/* roulang page: index */
:root {
      --primary-black: #0B0E14;
      --accent-cyan: #00F0FF;
      --accent-orange: #FF4D4D;
      --bg-light: #F8FAFC;
      --text-main: #1E293B;
      --text-secondary: #475569;
      --line-color: #E2E8F0;
      --white: #FFFFFF;
      --radius-hard: 2px;
      --shadow-card: 0px 10px 30px -10px rgba(0,0,0,0.05);
      --shadow-hover: 0px 20px 35px -12px rgba(0,0,0,0.08);
      --transition: all 0.2s ease-in-out;
      font-size: 16px;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Inter", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
      width: 100%;
    }

    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.02em;
    }

    h1 {
      font-size: clamp(3.5rem, 8vw, 5rem);
      line-height: 1.15;
      color: var(--primary-black);
    }

    h2 {
      font-size: clamp(2.2rem, 5vw, 3rem);
      font-weight: 600;
      letter-spacing: -0.01em;
      position: relative;
      display: inline-block;
    }

    h2::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 60%;
      height: 2px;
      background: var(--accent-cyan);
      opacity: 0.5;
    }

    .section-title {
      margin-bottom: 2.5rem;
      color: var(--primary-black);
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      font-weight: 600;
      border: none;
      background: transparent;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      white-space: nowrap;
    }

    /* 导航 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(226, 232, 240, 0.4);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 76px;
    }

    .logo {
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--primary-black);
      letter-spacing: -0.5px;
    }

    .logo span {
      color: var(--accent-cyan);
    }

    .nav-links {
      display: flex;
      gap: 2.5rem;
      font-weight: 500;
      color: var(--text-secondary);
    }

    .nav-links a {
      position: relative;
      padding: 0.25rem 0;
      transition: color 0.2s;
    }

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

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.2s ease;
    }

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

    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary-black);
      width: 42px;
      height: 42px;
      align-items: center;
      justify-content: center;
      border-radius: 100px;
      transition: background 0.2s;
    }

    .mobile-menu-btn:hover {
      background: rgba(0,240,255,0.1);
    }

    /* 首屏 */
    .hero {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
      padding: 2.5rem 0 5rem;
      min-height: 85vh;
    }

    .hero-left {
      display: flex;
      flex-direction: column;
      gap: 1.8rem;
    }

    .hero-subtitle {
      font-size: 1.25rem;
      color: var(--text-secondary);
      max-width: 460px;
      border-left: 3px solid var(--accent-cyan);
      padding-left: 1.2rem;
    }

    .cta-group {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
      margin-top: 1rem;
    }

    .btn-primary {
      background: var(--primary-black);
      color: var(--white);
      padding: 0.9rem 2.5rem;
      border-radius: var(--radius-hard);
      font-size: 1.1rem;
    }

    .btn-primary:hover {
      background: var(--accent-cyan);
      color: var(--primary-black);
    }

    .btn-ghost {
      border: 1px solid var(--primary-black);
      color: var(--primary-black);
      padding: 0.9rem 2.5rem;
      border-radius: var(--radius-hard);
      background: transparent;
    }

    .btn-ghost:hover {
      background: rgba(11,14,20,0.05);
    }

    .glass-card {
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border-radius: 6px;
      border: 1px solid rgba(226,232,240,0.6);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
      background-image: linear-gradient(135deg, rgba(0,240,255,0.03) 0%, rgba(255,255,255,0) 100%);
    }

    .live-counter {
      font-family: 'Inter', 'SF Mono', monospace;
      font-size: 2.1rem;
      font-weight: 700;
      color: var(--accent-cyan);
    }

    .grid-bg {
      background-image: radial-gradient(rgba(0,240,255,0.15) 1px, transparent 1px);
      background-size: 18px 18px;
    }

    .stat-item {
      display: flex;
      justify-content: space-between;
      font-size: 0.95rem;
    }

    /* 数据看板 */
    .dashboard {
      padding: 5rem 0;
    }

    .metric-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 1rem;
    }

    .metric-card {
      background: var(--white);
      padding: 2.5rem 1.5rem;
      text-align: center;
      box-shadow: var(--shadow-card);
      border-radius: var(--radius-hard);
      transition: var(--transition);
      border: 1px solid transparent;
    }

