/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-dark: #144DB0;
      --accent: #F07B3F;
      --accent-dark: #d9682e;
      --bg: #FAFBFD;
      --white: #FFFFFF;
      --text: #1E2A38;
      --text-light: #5A6B7F;
      --border: #E5E9F0;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --radius: 12px;
      --radius-btn: 8px;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-num: "Inter", "Segoe UI", sans-serif;
      --nav-height: 64px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-cn);
      background: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-cn);
      font-weight: 700;
      margin-top: 0;
      color: var(--text);
    }
    h1 { font-size: clamp(2.2rem, 5vw, 2.6rem); line-height: 1.3; }
    h2 { font-size: clamp(1.8rem, 4vw, 2.2rem); margin-bottom: 1rem; }
    h3 { font-size: 1.25rem; font-weight: 600; }
    .section-title {
      text-align: center;
      margin-bottom: 2.5rem;
    }
    .section-subtitle {
      color: var(--text-light);
      text-align: center;
      max-width: 680px;
      margin: 0 auto 2rem;
      font-size: 1.1rem;
    }
    a {
      color: var(--primary);
      text-decoration: none;
      transition: color 0.2s;
    }
    a:hover {
      color: var(--primary-dark);
      text-decoration: underline;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    /* 导航 */
    .site-header {
      background: var(--white);
      border-bottom: 1px solid var(--border);
      position: sticky;
      top: 0;
      z-index: 50;
      height: var(--nav-height);
      display: flex;
      align-items: center;
      transition: box-shadow 0.2s;
    }
    .site-header.scrolled {
      box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .logo i {
      font-size: 1.8rem;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      color: var(--text);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.25rem 0;
      border-bottom: 3px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
      text-decoration: none;
    }
    .btn {
      display: inline-block;
      font-weight: 600;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      transition: all 0.25s ease;
      cursor: pointer;
      border: none;
      font-size: 0.95rem;
      font-family: var(--font-cn);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      color: white;
      text-decoration: none;
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      text-decoration: none;
    }
    .btn-accent {
      background: var(--accent);
      color: white;
    }
    .btn-accent:hover {
      background: var(--accent-dark);
      color: white;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.6rem;
      color: var(--text);
    }
    /* Hero */
    .hero {
      padding: 3rem 0 4rem;
      background: linear-gradient(135deg, #f8faff 0%, #f0f5ff 100%);
    }
    .hero .grid-x {
      align-items: center;
    }
    .hero-content h1 {
      margin-bottom: 1.2rem;
    }
    .hero-content p {
      font-size: 1.15rem;
      color: var(--text-light);
      margin-bottom: 2rem;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-image {
      text-align: right;
    }
    .hero-image img {
      border-radius: 20px;
      box-shadow: 0 20px 35px rgba(26,95,220,0.1);
      transform: rotate(1deg);
      border: 2px solid rgba(240,123,63,0.2);
    }
    /* 板块通用 */
    section {
      padding: 4.5rem 0;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      padding: 2rem 1.8rem;
      transition: all 0.3s ease;
      height: 100%;
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      border-radius: 16px;
      background: rgba(26,95,220,0.08);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.8rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }
    .accent-icon {
      background: rgba(240,123,63,0.1);
      color: var(--accent);
    }
    /* Features */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 2rem;
    }
    /* Services 卡片带图 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 2rem;
    }
    .service-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 12px;
      margin-bottom: 1.2rem;
    }
    .service-card .learn-more {
      margin-top: auto;
      font-weight: 600;
      color: var(--primary);
      display: inline-flex;
      align-items: center;
      gap: 0.3rem;
    }
    /* 场景图文交错 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 3rem;
      background: var(--white);
      border-radius: 20px;
      padding: 1.5rem;
      box-shadow: var(--shadow-sm);
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-text {
      flex: 1;
      padding: 1rem;
    }
    .scenario-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
    }
    .scenario-img img {
      border-radius: 16px;
      height: 240px;
      object-fit: cover;
      width: 100%;
    }
    /* 案例数字墙 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 2rem;
      text-align: center;
    }
    .stat-item {
      background: var(--white);
      padding: 2rem 1rem;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
    }
    .stat-number {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary);
      font-family: var(--font-num);
    }
    /* FAQ */
    .accordion-item {
      background: var(--white);
      border-radius: 12px;
      margin-bottom: 1rem;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
      overflow: hidden;
    }
    .accordion-btn {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      padding: 1.2rem 1.8rem;
      font-size: 1.1rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text);
      transition: background 0.2s;
    }
    .accordion-btn i {
      transition: transform 0.3s;
      color: var(--primary);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #f9fbfd;
      padding: 0 1.8rem;
    }
    .accordion-content p {
      padding: 1rem 0 1.5rem;
      margin: 0;
      color: var(--text-light);
    }
    .accordion-item.active .accordion-content {
      max-height: 200px;
    }
    .accordion-item.active .accordion-btn i {
      transform: rotate(45deg);
    }
    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 4rem 1.5rem;
      border-radius: 24px;
      margin: 0 1rem;
    }
    .cta-banner h2 {
      color: white;
      margin-bottom: 1rem;
    }
    /* 页脚 */
    .site-footer {
      background: #1E2A38;
      color: #B0BEC5;
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 2rem;
    }
    .footer-grid h4 {
      color: white;
      margin-bottom: 1.2rem;
      font-size: 1rem;
    }
    .footer-grid a {
      color: #B0BEC5;
      display: block;
      margin-bottom: 0.5rem;
      font-size: 0.9rem;
    }
    .footer-grid a:hover {
      color: white;
    }
    .copyright {
      border-top: 1px solid #344050;
      margin-top: 2.5rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.85rem;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .features-grid, .services-grid {
        grid-template-columns: repeat(2,1fr);
      }
      .stats-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        padding: 1.5rem;
        box-shadow: 0 15px 25px rgba(0,0,0,0.08);
        gap: 1rem;
      }
      .nav-links.open {
        display: flex;
      }
      .mobile-toggle {
        display: block;
      }
      .hero .grid-x {
        flex-direction: column;
        text-align: center;
      }
      .hero-image {
        text-align: center;
        margin-top: 2rem;
      }
      .features-grid, .services-grid {
        grid-template-columns: 1fr;
      }
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
      .stats-grid {
        grid-template-columns: 1fr 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 520px) {
      .stats-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-buttons {
        flex-direction: column;
        align-items: center;
      }
    }