/* roulang page: index */
:root {
      --primary: #0A2647;
      --primary-soft: #143A5E;
      --accent: #F6AE2D;
      --accent-glow: #E89C1A;
      --bg: #FFFFFF;
      --bg-soft: #F8FAFC;
      --text-heading: #1E293B;
      --text-body: #475569;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --border-input: #CBD5E1;
      --danger: #E11D48;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.12);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 10px;
      --transition: 0.3s ease;
      --container: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
    }
    h1, h2, h3, h4 {
      color: var(--text-heading);
      font-weight: 700;
      line-height: 1.3;
    }
    h1 { font-size: 48px; font-weight: 900; letter-spacing: -0.5px; }
    h2 { font-size: 36px; font-weight: 800; }
    h3 { font-size: 24px; font-weight: 700; }
    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      h3 { font-size: 20px; }
      .container { padding: 0 16px; }
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: white;
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .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(--text-muted);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      box-shadow: 0 4px 10px rgba(10,38,71,0.15);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background: var(--accent);
      color: var(--primary);
      box-shadow: var(--shadow-hover);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .hamburger {
      display: none;
      font-size: 26px;
      background: none;
      border: none;
      color: var(--primary);
    }
    @media (max-width: 1024px) {
      .nav-links { gap: 20px; }
    }
    @media (max-width: 768px) {
      .hamburger { display: block; }
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 32px 24px;
        gap: 24px;
        box-shadow: var(--shadow-md);
        transform: translateY(-150%);
        transition: 0.35s ease;
        opacity: 0;
        pointer-events: none;
      }
      .nav-links.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }
      .nav-links a { font-size: 18px; }
    }
    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: var(--bg);
      display: flex;
      align-items: center;
      gap: 60px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 50%;
    }
    .hero-content h1 {
      margin-bottom: 24px;
    }
    .hero-content p {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
      max-width: 540px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1 1 45%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      min-height: 380px;
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .hero-image::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(10,38,71,0.45) 0%, rgba(246,174,45,0.2) 100%);
      border-radius: 24px;
    }
    @media (max-width: 768px) {
      .hero { flex-direction: column; padding: 100px 0 60px; }
      .hero-image { width: 100%; min-height: 280px; }
    }
    /* 板块通用 */
    .section {
      padding: 100px 0;
    }
    .section-soft {
      background: var(--bg-soft);
    }
    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }
    .section-title h2 {
      margin-bottom: 12px;
    }
    .section-title p {
      color: var(--text-muted);
      font-size: 17px;
    }
    .accent-line {
      width: 60px;
      height: 4px;
      background: var(--accent);
      margin: 16px auto 24px;
      border-radius: 2px;
    }
    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: white;
      border-radius: var(--radius-card);
      padding: 36px 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border-light);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
      border-color: transparent;
    }
    .icon-circle {
      width: 64px;
      height: 64px;
      background: #F0F4FE;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--primary);
      font-size: 28px;
    }
    .card h3 { margin-bottom: 12px; }
    .card p { color: var(--text-body); margin-bottom: 20px; }
    .link-arrow {
      font-weight: 600;
      color: var(--primary);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .link-arrow i { transition: 0.2s; }
    .link-arrow:hover i { transform: translateX(5px); color: var(--accent); }
    /* 数据优势 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 15px;
      margin-top: 8px;
    }
    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      border-radius: var(--radius-card);
      overflow: hidden;
      position: relative;
      background: white;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 220px;
      background-size: cover;
      background-position: center;
      transition: 0.4s ease;
    }
    .case-card:hover .case-img { transform: scale(1.05); }
    .case-info {
      padding: 20px;
      background: white;
      position: relative;
      z-index: 2;
    }
    .case-tag {
      background: var(--accent);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 700;
      display: inline-block;
      margin-bottom: 8px;
    }
    /* 解决方案 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-img {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .solution-img img {
      width: 100%;
      height: auto;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 8px 0;
    }
    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 8px;
      font-size: 18px;
      font-weight: 600;
      color: var(--text-heading);
      cursor: pointer;
      text-align: left;
    }
    .faq-icon {
      font-size: 20px;
      transition: 0.3s;
      color: var(--primary);
    }
    .faq-answer {
      padding: 0 8px 20px;
      color: var(--text-body);
      display: none;
    }
    .faq-item.active .faq-answer { display: block; }
    .faq-item.active .faq-icon i { transform: rotate(45deg); }
    /* 联系表单 */
    .contact-wrapper {
      display: flex;
      gap: 48px;
      align-items: flex-start;
      flex-wrap: wrap;
    }
    .contact-form {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }
    .contact-form input, .contact-form textarea {
      border: 1px solid var(--border-input);
      border-radius: var(--radius-input);
      padding: 14px 18px;
      font-size: 16px;
      width: 100%;
      outline: none;
    }
    .contact-form input:focus, .contact-form textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(10,38,71,0.1);
    }
    .contact-info {
      flex: 0 0 280px;
      background: var(--bg-soft);
      padding: 32px;
      border-radius: var(--radius-card);
    }
    /* 页脚 */
    .footer {
      background: var(--primary);
      color: white;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer a {
      color: #94A3B8;
      font-size: 15px;
      display: block;
      margin-bottom: 10px;
    }
    .footer a:hover { color: white; }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.15);
      padding-top: 24px;
      text-align: center;
      color: #94A3B8;
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .grid-3, .case-grid, .stats-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .section { padding: 60px 0; }
    }