/* roulang page: index */
:root {
      --primary: #1A56DB;
      --primary-hover: #1538A0;
      --primary-light: #EBF0FA;
      --accent: #F59E0B;
      --accent-hover: #D97706;
      --dark-title: #0F172A;
      --body-text: #334155;
      --muted: #64748B;
      --bg: #F8FAFC;
      --white: #FFFFFF;
      --border-light: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 20px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1280px;
      --nav-height: 64px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--body-text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.3s ease;
    }
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }
    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      z-index: 50;
      display: flex;
      align-items: center;
      padding: 0 20px;
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
    }
    .logo {
      font-weight: 700;
      font-size: 20px;
      color: var(--primary);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--body-text);
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      white-space: nowrap;
    }
    .nav-cta:hover {
      background: var(--primary-hover);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--dark-title);
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      background: white;
      flex-direction: column;
      padding: 24px 20px;
      gap: 20px;
      border-bottom: 1px solid var(--border-light);
      z-index: 49;
      box-shadow: var(--shadow-sm);
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
    }
    .mobile-menu .nav-cta {
      width: 100%;
      text-align: center;
      padding: 14px;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu.active {
        display: flex;
      }
    }
    /* 区块通用 */
    section {
      padding: 80px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--dark-title);
      margin-bottom: 16px;
      text-align: center;
    }
    @media (max-width: 520px) {
      .section-title {
        font-size: 28px;
      }
    }
    .section-sub {
      text-align: center;
      color: var(--muted);
      margin-bottom: 48px;
      font-size: 18px;
    }
    /* Hero */
    #hero {
      padding-top: calc(var(--nav-height) + 40px);
      background: var(--white);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 44px;
      font-weight: 700;
      color: var(--dark-title);
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-text .sub {
      font-size: 18px;
      color: var(--muted);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 17px;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-1px);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 17px;
      background: transparent;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 360px;
      border-radius: 16px;
      box-shadow: var(--shadow-sm);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column-reverse;
      }
      .hero-image {
        width: 100%;
        min-height: 260px;
      }
      .hero-text h1 {
        font-size: 36px;
      }
    }
    /* 卡片基础 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 28px;
      transition: all 0.3s ease;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    /* Features */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-icon {
      font-size: 40px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .feature-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 10px;
      color: var(--dark-title);
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }
    /* Products 左右交替 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .product-row.reverse {
      flex-direction: row-reverse;
    }
    .product-text {
      flex: 1;
    }
    .product-text h2 {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--dark-title);
    }
    .product-list {
      list-style: none;
      margin: 20px 0;
    }
    .product-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 12px;
      font-weight: 500;
    }
    .product-list i {
      color: var(--primary);
    }
    .product-image {
      flex: 1;
      background: #f1f5f9;
      border-radius: var(--radius-card);
      min-height: 280px;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
    }
    .product-image img {
      object-fit: cover;
      width: 100%;
      height: 100%;
    }
    @media (max-width: 768px) {
      .product-row, .product-row.reverse {
        flex-direction: column;
      }
      .product-image {
        width: 100%;
      }
    }
    /* Scenarios */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scenario-img {
      background: #e9eef3;
      height: 180px;
      border-radius: 12px 12px 0 0;
      overflow: hidden;
    }
    .scenario-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    @media (max-width: 768px) {
      .scenarios-grid {
        grid-template-columns: 1fr;
      }
    }
    /* Cases */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      border-left: 4px solid var(--primary);
      padding-left: 20px;
    }
    .quote {
      font-style: italic;
      font-size: 15px;
      margin-bottom: 16px;
      color: var(--body-text);
    }
    .data-highlight {
      font-weight: 700;
      color: var(--primary);
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }
    /* Pricing */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: start;
    }
    .pricing-card {
      position: relative;
      border: 1px solid var(--border-light);
    }
    .pricing-card.featured {
      border: 2px solid var(--accent);
      transform: scale(1.02);
    }
    .badge {
      position: absolute;
      top: -12px;
      right: 20px;
      background: var(--accent);
      color: white;
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
    }
    .price {
      font-size: 36px;
      font-weight: 700;
      color: var(--dark-title);
      margin: 16px 0;
    }
    .pricing-features {
      list-style: none;
      margin: 20px 0;
    }
    .pricing-features li {
      margin-bottom: 10px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    @media (max-width: 768px) {
      .pricing-grid {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      font-size: 18px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--dark-title);
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--body-text);
      padding-right: 20px;
    }
    .faq-answer.open {
      max-height: 200px;
      margin-top: 12px;
    }
    /* CTA */
    #cta {
      background: linear-gradient(135deg, #1A56DB 0%, #4F7FE8 100%);
      color: white;
      text-align: center;
      padding: 80px 20px;
    }
    #cta h2 {
      font-size: 34px;
      font-weight: 700;
    }
    .cta-btn {
      background: var(--accent);
      color: #0F172A;
      font-weight: 700;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-size: 18px;
      margin-top: 24px;
      display: inline-block;
    }
    .cta-btn:hover {
      background: #FBBF24;
    }
    /* Footer */
    #footer {
      background: #0F172A;
      color: #CBD5E1;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      margin-bottom: 32px;
    }
    .footer-logo {
      font-weight: 700;
      font-size: 20px;
      color: white;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    .copyright {
      text-align: center;
      font-size: 14px;
      color: #94A3B8;
    }