/* roulang page: index */
:root {
      --primary: #1A3C6D;
      --primary-deep: #0F2647;
      --accent: #E8492A;
      --accent-hover: #C63A1F;
      --bg: #F8FAFC;
      --bg-light: #EEF2F6;
      --text: #1E293B;
      --text-light: #64748B;
      --white: #FFFFFF;
      --success: #10B981;
      --border: #E2E8F0;
      --radius: 12px;
      --radius-sm: 8px;
      --shadow: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.10);
      --transition: 0.2s ease;
      --container: 1200px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
      background: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      padding-top: var(--nav-height);
    }
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    h1, h2, h3, h4 {
      font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--white);
      box-shadow: 0 1px 0 var(--border);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--accent);
      font-size: 28px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--primary);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-nav {
      background: var(--accent);
      color: var(--white) !important;
      padding: 10px 24px !important;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: background var(--transition);
    }
    .btn-nav:hover {
      background: var(--accent-hover);
    }
    .btn-nav::after {
      display: none;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      background: var(--white);
      padding: 32px 24px;
      flex-direction: column;
      gap: 24px;
      box-shadow: 0 10px 25px rgba(0,0,0,0.08);
      z-index: 999;
    }
    .mobile-menu a {
      font-size: 20px;
      font-weight: 500;
      color: var(--primary);
      padding: 12px 0;
      border-bottom: 1px solid var(--border);
      display: block;
    }

    /* 板块 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }
    .section-title h2 {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .section-title p {
      color: var(--text-light);
      font-size: 18px;
      max-width: 600px;
      margin: 0 auto;
    }
    .bg-light {
      background: var(--bg-light);
    }

    /* Hero */
    .hero {
      min-height: 600px;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #1A3C6D 0%, #0F2647 100%);
      position: relative;
      overflow: hidden;
      color: var(--white);
    }
    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      right: 0;
      width: 50%;
      height: 100%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25;
      mask-image: linear-gradient(to left, rgba(0,0,0,0.7), transparent);
      -webkit-mask-image: linear-gradient(to left, rgba(0,0,0,0.7), transparent);
    }
    .hero .container {
      position: relative;
      z-index: 2;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.25;
      margin-bottom: 20px;
    }
    .hero-content p {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      transition: all var(--transition);
      cursor: pointer;
      text-align: center;
      border: 2px solid transparent;
    }
    .btn-primary {
      background: var(--accent);
      color: var(--white);
      border-color: var(--accent);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      border-color: var(--accent-hover);
    }
    .btn-outline {
      background: transparent;
      color: var(--white);
      border-color: var(--white);
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
    }
    .hero-visual img {
      border-radius: var(--radius);
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      width: 100%;
    }

    /* 核心优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .advantage-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      text-align: center;
      transition: transform var(--transition), box-shadow var(--transition);
    }
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .advantage-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: 20px;
    }
    .advantage-card h3 {
      font-size: 20px;
      margin-bottom: 8px;
      color: var(--primary);
    }

    /* 服务 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      overflow: hidden;
      transition: all var(--transition);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .service-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .service-body {
      padding: 24px 28px 28px;
    }
    .service-body h3 {
      font-size: 22px;
      margin-bottom: 8px;
    }

    /* 数据展示 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-light);
      font-size: 16px;
      margin-top: 8px;
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      overflow: hidden;
    }
    .case-card img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
    }
    .case-body {
      padding: 20px 24px 24px;
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
    }
    .steps::before {
      content: '';
      position: absolute;
      top: 32px;
      left: 10%;
      width: 80%;
      height: 2px;
      background: repeating-linear-gradient(90deg, var(--border) 0 8px, transparent 8px 16px);
      z-index: 0;
    }
    .step {
      text-align: center;
      position: relative;
      z-index: 1;
      flex: 1;
    }
    .step-circle {
      width: 64px;
      height: 64px;
      background: var(--accent);
      color: var(--white);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      font-weight: 700;
      margin: 0 auto 16px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border-radius: var(--radius);
      margin-bottom: 12px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: var(--white);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: #F1F5F9;
    }
    .faq-answer p {
      padding: 0 24px 16px;
      color: var(--text);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
    }

    /* CTA 联系 */
    .cta-contact {
      background: var(--primary);
      color: var(--white);
    }
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: start;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px;
      border-radius: var(--radius-sm);
      border: none;
      margin-bottom: 16px;
      background: var(--white);
    }
    .contact-info i {
      color: var(--accent);
      margin-right: 12px;
    }
    .btn-submit {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      cursor: pointer;
      width: 100%;
    }

    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: #CBD5E1;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .advantages-grid, .stats-grid { grid-template-columns: repeat(2, 1fr); }
      .services-grid, .cases-grid { grid-template-columns: repeat(2, 1fr); }
      .hero .container { grid-template-columns: 1fr; }
      .hero-visual { display: none; }
      .contact-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .advantages-grid, .services-grid, .cases-grid, .stats-grid, .footer-grid { grid-template-columns: 1fr; }
      .steps { flex-direction: column; gap: 24px; }
      .steps::before { display: none; }
      .section { padding: 60px 0; }
      .hero-content h1 { font-size: 34px; }
    }