/* roulang page: index */
/* 全局设计变量与重置 */
    :root {
      --primary: #7B2FF7;
      --primary-glow: rgba(123, 47, 247, 0.6);
      --accent: #00F0FF;
      --accent-glow: rgba(0, 240, 255, 0.3);
      --bg-deep: #0A0C12;
      --card-bg: #131620;
      --card-border: rgba(123, 47, 247, 0.15);
      --text-primary: #FFFFFF;
      --text-secondary: #B0B8C5;
      --text-muted: #5A6070;
      --border-light: rgba(255, 255, 255, 0.05);
      --font-sans: 'Inter', 'PingFang SC', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      --font-mono: 'DIN Alternate', 'Inter', monospace;
      --radius-card: 16px;
      --radius-btn: 50px;
      --shadow-card: 0 0 20px rgba(123, 47, 247, 0.1);
      --transition-bounce: cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-secondary);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
      overflow-x: hidden;
    }

    /* 自定义容器 */
    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 背景装饰网格 */
    .bg-grid-pattern {
      background-image: 
        linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
      background-size: 40px 40px;
    }

    /* 导航样式 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      z-index: 50;
      transition: background-color 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease;
      background: rgba(0, 0, 0, 0.4);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    .navbar.scrolled {
      background: #0B0E14;
      backdrop-filter: none;
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }

    .nav-link {
      color: var(--text-secondary);
      font-weight: 500;
      transition: color 0.2s;
      position: relative;
      padding: 8px 4px;
      text-decoration: none;
      font-size: 0.95rem;
    }
    .nav-link:hover {
      color: var(--accent);
    }
    .nav-link.active {
      color: var(--primary);
      border-bottom: 2px solid var(--primary);
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.3s var(--transition-bounce);
      border: none;
      cursor: pointer;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(123,47,247,0.3);
    }
    .btn-primary:hover {
      background: #9350FF;
      box-shadow: 0 0 18px var(--primary-glow);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.3s var(--transition-bounce);
      cursor: pointer;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-outline:hover {
      background: var(--accent);
      color: #0A0C12;
      box-shadow: 0 0 15px var(--accent-glow);
    }

    /* 卡片通用 */
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      border: 1px solid var(--card-border);
      padding: 32px;
      transition: all 0.3s var(--transition-bounce);
    }
    .card:hover {
      border-color: var(--primary);
      box-shadow: 0 0 25px rgba(123,47,247,0.25);
      transform: translateY(-4px);
    }

    /* 数据大数字 */
    .stat-number {
      font-family: var(--font-mono);
      font-size: 48px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.2;
    }

    /* 粒子画布 */
    #particle-canvas {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }

    /* FAQ手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      transition: background 0.2s;
    }
    .faq-question {
      background: var(--card-bg);
      padding: 20px 16px;
      font-weight: 600;
      font-size: 1.1rem;
      color: white;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      transition: background 0.2s;
      border-left: 0px solid var(--primary);
    }
    .faq-item.active .faq-question {
      background: #181C26;
      border-left: 4px solid var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      background: #181C26;
      color: var(--text-secondary);
      padding: 0 16px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    .faq-icon {
      color: var(--accent);
      font-size: 1.5rem;
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 表单样式 */
    .form-input {
      background: #1A1D28;
      border: none;
      border-bottom: 2px solid #2A2F3C;
      padding: 14px 12px;
      color: white;
      width: 100%;
      border-radius: 6px;
      transition: border 0.2s, box-shadow 0.2s;
      outline: none;
    }
    .form-input:focus {
      border-bottom-color: var(--accent);
      box-shadow: 0 0 8px var(--accent-glow);
    }
    .form-input::placeholder {
      color: #5A6070;
    }

    /* 移动端底部导航 */
    .mobile-nav {
      display: none;
    }

    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: #131620;
        border-top: 1px solid rgba(123,47,247,0.2);
        border-radius: 40px 40px 0 0;
        padding: 8px 16px;
        justify-content: space-around;
        z-index: 50;
        backdrop-filter: blur(12px);
      }
      .mobile-nav a {
        display: flex;
        flex-direction: column;
        align-items: center;
        color: #B0B8C5;
        font-size: 0.7rem;
        text-decoration: none;
        transition: color 0.2s;
      }
      .mobile-nav a i {
        font-size: 1.3rem;
        margin-bottom: 2px;
      }
      .mobile-nav a.active {
        color: var(--primary);
      }
      h1 {
        font-size: 36px !important;
      }
      h2 {
        font-size: 28px !important;
      }
      .stat-number {
        font-size: 36px;
      }
    }