/* roulang page: index */
:root {
      --primary-blue: #1A5F7A;
      --accent-gold: #D4A843;
      --bg-light: #F8F9FA;
      --card-white: #FFFFFF;
      --text-dark: #2C3E50;
      --text-muted: #6B7280;
      --cta-orange: #E76F51;
      --deep-footer: #1E2A38;
      --border-light: #E5E7EB;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --transition: 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Noto Sans SC', 'Inter', sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border: none;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.3s ease;
      outline: none;
    }
    button:focus-visible, .btn:focus-visible {
      outline: 2px solid var(--primary-blue);
      outline-offset: 2px;
    }
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    h1 { font-size: 42px; font-weight: 800; }
    h2 { font-size: 32px; }
    h3 { font-size: 24px; font-weight: 600; }
    .section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      h1 { font-size: 32px; }
      h2 { font-size: 28px; }
      h3 { font-size: 22px; }
      .section { padding: 60px 0; }
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      z-index: 1000;
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
      transition: box-shadow 0.3s;
    }
    .header.scrolled {
      box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 800;
      font-size: 20px;
      color: var(--primary-blue);
    }
    .logo-icon {
      background: linear-gradient(135deg, var(--primary-blue), #0d3b4c);
      color: white;
      width: 36px;
      height: 36px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 16px;
      letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-dark);
      position: relative;
      padding: 8px 0;
      font-size: 15px;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--accent-gold);
      transition: 0.3s ease;
      transform: translateX(-50%);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--accent-gold);
      color: white;
      padding: 12px 24px;
      font-weight: 700;
    }
    .btn-primary:hover {
      background: #b58d2f;
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--primary-blue);
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        gap: 20px;
        padding: 30px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        transform: translateX(-100%);
        transition: 0.3s ease;
        z-index: 999;
      }
      .nav-links.active {
        transform: translateX(0);
      }
      .mobile-menu-btn {
        display: block;
      }
    }

    /* Hero */
    .hero {
      height: 100vh;
      min-height: 650px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      color: white;
      margin-top: 72px;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(to top, rgba(26,95,122,0.85) 0%, rgba(0,0,0,0.3) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .hero h1 {
      color: white;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.9);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-outline-light {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 12px 28px;
    }
    .btn-outline-light:hover {
      background: white;
      color: var(--primary-blue);
    }
    .floating-stat {
      position: absolute;
      right: 40px;
      bottom: 80px;
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(10px);
      padding: 20px 30px;
      border-radius: 16px;
      color: white;
      font-weight: 700;
      font-size: 18px;
      border: 1px solid rgba(255,255,255,0.2);
    }
    @media (max-width: 768px) {
      .hero {
        height: auto;
        padding: 100px 0 80px;
      }
      .floating-stat {
        position: static;
        margin-top: 30px;
        width: fit-content;
      }
    }

    /* 服务卡片 - 非对称 */
    .services-grid {
      display: flex;
      gap: 24px;
      align-items: flex-start;
      margin-top: 50px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      flex: 1;
      transition: var(--transition);
      border: 1px solid var(--border-light);
      display: flex;
      flex-direction: column;
    }
    .service-card.center {
      background: var(--primary-blue);
      color: white;
      transform: translateY(-20px);
      box-shadow: var(--shadow-hover);
      border: none;
    }
    .service-card.center .service-icon {
      color: var(--accent-gold);
    }
    .service-icon {
      font-size: 48px;
      color: var(--accent-gold);
      margin-bottom: 20px;
    }
    .service-card h3 {
      margin-bottom: 12px;
    }
    .service-desc {
      color: var(--text-muted);
      font-size: 15px;
      margin-bottom: 20px;
      flex: 1;
    }
    .center .service-desc {
      color: rgba(255,255,255,0.85);
    }
    .arrow-link {
      font-weight: 600;
      color: var(--primary-blue);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .center .arrow-link {
      color: var(--accent-gold);
    }
    @media (max-width: 768px) {
      .services-grid {
        flex-direction: column;
      }
      .service-card.center {
        transform: none;
      }
    }

    /* 优势数据 */
    .advantages {
      background: #EDF2F7;
    }
    .stats-grid {
      display: flex;
      justify-content: space-between;
      text-align: center;
    }
    .stat-item h3 {
      font-size: 48px;
      font-family: 'Inter', sans-serif;
      color: var(--primary-blue);
      font-weight: 700;
    }
    .stat-unit {
      font-size: 18px;
      color: var(--text-muted);
    }
    @media (max-width: 768px) {
      .stats-grid {
        flex-wrap: wrap;
        gap: 30px;
        justify-content: center;
      }
      .stat-item {
        width: 45%;
      }
    }

    /* 案例网格 2x3 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 50px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 200px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.05);
    }
    .case-info {
      padding: 20px;
    }
    .case-tag {
      background: var(--accent-gold);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 10px;
    }
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 480px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-top: 50px;
    }
    .step {
      text-align: center;
      flex: 1;
    }
    .step-circle {
      width: 60px;
      height: 60px;
      background: var(--primary-blue);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 24px;
      margin: 0 auto 15px;
    }
    .step-arrow {
      color: var(--accent-gold);
      font-size: 28px;
      margin: 0 10px;
    }
    @media (max-width: 768px) {
      .process-steps {
        flex-direction: column;
        gap: 30px;
      }
      .step-arrow {
        transform: rotate(90deg);
      }
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-size: 18px;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--text-muted);
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-icon {
      color: var(--accent-gold);
      font-weight: bold;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(to right, var(--primary-blue), var(--accent-gold));
      color: white;
      text-align: center;
    }
    .cta-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      margin-top: 30px;
      flex-wrap: wrap;
    }
    .btn-white {
      background: white;
      color: var(--primary-blue);
      padding: 14px 32px;
    }
    .btn-white-border {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 14px 32px;
    }

    /* Footer */
    .footer {
      background: var(--deep-footer);
      color: #ccc;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer h4 {
      color: var(--accent-gold);
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }