/* roulang page: index */
:root {
      --primary: #FF4D00;
      --primary-glow: rgba(255, 77, 0, 0.7);
      --secondary: #00F0FF;
      --secondary-glow: rgba(0, 240, 255, 0.5);
      --bg-deep: #0A0E27;
      --bg-card: #141A33;
      --bg-card-hover: #1A2040;
      --text-body: #B0B8D1;
      --text-muted: #6B7394;
      --text-white: #FFFFFF;
      --border-dim: rgba(0, 240, 255, 0.15);
      --border-glow: rgba(0, 240, 255, 0.6);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-pill: 32px;
      --shadow-card: 0 10px 25px -8px rgba(0,0,0,0.4);
      --shadow-btn: 0 0 20px var(--primary-glow);
      --shadow-btn-hover: 0 0 30px rgba(255, 77, 0, 0.8);
      --font-heading: 'Montserrat', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --transition-smooth: all 0.25s cubic-bezier(0.2, 0.0, 0, 1);
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-body);
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, .data-number, .nav-brand {
      font-family: var(--font-heading);
      font-weight: 800;
      color: var(--text-white);
      letter-spacing: -0.02em;
    }
    h1 {
      font-size: 3rem;
      line-height: 1.2;
      font-weight: 900;
      margin-bottom: 1.25rem;
    }
    h2 {
      font-size: 2.25rem;
      line-height: 1.3;
      margin-bottom: 0.75rem;
      font-weight: 800;
    }
    h3 {
      font-size: 1.375rem;
      line-height: 1.4;
      margin-bottom: 0.5rem;
      color: var(--primary);
      font-weight: 700;
    }
    p {
      margin-bottom: 1.25rem;
      color: var(--text-body);
    }
    a {
      color: var(--secondary);
      text-decoration: none;
      transition: var(--transition-smooth);
    }
    a:hover {
      color: var(--secondary-glow);
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    section {
      padding: 6rem 0;
      position: relative;
    }
    @media (max-width: 1024px) {
      section {
        padding: 4.5rem 0;
      }
      h1 {
        font-size: 2.5rem;
      }
      h2 {
        font-size: 2rem;
      }
    }
    @media (max-width: 640px) {
      section {
        padding: 3.5rem 0;
      }
      h1 {
        font-size: 2rem;
      }
      h2 {
        font-size: 1.75rem;
      }
    }

    /* 导航卡片化面板 */
    .top-nav {
      position: sticky;
      top: 15px;
      z-index: 50;
      padding: 0 20px;
      margin-top: 20px;
    }
    .nav-panel {
      background: rgba(10, 14, 39, 0.88);
      backdrop-filter: blur(18px);
      border: 1px solid rgba(0, 240, 255, 0.18);
      border-radius: 50px;
      padding: 0.6rem 1.8rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      box-shadow: 0 12px 28px rgba(0,0,0,0.6);
      max-width: 1300px;
      margin: 0 auto;
    }
    .nav-brand {
      font-size: 1.7rem;
      font-weight: 800;
      color: #fff;
      text-shadow: 0 0 12px var(--secondary-glow);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .nav-brand i {
      color: var(--primary);
      font-size: 1.9rem;
    }
    .nav-links {
      display: flex;
      gap: 0.5rem;
      align-items: center;
      flex-wrap: wrap;
    }
    .nav-item {
      background: rgba(20, 26, 51, 0.6);
      border: 1px solid transparent;
      border-radius: 40px;
      padding: 0.5rem 1.2rem;
      font-weight: 600;
      font-size: 0.9rem;
      color: #cdd6f0;
      display: flex;
      align-items: center;
      gap: 8px;
      transition: var(--transition-smooth);
      white-space: nowrap;
      backdrop-filter: blur(8px);
    }
    .nav-item i {
      color: var(--secondary);
    }
    .nav-item:hover {
      background: rgba(0, 240, 255, 0.12);
      border-color: var(--border-glow);
      color: #fff;
      transform: translateY(-1px);
    }
    .nav-cta {
      background: var(--primary);
      color: #fff;
      border-radius: 50px;
      padding: 0.65rem 1.8rem;
      font-weight: 700;
      border: none;
      box-shadow: 0 0 14px var(--primary-glow);
      transition: var(--transition-smooth);
      margin-left: 1rem;
    }
    .nav-cta:hover {
      background: #FF6B33;
      box-shadow: 0 0 25px rgba(255,77,0,0.8);
      transform: scale(1.03);
    }
    .mobile-menu-btn {
      display: none;
      background: transparent;
      border: none;
      color: var(--secondary);
      font-size: 2rem;
    }
    @media (max-width: 1024px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 80px;
        left: 20px;
        right: 20px;
        background: rgba(10,14,39,0.95);
        backdrop-filter: blur(30px);
        flex-direction: column;
        border-radius: 32px;
        padding: 2rem;
        gap: 1rem;
        border: 1px solid var(--border-dim);
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-menu-btn {
        display: block;
      }
      .nav-cta {
        margin-left: 0;
        align-self: center;
      }
    }

    /* 按钮系统 */
    .btn-primary {
      background: var(--primary);
      color: #fff;
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.5rem;
      font-weight: 700;
      border: none;
      display: inline-block;
      box-shadow: var(--shadow-btn);
      transition: var(--transition-smooth);
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background: #FF6B33;
      box-shadow: var(--shadow-btn-hover);
      transform: translateY(-2px);
      color: #fff;
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--secondary);
      color: var(--secondary);
      border-radius: var(--radius-btn);
      padding: 0.85rem 2.2rem;
      font-weight: 700;
      transition: var(--transition-smooth);
    }
    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.12);
      color: #fff;
      border-color: #fff;
    }

    /* hero 背景图叠加 */
    .hero-bg {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      border-radius: 2rem;
      overflow: hidden;
    }
    .hero-bg::after {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 20% 30%, rgba(10,14,39,0.7) 0%, #0A0E27 100%);
    }

    /* 卡片通用 */
    .card-glow {
      background: var(--bg-card);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-card);
      padding: 2rem;
      transition: var(--transition-smooth);
      backdrop-filter: blur(10px);
      height: 100%;
    }
    .card-glow:hover {
      border-color: var(--border-glow);
      transform: translateY(-6px);
      box-shadow: 0 18px 30px -12px rgba(0,240,255,0.2);
      background: #1a2040;
    }

    /* 非对称布局 */
    .asymmetric-grid {
      display: grid;
      grid-template-columns: 1.4fr 1fr;
      gap: 2rem;
    }
    .stack-cards {
      display: flex;
      flex-direction: column;
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .asymmetric-grid {
        grid-template-columns: 1fr;
      }
    }

    .data-badge {
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 2rem 1rem;
      border-radius: 24px;
      background: rgba(20,26,51,0.7);
      border: 1px solid rgba(0,240,255,0.2);
    }
    .data-number {
      font-size: 2.8rem;
      color: var(--secondary);
      text-shadow: 0 0 16px var(--secondary-glow);
    }

    footer {
      background: #0A0E27;
      border-top: 1px solid rgba(0,240,255,0.15);
    }

    .faq-item {
      background: var(--bg-card);
      border-radius: 12px;
      margin-bottom: 0.8rem;
    }
    .faq-question {
      padding: 1.2rem 1.8rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      color: #fff;
    }
    .faq-answer {
      padding: 0 1.8rem 1.5rem;
      color: var(--text-body);
    }