/* roulang page: index */
:root {
      --primary: #1A1A1A;
      --accent: #00E676;
      --accent-glow: rgba(0, 230, 118, 0.4);
      --bg-light: #FAFAFA;
      --bg-subtle: #F0F2F0;
      --text-primary: #1A1A1A;
      --text-secondary: #5F6B6B;
      --white: #FFFFFF;
      --border-light: rgba(0,0,0,0.05);
      --shadow-card: 0px 10px 30px -10px rgba(0,0,0,0.05);
      --shadow-hover: 0px 20px 40px -10px rgba(0,230,118,0.15);
      --radius-lg: 16px;
      --radius-pill: 50px;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.3s ease;
      --spacing-xs: 8px;
      --spacing-sm: 16px;
      --spacing-md: 24px;
      --spacing-lg: 32px;
      --spacing-xl: 48px;
      --spacing-2xl: 80px;
      --spacing-3xl: 120px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 var(--spacing-lg);
    }

    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.5px;
      margin-bottom: var(--spacing-sm);
    }

    h1 {
      font-size: 56px;
      font-weight: 900;
      letter-spacing: -1.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 40px;
      font-weight: 700;
      letter-spacing: -1px;
      margin-bottom: var(--spacing-sm);
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
    }

    p {
      color: var(--text-secondary);
      font-weight: 400;
      line-height: 1.75;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    img {
      max-width: 100%;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      display: block;
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      font-weight: 600;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border: none;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--border-light);
      transition: var(--transition);
    }

    .header.scrolled {
      background: var(--white);
      box-shadow: 0 4px 20px rgba(0,0,0,0.02);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 var(--spacing-lg);
      max-width: 1280px;
      margin: 0 auto;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
    }

    .logo i {
      font-size: 1.8rem;
      color: var(--accent);
    }

    .nav-links {
      display: flex;
      gap: var(--spacing-lg);
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text-primary);
      position: relative;
      padding: 8px 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: var(--transition);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1px solid var(--primary);
      border-radius: var(--radius-pill);
      padding: 10px 24px;
    }

    .btn-outline:hover {
      border-color: var(--accent);
      color: var(--accent);
      background: rgba(0,230,118,0.05);
    }

    .btn-primary {
      background: var(--primary);
      color: var(--white);
      border-radius: var(--radius-pill);
      padding: 14px 32px;
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }

    .btn-primary:hover {
      background: var(--accent);
      color: var(--primary);
      box-shadow: 0 0 20px var(--accent-glow);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
    }

    .hamburger span {
      width: 25px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition);
    }

    /* 首屏 */
    .hero {
      padding: 160px 0 100px;
      display: flex;
      align-items: center;
      gap: 60px;
      background: var(--bg-light);
    }

    .hero-content {
      flex: 1;
    }

    .hero-content h1 {
      margin-bottom: var(--spacing-md);
    }

    .hero-content .highlight {
      color: var(--accent);
    }

    .hero-content p {
      font-size: 1.2rem;
      margin-bottom: var(--spacing-xl);
      max-width: 480px;
    }

    .hero-buttons {
      display: flex;
      gap: var(--spacing-sm);
    }

    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 400px;
      border-radius: var(--radius-lg);
      box-shadow: 0 30px 50px rgba(0,0,0,0.1);
    }

    /* 通用板块 */
    section {
      padding: var(--spacing-3xl) 0;
    }

    .section-header {
      text-align: center;
      margin-bottom: var(--spacing-2xl);
    }

    .bg-subtle {
      background: var(--bg-subtle);
    }

    .bg-dark {
      background: var(--primary);
      color: var(--white);
    }

    /* 服务卡片 - 数字水印风格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--spacing-lg);
    }

    .service-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: var(--spacing-xl);
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      gap: var(--spacing-md);
    }

    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }

    .watermark {
      font-size: 5rem;
      font-weight: 900;
      color: rgba(0,0,0,0.03);
      position: absolute;
      right: 20px;
      bottom: 10px;
      line-height: 1;
      transition: var(--transition);
    }

    .service-card:hover .watermark {
      color: var(--accent);
      opacity: 0.2;
    }

    .service-icon {
      font-size: 2rem;
      color: var(--accent);
      margin-top: 8px;
    }

    .service-text h3 {
      margin-bottom: 8px;
    }

    /* 数据优势 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: var(--spacing-lg);
      text-align: center;
    }

    .stat-item {
      background: var(--white);
      padding: var(--spacing-xl);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }

    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--primary);
    }

    .stat-unit {
      color: var(--accent);
      font-weight: 700;
      margin-left: 4px;
    }

    /* 案例网格 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--spacing-lg);
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      position: relative;
    }

    .case-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }

    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }

    .case-info {
      padding: var(--spacing-md);
    }

    .case-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0,230,118,0.9);
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      transition: var(--transition);
      color: var(--primary);
      font-weight: 700;
      font-size: 1.2rem;
    }

    .case-card:hover .case-overlay {
      opacity: 1;
    }

    /* 时间轴流程 */
    .timeline {
      position: relative;
      max-width: 900px;
      margin: 0 auto;
    }

    .timeline::before {
      content: '';
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      width: 2px;
      height: 100%;
      background: #E0E0E0;
      top: 0;
    }

    .timeline-item {
      display: flex;
      align-items: center;
      margin-bottom: var(--spacing-xl);
      position: relative;
    }

    .timeline-item:nth-child(odd) {
      flex-direction: row;
    }

    .timeline-item:nth-child(even) {
      flex-direction: row-reverse;
    }

    .timeline-content {
      width: 45%;
      background: var(--white);
      padding: var(--spacing-lg);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }

    .timeline-dot {
      width: 20px;
      height: 20px;
      background: var(--white);
      border: 3px solid #E0E0E0;
      border-radius: 50%;
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      z-index: 2;
      transition: var(--transition);
    }

    .timeline-item:hover .timeline-dot {
      background: var(--accent);
      border-color: var(--accent);
      box-shadow: 0 0 15px var(--accent-glow);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      margin-bottom: var(--spacing-sm);
      overflow: hidden;
    }

    .faq-question {
      padding: var(--spacing-md) var(--spacing-lg);
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: var(--white);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease;
      background: var(--bg-subtle);
      padding: 0 var(--spacing-lg);
      color: var(--text-secondary);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: var(--spacing-md) var(--spacing-lg);
    }

    .faq-item.active {
      border-color: var(--accent);
    }

    /* CTA */
    .cta-box {
      text-align: center;
      padding: var(--spacing-2xl) 0;
    }

    .cta-box h2 {
      color: var(--white);
      margin-bottom: var(--spacing-sm);
    }

    .cta-form {
      display: flex;
      max-width: 500px;
      margin: var(--spacing-xl) auto 0;
      gap: 10px;
    }

    .cta-input {
      flex: 1;
      background: transparent;
      border: 1px solid rgba(255,255,255,0.3);
      border-radius: var(--radius-pill);
      padding: 12px 20px;
      color: var(--white);
      font-size: 1rem;
    }

    .cta-input::placeholder {
      color: rgba(255,255,255,0.6);
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: var(--spacing-xl);
      padding: var(--spacing-2xl) 0;
    }

    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.1);
      padding: var(--spacing-md) 0;
      text-align: center;
      color: #9E9E9E;
    }

    @media (max-width: 1024px) {
      .services-grid, .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero {
        flex-direction: column;
      }
      h1 {
        font-size: 44px;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 72px;
        right: 0;
        width: 70%;
        height: 100vh;
        background: var(--bg-light);
        flex-direction: column;
        padding: var(--spacing-xl);
        box-shadow: -10px 0 30px rgba(0,0,0,0.05);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .services-grid, .cases-grid, .stats-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .timeline::before {
        left: 20px;
      }
      .timeline-item, .timeline-item:nth-child(even) {
        flex-direction: column;
        align-items: flex-start;
      }
      .timeline-content {
        width: 85%;
        margin-left: 40px;
      }
      .timeline-dot {
        left: 20px;
      }
      h1 {
        font-size: 36px;
      }
      h2 {
        font-size: 32px;
      }
      .hero {
        padding: 120px 0 60px;
      }
    }

    @media (max-width: 520px) {
      .hero-buttons {
        flex-direction: column;
      }
      .cta-form {
        flex-direction: column;
      }
    }