/* roulang page: index */
:root {
      --primary: #2D5BFF;
      --primary-hover: #1A3FCC;
      --bg: #F5F6FA;
      --card-bg: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --dark-bg: #1A1F36;
      --radius-lg: 16px;
      --radius-md: 12px;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04), 0 0 1px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08), 0 0 1px rgba(0,0,0,0.08);
      --success: #00C48C;
      --warning: #FF8A3D;
      --error: #F53B57;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 40px;
    }

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

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

    /* 导航 */
    #header-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,0,0,0.04);
      z-index: 100;
      transition: background 0.3s, box-shadow 0.3s;
    }

    #header-nav.scrolled {
      background: rgba(255, 255, 255, 1);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 40px;
      height: 72px;
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      transition: color 0.2s;
      padding: 4px 0;
    }

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

    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }

    .btn-nav {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: 50px;
      font-size: 15px;
      font-weight: 600;
      transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
      display: inline-block;
    }

    .btn-nav:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(45,91,255,0.2);
    }

    /* 移动端底部导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: white;
      border-top: 1px solid rgba(0,0,0,0.05);
      box-shadow: 0 -4px 12px rgba(0,0,0,0.02);
      z-index: 100;
      padding: 8px 16px 12px;
      justify-content: space-around;
      align-items: center;
    }

    .mobile-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 12px;
      color: var(--text-secondary);
      gap: 4px;
    }

    .mobile-nav a.active {
      color: var(--primary);
    }

    .mobile-nav .center-btn {
      background: var(--primary);
      color: white;
      border-radius: 50px;
      padding: 10px 22px;
      font-weight: 600;
      font-size: 14px;
      box-shadow: 0 4px 12px rgba(45,91,255,0.3);
      margin-top: -16px;
    }

    /* Hero */
    #hero {
      padding: 140px 0 100px;
      background: linear-gradient(180deg, #F5F6FA 0%, #EEF0F5 100%);
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-title {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-primary);
      margin-bottom: 24px;
    }

    .hero-sub {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 40px;
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: 50px;
      font-weight: 600;
      font-size: 16px;
      transition: all 0.2s ease;
      border: none;
      cursor: pointer;
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(45,91,255,0.25);
    }

    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: 50px;
      font-weight: 600;
      font-size: 16px;
      transition: all 0.2s ease;
      cursor: pointer;
    }

    .btn-secondary:hover {
      background: rgba(45,91,255,0.08);
      transform: translateY(-2px);
    }

    .data-dashboard {
      background: var(--dark-bg);
      border-radius: 20px;
      padding: 32px;
      color: white;
      box-shadow: 0 20px 40px rgba(0,0,0,0.1);
      position: relative;
      overflow: hidden;
    }

    .dashboard-metrics {
      display: flex;
      justify-content: space-between;
      margin-bottom: 30px;
    }

    .metric {
      text-align: center;
    }

    .metric-value {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }

    .metric-label {
      font-size: 14px;
      color: #A0A7B8;
    }

    .progress-ring {
      display: flex;
      justify-content: center;
      gap: 30px;
      margin: 20px 0;
    }

    .ring {
      width: 70px;
      height: 70px;
      border-radius: 50%;
      background: conic-gradient(var(--primary) 0% 94.7%, #2a2f45 94.7% 100%);
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .ring span {
      background: var(--dark-bg);
      width: 54px;
      height: 54px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 18px;
    }

    .scan-line {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: linear-gradient(90deg, transparent, var(--primary), transparent);
      opacity: 0.6;
      animation: scan 3s infinite;
    }

    @keyframes scan {
      0% { transform: translateY(0); opacity: 0.4; }
      50% { transform: translateY(-10px); opacity: 0.8; }
      100% { transform: translateY(0); opacity: 0.4; }
    }

    /* 通用板块样式 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 700;
      color: var(--text-primary);
      text-align: center;
      margin-bottom: 16px;
    }

    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--card-bg);
      padding: 32px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .feature-icon {
      width: 48px;
      height: 48px;
      color: var(--primary);
      margin-bottom: 20px;
    }

    .feature-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .feature-card p {
      color: var(--text-secondary);
      font-size: 16px;
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 24px;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .service-img {
      height: 160px;
      background-size: cover;
      background-position: center;
      border-radius: 12px;
      margin-bottom: 20px;
    }

    .service-tags {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      margin-top: 16px;
    }

    .tag {
      background: rgba(45,91,255,0.08);
      color: var(--primary);
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 12px;
      font-weight: 500;
    }

    /* 数据对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: 5fr 2fr 5fr;
      align-items: center;
      gap: 20px;
    }

    .compare-card {
      padding: 32px;
      border-radius: var(--radius-lg);
    }

    .compare-before {
      background: #F0F1F5;
    }

    .compare-after {
      background: white;
      border-left: 4px solid var(--primary);
    }

    .arrow-icon {
      font-size: 40px;
      color: var(--primary);
      text-align: center;
      animation: pulse 1.8s infinite;
    }

    @keyframes pulse {
      0% { transform: scale(1); opacity: 0.7; }
      50% { transform: scale(1.2); opacity: 1; }
      100% { transform: scale(1); opacity: 0.7; }
    }

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

    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 12px;
      padding: 16px 24px;
      cursor: pointer;
      transition: 0.2s;
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 16px;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
      font-size: 16px;
      padding-left: 12px;
      border-left: 3px solid transparent;
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 12px;
      border-left-color: var(--primary);
    }

    /* 表单 */
    #contact {
      background: var(--bg);
    }

    .contact-card {
      background: white;
      max-width: 600px;
      margin: 0 auto;
      padding: 48px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }

    .input-group {
      margin-bottom: 20px;
    }

    .input-group input {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid #D0D5DD;
      border-radius: 12px;
      font-size: 16px;
      transition: 0.2s;
    }

    .input-group input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(45,91,255,0.2);
    }

    .btn-submit {
      width: 100%;
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px;
      border-radius: 12px;
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: 0.2s;
    }

    .btn-submit:hover {
      background: var(--primary-hover);
    }

    /* 页脚 */
    #footer {
      background: var(--dark-bg);
      color: white;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      font-size: 12px;
      color: #A0A7B8;
      text-align: center;
    }

    @media (max-width: 1024px) {
      .container {
        padding: 0 24px;
      }
      .nav-links {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .features-grid,
      .services-grid {
        grid-template-columns: 1fr 1fr;
      }
      .compare-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .features-grid,
      .services-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .hero-title {
        font-size: 30px;
      }
    }