/* roulang page: index */
:root {
      --primary: #1A6DF5;
      --primary-hover: #1250C4;
      --accent: #FF5E3A;
      --accent-hover: #E04A2A;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --bg: #F5F6FA;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E8ECF1;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-pill: 24px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: 200ms ease;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    img {
      max-width: 100%;
      display: block;
      height: auto;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      z-index: 100;
      height: 64px;
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.25s ease;
    }

    header.scrolled {
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      border-bottom-color: var(--border-light);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo {
      font-weight: 700;
      font-size: 20px;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
      white-space: nowrap;
    }
    .logo i {
      font-size: 24px;
      color: var(--accent);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: all var(--transition);
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: transparent;
      border: none;
      width: 28px;
      padding: 4px 0;
    }
    .hamburger span {
      display: block;
      height: 2px;
      background: var(--text);
      border-radius: 2px;
      transition: all 0.3s;
    }

    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        background: var(--white);
        flex-direction: column;
        gap: 0;
        padding: 16px 0;
        box-shadow: var(--shadow-md);
        transform: translateY(-120%);
        opacity: 0;
        transition: all 0.3s ease;
        pointer-events: none;
      }
      .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }
      .nav-menu li {
        width: 100%;
        text-align: center;
        padding: 12px 0;
      }
      .hamburger {
        display: flex;
      }
    }

    /* hero */
    .hero {
      padding: 160px 0 100px;
      background: linear-gradient(135deg, #ffffff 0%, #f0f4ff 100%);
      position: relative;
      overflow: hidden;
    }

    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-text {
      flex: 1;
    }
    .hero h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: var(--text);
    }
    .hero .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      background: #d9e2f0;
      min-height: 320px;
    }
    .hero-visual img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      filter: brightness(0.95);
    }

    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
      }
      .hero h1 {
        font-size: 32px;
      }
      .hero-visual {
        width: 100%;
        min-height: 240px;
      }
    }

    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      font-size: 16px;
      transition: background var(--transition), transform 0.2s;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      font-size: 16px;
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background: #EEF3FF;
    }

    .btn-accent {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 36px;
      border-radius: var(--radius-pill);
      font-weight: 700;
      font-size: 18px;
      transition: background var(--transition), transform 0.2s;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }

    section {
      padding: 80px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    .section-title {
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 16px;
      text-align: center;
      color: var(--text);
    }
    .section-sub {
      text-align: center;
      color: var(--text-secondary);
      margin-bottom: 48px;
      font-size: 16px;
    }

    /* 核心优势 非对称 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 40px;
    }
    .advantage-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
    }
    .advantage-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .advantage-card:nth-child(3) {
      grid-column: span 2;
      justify-self: center;
      width: 50%;
    }
    .adv-icon {
      width: 56px;
      height: 56px;
      background: #EEF3FF;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 24px;
    }
    .adv-title {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .adv-desc {
      color: var(--text-secondary);
    }

    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .advantage-card:nth-child(3) {
        grid-column: span 1;
        width: 100%;
      }
    }

    /* 服务卡片横向滚动 */
    .services-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding: 8px 0 24px;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
    }
    .services-scroll::-webkit-scrollbar {
      display: none;
    }
    .service-card {
      flex: 0 0 280px;
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      scroll-snap-align: start;
      transition: all 0.25s;
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-img {
      height: 140px;
      background: #eef2f9;
      border-radius: 12px 12px 0 0;
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-info {
      padding: 20px;
    }
    .service-info h3 {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 6px;
    }

    /* 场景交替 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 60px;
    }
    .scene-row.reverse {
      flex-direction: row-reverse;
    }
    .scene-text {
      flex: 1;
    }
    .scene-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      background: #eef2f9;
      min-height: 260px;
    }
    .scene-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    @media (max-width: 768px) {
      .scene-row, .scene-row.reverse {
        flex-direction: column;
      }
    }

    /* 数据 */
    .stats {
      display: flex;
      justify-content: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
    }
    .stat-label {
      color: var(--text-secondary);
    }

    /* FAQ */
    .faq-list {
      max-width: 780px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      padding: 16px 20px;
      cursor: pointer;
      transition: background 0.2s;
    }
    .faq-q {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 15px;
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA */
    .cta-dark {
      background: #0F3B8C;
      color: white;
      text-align: center;
      padding: 80px 24px;
      border-radius: 0;
    }
    .cta-dark h2 {
      font-size: 32px;
      margin-bottom: 16px;
    }

    footer {
      background: var(--white);
      padding: 48px 0 24px;
      color: var(--text-secondary);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      margin-bottom: 32px;
    }
    .footer-col h4 {
      color: var(--text);
      margin-bottom: 12px;
    }
    .copyright {
      text-align: center;
      border-top: 1px solid var(--border-light);
      padding-top: 20px;
      font-size: 14px;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .stats {
        gap: 24px;
      }
    }