/* roulang page: index */
:root {
      --primary-deep: #0A0F1E;
      --accent-neon: #00F5A0;
      --purple-algo: #B44DFF;
      --amber-data: #FFB800;
      --card-bg: #1A1F2E;
      --text-primary: #F0F2F5;
      --text-secondary: #B0B8C1;
      --text-muted: #6B7280;
      --border-dim: rgba(0, 245, 160, 0.18);
      --border-active: #00F5A0;
      --radius-card: 16px;
      --radius-btn: 12px;
      --shadow-card: 0 8px 24px rgba(0, 0, 0, 0.55);
      --shadow-glow: 0 0 20px rgba(0, 245, 160, 0.6);
      --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      background-color: var(--primary-deep);
      color: var(--text-primary);
      line-height: 1.75;
      margin: 0;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 导航栏 */
    .header-nav {
      background: rgba(10, 15, 30, 0.94);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 245, 160, 0.2);
      position: sticky;
      top: 0;
      z-index: 50;
    }

    .logo-text {
      font-weight: 800;
      font-size: 1.5rem;
      letter-spacing: 1px;
      background: linear-gradient(135deg, #00F5A0 0%, #B44DFF 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .nav-link {
      color: var(--text-secondary);
      font-weight: 500;
      padding: 0.5rem 0.25rem;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link:hover,
    .nav-link.active {
      color: #00F5A0;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -2px;
      width: 0%;
      height: 2px;
      background: #00F5A0;
      transition: width 0.25s ease;
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }

    .search-input {
      background: #1A1F2E;
      border: 1px solid rgba(255,255,255,0.08);
      border-radius: 24px;
      padding: 0.5rem 1rem;
      color: white;
      outline: none;
      transition: border 0.2s;
      width: 160px;
    }
    .search-input:focus {
      border-color: #00F5A0;
      box-shadow: 0 0 8px rgba(0,245,160,0.4);
    }

    .btn-primary {
      background: #00F5A0;
      color: #0A0F1E;
      font-weight: 700;
      border-radius: 12px;
      padding: 0.7rem 2rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s;
      border: none;
      cursor: pointer;
      letter-spacing: 0.3px;
      box-shadow: 0 4px 12px rgba(0,245,160,0.25);
    }
    .btn-primary:hover {
      background: #00e68a;
      box-shadow: var(--shadow-glow);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid #00F5A0;
      color: #00F5A0;
      font-weight: 700;
      border-radius: 12px;
      padding: 0.7rem 2rem;
      transition: all 0.25s;
      cursor: pointer;
    }
    .btn-outline:hover {
      background: #00F5A0;
      color: #0A0F1E;
      box-shadow: 0 0 16px rgba(0,245,160,0.5);
    }

    .card-hover {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      border: 1px solid var(--border-dim);
      transition: all 0.3s ease;
      box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    }
    .card-hover:hover {
      border-color: #00F5A0;
      transform: translateY(-6px);
      box-shadow: var(--shadow-card);
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 800;
      letter-spacing: -0.5px;
      position: relative;
      display: inline-block;
      margin-bottom: 2.5rem;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -12px;
      width: 56px;
      height: 4px;
      background: #00F5A0;
      border-radius: 4px;
    }

    .amber-num {
      color: var(--amber-data);
      font-weight: 700;
      font-family: var(--font-mono);
    }

    .neon-icon {
      color: #00F5A0;
    }

    .faq-card {
      background: #1A1F2E;
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: 14px;
      transition: border 0.2s;
    }
    .faq-card.active {
      border-color: #00F5A0;
      background: #1E2433;
    }

    /* 移动端汉堡菜单 */
    .mobile-menu {
      display: none;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu {
        display: block;
      }
      .section-title {
        font-size: 1.9rem;
      }
      .hero-left, .hero-right {
        width: 100%;
      }
    }

    .hash-bg-visual {
      background: radial-gradient(circle at 30% 40%, rgba(0,245,160,0.08) 0%, transparent 60%);
    }