/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-dark: #154E63;
      --secondary: #F28C38;
      --secondary-hover: #E07B2C;
      --bg-light: #F7F9FB;
      --bg-white: #FFFFFF;
      --bg-dark: #0F1A24;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --text-light: #94A3B8;
      --border-light: #E2E8F0;
      --success: #10B981;
      --danger: #EF4444;
      --shadow-xs: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-md: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --shadow-nav: 0 2px 12px rgba(0,0,0,0.04);
      --radius-card: 0.75rem;
      --radius-btn: 0.5rem;
      --radius-input: 0.5rem;
      --font-mono: 'SF Mono', 'Cascadia Code', 'Consolas', monospace;
      --transition: all 0.2s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      color: var(--text-main);
      background: var(--bg-white);
      line-height: 1.75;
      margin: 0;
      padding-top: 64px;
    }
    h1, h2, h3, h4, .h1, .h2, .h3 {
      font-weight: 600;
      letter-spacing: -0.01em;
    }
    a {
      color: var(--primary);
      text-decoration: none;
      transition: var(--transition);
    }
    a:hover {
      color: var(--primary-dark);
      text-decoration: underline;
    }
    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航 */
    .navbar {
      height: 64px;
      background: var(--bg-white);
      box-shadow: none;
      transition: var(--transition);
      padding: 0 2rem;
    }
    .navbar.scrolled {
      box-shadow: var(--shadow-nav);
    }
    .navbar-brand {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary) !important;
      letter-spacing: -0.02em;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .brand-icon {
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .nav-link {
      color: var(--text-secondary) !important;
      font-size: 0.95rem;
      font-weight: 500;
      margin: 0 0.25rem;
      padding: 0.5rem 0.9rem !important;
      border-radius: 6px;
      transition: var(--transition);
      position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary) !important;
      background: transparent;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0.9rem;
      right: 0.9rem;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-nav-cta {
      background: var(--secondary);
      color: white !important;
      border-radius: var(--radius-btn);
      padding: 0.5rem 1.4rem !important;
      font-weight: 600;
      font-size: 0.9rem;
      border: none;
      transition: var(--transition);
      margin-left: 0.75rem;
    }
    .btn-nav-cta:hover {
      background: var(--secondary-hover);
      transform: scale(1.02);
      color: white !important;
    }
    .navbar-toggler {
      border: none;
      color: var(--text-main);
    }
    .navbar-toggler:focus {
      box-shadow: none;
    }
    @media (max-width: 991px) {
      .navbar-collapse {
        background: white;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        height: 100vh;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        z-index: 1050;
        padding: 2rem;
      }
      .navbar-collapse .navbar-nav {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
      }
      .nav-link {
        font-size: 1.3rem;
      }
      .btn-nav-cta {
        margin-left: 0;
        margin-top: 1rem;
        padding: 0.8rem 2rem;
        font-size: 1.1rem;
      }
    }
    /* Hero */
    #hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: var(--bg-white);
      position: relative;
      overflow: hidden;
    }
    .hero-visual {
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .signal-circle {
      position: absolute;
      width: 280px;
      height: 280px;
      border: 2px solid rgba(26, 95, 122, 0.15);
      border-radius: 50%;
      animation: pulse 2.5s infinite ease-out;
    }
    .signal-circle:nth-child(2) {
      width: 210px;
      height: 210px;
      animation-delay: 0.4s;
    }
    .signal-circle:nth-child(3) {
      width: 140px;
      height: 140px;
      animation-delay: 0.8s;
      border-color: rgba(26, 95, 122, 0.25);
    }
    @keyframes pulse {
      0% { transform: scale(0.9); opacity: 0.6; }
      100% { transform: scale(1.8); opacity: 0; }
    }
    .data-number-jump {
      font-family: var(--font-mono);
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--primary);
    }
    /* 区块通用 */
    section {
      padding: 5rem 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 3rem 0;
      }
    }
    .section-label {
      font-size: 0.875rem;
      font-weight: 600;
      letter-spacing: 0.5px;
      color: var(--primary);
      text-transform: uppercase;
      margin-bottom: 0.5rem;
      font-family: var(--font-mono);
    }
    /* 指标卡片 */
    .metric-card {
      background: #F8FAFC;
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      text-align: center;
      border-bottom: 3px solid var(--primary);
      transition: var(--transition);
      height: 100%;
    }
    .metric-value {
      font-family: var(--font-mono);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: -0.03em;
    }
    /* 服务矩阵 */
    .service-main-card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 2rem;
      display: flex;
      gap: 2rem;
      transition: var(--transition);
      height: 100%;
    }
    .service-main-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-sub-card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      text-align: center;
      transition: var(--transition);
      height: 100%;
    }
    .service-sub-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--primary);
    }
    /* 对比表格 */
    .compare-col {
      background: #F7F9FB;
      border-radius: var(--radius-card);
      padding: 2rem;
    }
    .compare-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.75rem 0;
      border-bottom: 1px solid var(--border-light);
    }
    /* FAQ */
    .accordion-button {
      font-weight: 600;
      font-size: 1.1rem;
      color: var(--text-main);
      background: white;
      box-shadow: none;
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 1.5rem;
    }
    .accordion-button:not(.collapsed) {
      background: #F7F9FB;
      color: var(--primary);
    }
    .accordion-body {
      color: var(--text-secondary);
      line-height: 1.8;
      padding: 1.5rem;
    }
    /* CTA 表单 */
    #cta {
      background: linear-gradient(135deg, #1A5F7A 0%, #0F3D4F 100%);
      color: white;
    }
    .form-control {
      background: rgba(255,255,255,0.15);
      border: 1px solid rgba(255,255,255,0.3);
      color: white;
      border-radius: var(--radius-input);
      padding: 0.75rem 1rem;
    }
    .form-control::placeholder {
      color: rgba(255,255,255,0.6);
    }
    .form-control:focus {
      background: rgba(255,255,255,0.25);
      border-color: white;
      box-shadow: none;
      color: white;
    }
    .btn-cta-submit {
      background: var(--secondary);
      border: none;
      color: white;
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      transition: var(--transition);
      width: 100%;
    }
    .btn-cta-submit:hover {
      background: var(--secondary-hover);
      transform: scale(1.02);
    }
    /* 页脚 */
    footer {
      background: var(--bg-dark);
      color: var(--text-light);
      padding: 3rem 0 1.5rem;
    }
    footer a {
      color: var(--text-light);
    }
    footer a:hover {
      color: white;
    }
    .social-icon {
      font-size: 1.4rem;
      margin-right: 1rem;
      color: var(--text-light);
    }
    @media (max-width: 768px) {
      .service-main-card {
        flex-direction: column;
      }
      .hero-visual {
        margin-top: 2rem;
      }
    }