/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent-cyan: #00F0FF;
      --accent-violet: #7B2FFF;
      --bg-deep: #060918;
      --card-bg: rgba(255, 255, 255, 0.03);
      --card-border: rgba(255, 255, 255, 0.08);
      --text-title: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6B7B8D;
      --glass-blur: blur(20px) saturate(180%);
      --border-radius-lg: 16px;
      --border-radius-md: 12px;
      --border-radius-sm: 8px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-glow: 0 0 40px rgba(0,240,255,0.08);
      --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      --container-max: 1200px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }
    .container {
      max-width: var(--container-max);
      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%;
      z-index: 1000;
      background: rgba(6, 9, 24, 0.85);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
      height: 72px;
      display: flex;
      align-items: center;
    }
    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-weight: 800;
      font-size: 1.5rem;
      background: linear-gradient(135deg, var(--accent-cyan), #4ad9ff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.02em;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover {
      color: var(--accent-cyan);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .menu-toggle {
      display: none;
      background: transparent;
      border: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
    }
    .menu-toggle span {
      display: block;
      width: 26px;
      height: 2px;
      background: var(--accent-cyan);
      border-radius: 2px;
      transition: 0.3s;
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: rgba(6,9,24,0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        transform: translateX(100%);
        transition: transform 0.4s ease;
        z-index: 999;
      }
      .nav-links.active {
        transform: translateX(0);
      }
      .nav-links a {
        font-size: 1.5rem;
        font-weight: 600;
      }
      .menu-toggle {
        display: flex;
      }
      .header {
        height: 64px;
      }
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 64px 0;
      }
    }

    /* Hero */
    .hero {
      padding-top: 140px;
      padding-bottom: 80px;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-title {
      font-size: 3rem;
      font-weight: 800;
      line-height: 1.2;
      color: var(--text-title);
      letter-spacing: -0.02em;
    }
    .hero-title span {
      background: linear-gradient(to right, var(--accent-cyan), #7ad9ff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-desc {
      margin: 24px 0 32px;
      font-size: 1.125rem;
      color: var(--text-body);
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--border-radius-md);
      transition: var(--transition-smooth);
      cursor: pointer;
      border: none;
      font-size: 1rem;
      padding: 0 28px;
      height: 48px;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--accent-cyan) 0%, var(--accent-violet) 100%);
      color: #FFFFFF;
      box-shadow: 0 4px 20px rgba(0,240,255,0.4);
      height: 56px;
      padding: 0 40px;
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 30px rgba(0,240,255,0.6);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid rgba(0,240,255,0.5);
      color: var(--accent-cyan);
    }
    .btn-secondary:hover {
      background: rgba(0,240,255,0.08);
      border-color: var(--accent-cyan);
    }
    .hero-image {
      background: rgba(255,255,255,0.02);
      backdrop-filter: blur(16px);
      border-radius: 24px;
      padding: 20px;
      border: 1px solid rgba(255,255,255,0.1);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-image img {
      border-radius: 16px;
      width: 100%;
      height: auto;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
      }
      .hero-title {
        font-size: 2.2rem;
      }
      .btn-group {
        justify-content: center;
      }
      .hero-desc {
        margin-left: auto;
        margin-right: auto;
      }
      .hero {
        padding-top: 100px;
      }
    }

    /* 标题通用 */
    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      color: var(--text-title);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      color: var(--text-muted);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }

    /* 优势卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .glass-card {
      background: linear-gradient(135deg, rgba(255,255,255,0.04) 0%, rgba(255,255,255,0.01) 100%);
      backdrop-filter: var(--glass-blur);
      -webkit-backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--border-radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }
    .glass-card:hover {
      border-color: rgba(0,240,255,0.3);
      box-shadow: var(--shadow-glow), var(--shadow-card);
      transform: translateY(-4px);
    }
    .icon-box {
      width: 48px;
      height: 48px;
      background: rgba(0,240,255,0.08);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent-cyan);
      font-size: 1.5rem;
      border: 1px solid rgba(0,240,255,0.25);
    }
    .card-title {
      font-size: 1.25rem;
      font-weight: 600;
      color: white;
      margin-bottom: 8px;
    }
    @media (max-width: 768px) {
      .cards-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 功能分组交替 */
    .feature-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }
    .feature-reverse {
      direction: rtl;
    }
    .feature-reverse > * {
      direction: ltr;
    }
    .feature-text h3 {
      font-size: 1.8rem;
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
    }
    .feature-list {
      list-style: none;
      margin-top: 24px;
    }
    .feature-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 16px;
      color: var(--text-body);
    }
    .feature-list i {
      color: var(--accent-violet);
      font-size: 0.9rem;
      margin-top: 4px;
    }
    .feature-preview {
      background: rgba(255,255,255,0.02);
      border-radius: 20px;
      padding: 20px;
      border: 1px solid rgba(255,255,255,0.1);
    }
    .feature-preview img {
      border-radius: 12px;
      width: 100%;
    }
    @media (max-width: 768px) {
      .feature-row {
        grid-template-columns: 1fr;
        gap: 32px;
      }
    }

    /* 场景卡片 */
    .scenario-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .scenario-card img {
      border-radius: 12px 12px 0 0;
      height: 180px;
      object-fit: cover;
    }
    .tag {
      display: inline-block;
      background: rgba(0,240,255,0.1);
      color: var(--accent-cyan);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 500;
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .scenario-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 数据案例 */
    .stats-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
    }
    .big-number {
      font-size: 4rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--accent-cyan), var(--accent-violet));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      line-height: 1;
      margin-bottom: 8px;
    }
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .faq-question {
      background: transparent;
      width: 100%;
      text-align: left;
      padding: 20px 0;
      font-weight: 600;
      font-size: 1.1rem;
      color: white;
      display: flex;
      justify-content: space-between;
      align-items: center;
      border: none;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-body);
      padding-bottom: 0;
    }
    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 16px;
    }

    /* CTA */
    .cta-section {
      background: radial-gradient(circle at center, rgba(123,47,255,0.08) 0%, transparent 70%);
      text-align: center;
    }
    .trust-badge {
      color: var(--text-muted);
      font-size: 0.9rem;
      margin-top: 16px;
    }
    
    footer {
      background: var(--bg-deep);
      border-top: 1px solid rgba(255,255,255,0.05);
      padding: 32px 0;
      color: var(--text-muted);
      font-size: 0.9rem;
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }
    a:hover {
      color: var(--accent-cyan);
    }