/* roulang page: index */
* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    :root {
      --primary: #FF6B4A;
      --primary-dark: #E55A3D;
      --primary-light: #FFF0EC;
      --accent-green: #00B897;
      --deep-bg: #1E1E2C;
      --warm-bg: #F7F5F2;
      --gray-text: #6B7280;
      --dark-text: #1E1E2C;
      --white: #ffffff;
      --card-shadow: 0 2px 12px rgba(0,0,0,0.04);
      --card-hover-shadow: 0 8px 24px rgba(0,0,0,0.08);
      --border-light: #E5E7EB;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --section-gap: 120px;
      --font-h1: clamp(32px, 6vw, 52px);
      --font-h2: clamp(24px, 4vw, 34px);
      --font-h3: clamp(20px, 2.5vw, 24px);
      --font-body: 16px;
      --transition-smooth: 0.2s ease;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', system-ui, -apple-system, sans-serif;
      background-color: var(--warm-bg);
      color: var(--dark-text);
      line-height: 1.8;
      font-size: var(--font-body);
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
      :root {
        --section-gap: 80px;
      }
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    /* Header / Navigation */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background-color: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      height: 64px;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
    }
    .logo-icon {
      font-size: 26px;
    }
    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .desktop-nav a {
      font-size: 15px;
      font-weight: 500;
      color: #4B5563;
      transition: color var(--transition-smooth);
      position: relative;
    }
    .desktop-nav a:hover {
      color: var(--primary);
    }
    .desktop-nav a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition-smooth);
    }
    .desktop-nav a:hover::after {
      width: 100%;
    }
    .btn-nav {
      background: var(--primary);
      color: white !important;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition-smooth);
    }
    .btn-nav:hover {
      background: var(--primary-dark);
    }
    .btn-nav::after {
      display: none;
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--dark-text);
      cursor: pointer;
    }
    .mobile-nav {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 36px;
      z-index: 99;
      font-size: 20px;
      font-weight: 500;
    }
    .mobile-nav.active {
      display: flex;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
    }

    /* Buttons */
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      min-height: 48px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: background var(--transition-smooth), transform var(--transition-smooth);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      min-height: 48px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: all var(--transition-smooth);
    }
    .btn-outline:hover {
      background: var(--primary-light);
      border-color: var(--primary);
    }
    .btn-white {
      background: white;
      color: var(--primary);
      border: none;
      font-weight: 700;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-size: 18px;
      transition: background var(--transition-smooth);
    }
    .btn-white:hover {
      background: #f3f4f6;
    }

    /* Hero Section */
    .hero-section {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      padding: 80px 0;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: var(--font-h1);
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: var(--deep-bg);
    }
    .highlight {
      color: var(--primary);
      position: relative;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--gray-text);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 360px;
      border-radius: 20px;
      box-shadow: var(--card-hover-shadow);
      position: relative;
      transform: perspective(800px) rotateY(-2deg);
      transition: transform 0.3s;
    }
    @media (max-width: 1024px) {
      .hero-section {
        flex-direction: column;
        text-align: center;
      }
      .hero-text {
        display: flex;
        flex-direction: column;
        align-items: center;
      }
      .hero-sub {
        max-width: 100%;
      }
      .hero-image {
        width: 100%;
        height: 280px;
      }
    }

    /* Section titles */
    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-title h2 {
      font-size: var(--font-h2);
      font-weight: 600;
      color: var(--deep-bg);
    }
    .section-title p {
      color: var(--gray-text);
      margin-top: 12px;
    }

    /* Features Grid (asymmetric) */
    .features-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr;
      gap: 24px;
      margin-top: 20px;
    }
    .feature-card {
      background: white;
      padding: 32px 28px;
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      transition: all var(--transition-smooth);
      display: flex;
      flex-direction: column;
      align-items: flex-start;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-hover-shadow);
    }
    .feature-icon {
      font-size: 40px;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: var(--font-h3);
      font-weight: 600;
      margin-bottom: 12px;
    }
    .feature-card p {
      color: var(--gray-text);
      flex: 1;
    }
    @media (max-width: 1024px) {
      .features-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 640px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

    /* Scenarios */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      background-size: cover;
      background-position: center;
      border-radius: 16px;
      min-height: 280px;
      border: 1px solid var(--border-light);
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-number {
      font-size: 60px;
      font-weight: 800;
      color: rgba(255,107,74,0.2);
      line-height: 1;
      margin-bottom: 10px;
    }
    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
    }

    /* Success Cases */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 20px;
    }
    .case-card {
      background: #FAFAFA;
      padding: 24px;
      border-radius: var(--radius-card);
      border: 1px solid transparent;
      transition: border var(--transition-smooth);
    }
    .case-card:hover {
      border-color: var(--primary);
    }
    .case-logo {
      width: 48px;
      height: 48px;
      background: #e5e7eb;
      border-radius: 50%;
      margin-bottom: 16px;
    }
    .case-number {
      font-size: 28px;
      font-weight: 700;
      color: var(--accent-green);
    }
    .case-quote {
      font-style: italic;
      color: var(--gray-text);
      font-size: 14px;
      margin-top: 8px;
    }
    @media (max-width: 1024px) {
      .cases-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }
    @media (max-width: 500px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--gray-text);
      font-size: 16px;
      border-left: 3px solid var(--primary);
      padding-left: 16px;
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-top: 12px;
      margin-top: 8px;
    }

    /* CTA Banner */
    .cta-banner {
      background-color: var(--primary);
      padding: 80px 0;
      text-align: center;
      color: white;
      border-radius: 0;
      position: relative;
      overflow: hidden;
    }
    .cta-banner::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(circle, rgba(255,255,255,0.15) 1px, transparent 1px);
      background-size: 24px 24px;
    }
    .cta-banner h2 {
      font-size: 36px;
      font-weight: 700;
      position: relative;
    }
    .cta-banner p {
      font-size: 18px;
      opacity: 0.9;
      margin: 16px 0 32px;
      position: relative;
    }

    /* Footer */
    .site-footer {
      background: var(--deep-bg);
      color: white;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-col h4 {
      margin-bottom: 16px;
      font-size: 16px;
    }
    .footer-col a {
      color: #d1d5db;
      display: block;
      margin-bottom: 10px;
      font-size: 14px;
    }
    .footer-bottom {
      text-align: center;
      color: #9ca3af;
      font-size: 13px;
      border-top: 1px solid #374151;
      padding-top: 24px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }