/* roulang page: index */
:root {
      --primary: #E63946;
      --primary-dark: #C1121F;
      --secondary: #1D3557;
      --accent: #F4A261;
      --bg: #F8F9FA;
      --text: #2B2D42;
      --text-light: #8D99AE;
      --border: #E8ECF1;
      --shadow-sm: 0 4px 16px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }
    body {
      font-family: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .font-number {
      font-family: 'Inter', 'Noto Sans SC', sans-serif;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      color: var(--secondary);
    }
    p {
      margin-bottom: 1.2rem;
      color: var(--text);
      font-size: 1rem;
      line-height: 1.8;
    }
    .section-title {
      font-size: 1.75rem;
      margin-bottom: 0.5rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 40px;
      height: 4px;
      background-color: var(--primary);
      border-radius: 2px;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    /* nav */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: white;
      box-shadow: 0 2px 20px rgba(0,0,0,0.06);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      text-decoration: none;
    }
    .logo span {
      background: var(--secondary);
      color: white;
      padding: 0.2rem 0.6rem;
      border-radius: 6px;
      font-size: 0.8rem;
      font-family: 'Inter', sans-serif;
      letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      font-size: 0.9375rem;
      font-weight: 500;
      color: var(--text);
      text-decoration: none;
      padding: 0.5rem 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    .nav-links a:hover {
      border-bottom-color: var(--primary);
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 600;
      padding: 0.625rem 1.5rem;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      font-weight: 600;
      padding: 0.625rem 1.5rem;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: white;
      color: var(--secondary);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      color: var(--text);
      padding: 0.5rem;
    }
    /* hero */
    #hero {
      min-height: 100vh;
      background: linear-gradient(rgba(29,53,87,0.85), rgba(29,53,87,0.8)), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      padding-top: 72px;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 2.5rem;
      line-height: 1.2;
      color: white;
      font-weight: 800;
      letter-spacing: -0.5px;
      margin-bottom: 1.5rem;
    }
    .hero-left p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.9);
      margin-bottom: 2rem;
    }
    .hero-cta {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .countdown-card {
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(12px);
      border-radius: 16px;
      padding: 2rem;
      text-align: center;
      color: white;
      border: 1px solid rgba(255,255,255,0.2);
    }
    .countdown-timer {
      display: flex;
      justify-content: center;
      gap: 1.5rem;
      font-family: 'Inter', sans-serif;
    }
    .countdown-item {
      text-align: center;
    }
    .countdown-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--accent);
      line-height: 1;
    }
    .countdown-label {
      font-size: 0.9rem;
      color: rgba(255,255,255,0.8);
      text-transform: uppercase;
    }
    /* metrics */
    #metrics {
      padding: 5rem 0;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 1.5rem;
      margin-top: 2.5rem;
    }
    .metric-card {
      background: white;
      border-radius: var(--radius);
      padding: 2rem 1.5rem;
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .metric-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .metric-number {
      font-size: 2.75rem;
      font-weight: 800;
      color: var(--primary);
      font-family: 'Inter', sans-serif;
    }
    .metric-label {
      color: var(--text-light);
      margin-top: 0.5rem;
      font-size: 0.95rem;
    }
    /* services */
    #services {
      padding: 5rem 0;
      background: white;
    }
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 2rem;
      margin-top: 2.5rem;
    }
    .service-card {
      background: white;
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 2rem;
      transition: all 0.25s;
    }
    .service-card:hover {
      border-color: var(--primary);
      box-shadow: 0 12px 24px -12px rgba(230,57,70,0.15);
    }
    .service-icon {
      width: 48px;
      height: 48px;
      background: #F8F9FA;
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      margin-bottom: 1.25rem;
    }
    .service-card h3 {
      font-size: 1.25rem;
      margin-bottom: 0.5rem;
    }
    .service-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 0.25rem;
      margin-top: 1rem;
      transition: gap 0.2s;
      text-decoration: none;
    }
    .service-link:hover {
      gap: 0.5rem;
    }
    /* comparison */
    #comparison {
      padding: 5rem 0;
    }
    .comparison-wrapper {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 1rem;
      margin-top: 2.5rem;
    }
    .compare-card {
      flex: 1;
      max-width: 45%;
      padding: 2rem;
      border-radius: var(--radius);
    }
    .compare-left {
      background: #EDF2F7;
    }
    .compare-right {
      background: #FFF5F5;
      border: 2px solid var(--primary);
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      margin: 1rem 0;
    }
    .vs-badge {
      width: 56px;
      height: 56px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.2rem;
      flex-shrink: 0;
    }
    /* faq */
    #faq {
      padding: 5rem 0;
      background: white;
    }
    .faq-list {
      max-width: 800px;
      margin: 2.5rem auto 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      padding: 1.25rem 0;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      color: var(--text);
      line-height: 1.8;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1.25rem;
    }
    .faq-icon {
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* contact */
    #contact {
      padding: 5rem 0;
    }
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      margin-top: 2rem;
    }
    .form-group {
      margin-bottom: 1.25rem;
    }
    input, select {
      width: 100%;
      height: 48px;
      border: 1px solid #D1D8E0;
      border-radius: 8px;
      padding: 0 1rem;
      font-size: 0.95rem;
      background: white;
      transition: 0.2s;
    }
    input:focus, select:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(230,57,70,0.1);
      outline: none;
    }
    .trust-badges {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      margin-top: 1.5rem;
    }
    .badge {
      background: #f1f5f9;
      padding: 0.5rem 1rem;
      border-radius: 30px;
      font-size: 0.85rem;
      color: var(--secondary);
      display: flex;
      align-items: center;
      gap: 0.3rem;
    }
    /* footer */
    #footer {
      background: var(--secondary);
      color: rgba(255,255,255,0.7);
      padding: 4rem 0 2rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2.5rem;
    }
    .footer-brand {
      font-size: 1.3rem;
      font-weight: 700;
      color: white;
      margin-bottom: 1rem;
    }
    .footer-links a {
      color: rgba(255,255,255,0.7);
      text-decoration: none;
      display: block;
      margin: 0.4rem 0;
      transition: color 0.2s;
    }
    .footer-links a:hover {
      color: var(--accent);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 2.5rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.9rem;
    }
    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .services-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: var(--secondary);
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2rem;
        z-index: 99;
        transform: translateX(100%);
        transition: transform 0.3s ease;
      }
      .mobile-menu.open {
        transform: translateX(0);
      }
      .mobile-menu a {
        color: white;
        font-size: 1.5rem;
        text-decoration: none;
      }
      .metrics-grid {
        grid-template-columns: repeat(2,1fr);
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .comparison-wrapper {
        flex-direction: column;
      }
      .compare-card {
        max-width: 100%;
        width: 100%;
      }
      .contact-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 480px) {
      .metrics-grid {
        grid-template-columns: 1fr;
      }
      .countdown-timer {
        gap: 0.8rem;
      }
    }