h1 { font-size: 36px; }
      .grid-3 { grid-template-columns: 1fr; }
      .testimonial-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .cta-form { flex-direction: column; }
      .stat-badge-grid { flex-direction: column; }
    }