    .metric-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
      border-left: 4px solid var(--accent-cyan);
    }

    .metric-number {
      font-family: 'Inter', 'SF Mono', monospace;
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--primary-black);
    }

    .metric-label {
      color: var(--text-secondary);
      margin-top: 0.5rem;
    }

    /* 服务矩阵 非对称 */
    .services {
      padding: 5rem 0;
    }

    .service-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 1.5rem;
    }

    .service-left {
      background: var(--white);
      border-radius: var(--radius-hard);
      padding: 2.5rem;
      box-shadow: var(--shadow-card);
      position: relative;
      overflow: hidden;
    }

    .watermark {
      position: absolute;
      right: 2rem;
      top: 1rem;
      font-size: 5rem;
      font-weight: 700;
      color: rgba(0,240,255,0.06);
      pointer-events: none;
    }

    .service-right {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }

    .service-card {
      background: var(--white);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      border-radius: var(--radius-hard);
      transition: var(--transition);
      border: 1px solid transparent;
    }

    .service-card:hover {
      transform: translateY(-6px);
      border-left: 4px solid var(--accent-cyan);
    }

    /* 技术架构 */
    .architecture {
      padding: 5rem 0;
      background: var(--white);
    }

    .arch-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }

    .flow-chart {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 1rem;
      flex-wrap: wrap;
    }

    .node {
      width: 16px;
      height: 16px;
      background: var(--accent-cyan);
      border-radius: 50%;
    }

    .line {
      width: 48px;
      height: 2px;
      background: #CBD5E1;
    }

    .compare-bar {
      display: flex;
      flex-direction: column;
      gap: 1.8rem;
    }

    .bar-item {
      display: flex;
      align-items: center;
      gap: 1rem;
    }

    .bar-fill {
      height: 12px;
      background: var(--accent-cyan);
      width: 0%;
      transition: width 1s ease;
    }

    /* FAQ */
    .faq {
      padding: 5rem 0;
      background: rgba(11,14,20,0.02);
    }

    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1.8fr;
      gap: 2rem;
    }

    .accordion-item {
      background: var(--white);
      border: 1px solid var(--line-color);
      margin-bottom: 0.8rem;
      border-radius: 2px;
    }

    .accordion-header {
      padding: 1.2rem 1.5rem;
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      cursor: pointer;
    }

    .accordion-body {
      padding: 0 1.5rem 1.2rem;
      color: var(--text-secondary);
      display: none;
    }

    .accordion-item.active .accordion-body {
      display: block;
    }
    .accordion-item.active {
      border-left: 4px solid var(--accent-cyan);
    }

    /* CTA */
    .cta-section {
      padding: 5rem 0;
      text-align: center;
    }

    .cta-box {
      max-width: 650px;
      margin: 0 auto;
    }

    .form-divider {
      display: flex;
      flex-direction: column;
      gap: 1.2rem;
      margin: 2rem 0;
    }

    .input-line {
      border: none;
      border-bottom: 1px solid var(--line-color);
      padding: 1rem 0;
      font-size: 1rem;
      background: transparent;
      width: 100%;
    }

    .btn-submit {
      background: var(--primary-black);
      color: white;
      padding: 1rem 3rem;
      font-size: 1.1rem;
    }

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

    /* Footer */
    .footer {
      background: #0B0E14;
      color: #CBD5E1;
      padding: 3.5rem 0 2rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 2rem;
      margin: 2rem 0;
    }

    @media (max-width: 1024px) {
      .service-grid, .arch-grid {
        grid-template-columns: 1fr;
      }
      .faq-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 1.5rem;
      }
      .nav-links {
        display: none;
      }
      .mobile-menu-btn {
        display: flex;
      }
      .hero {
        grid-template-columns: 1fr;
        text-align: left;
        padding: 1rem 0 3rem;
      }
      .metric-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .cta-group {
        flex-direction: column;
      }
      .nav-container {
        height: 70px;
      }
    }