/* roulang page: index */
/* 完整设计系统变量与自定义视觉 */
    :root {
      --primary-deep: #0B1D3A;
      --accent-cyan: #00E5FF;
      --accent-orange: #FF6B35;
      --bg-dark: #0A0F1F;
      --bg-gradient: linear-gradient(135deg, #0A0F1F 0%, #0B1D3A 100%);
      --text-primary: #F0F4FF;
      --text-secondary: #B0C7E0;
      --text-muted: #6A7F9B;
      --glass-bg: rgba(255,255,255,0.03);
      --glass-border: rgba(255,255,255,0.08);
      --glass-highlight: rgba(0,229,255,0.15);
      --card-shadow: 0 8px 32px rgba(0,0,0,0.4);
      --card-hover-shadow: 0 12px 40px rgba(0,0,0,0.6), 0 0 30px rgba(0,229,255,0.2);
      --button-glow: 0 0 20px rgba(0,229,255,0.5);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 8px;
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --font-sans: 'Noto Sans SC', 'Inter', 'Roboto', system-ui, -apple-system, sans-serif;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      font-family: var(--font-sans);
      background: var(--bg-dark);
      color: var(--text-primary);
      line-height: 1.6;
      margin: 0;
      padding: 0;
      background-image: var(--bg-gradient);
      background-attachment: fixed;
      -webkit-font-smoothing: antialiased;
      position: relative;
    }
    
    /* 全局网格背景纹理（赛场线意象） */
    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: 
        linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
      z-index: 0;
    }
    
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
      position: relative;
      z-index: 1;
    }
    
    /* 导航个意见 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10, 15, 31, 0.85);
      backdrop-filter: blur(30px);
      -webkit-backdrop-filter: blur(30px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
      z-index: 50;
      transition: var(--transition-smooth);
      display: flex;
      align-items: center;
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 800;
      font-size: 1.5rem;
      color: white;
      text-decoration: none;
      letter-spacing: 1px;
    }
    .logo i {
      color: var(--accent-cyan);
      font-size: 1.8rem;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      transition: color 0.2s;
      font-size: 1rem;
    }
    .nav-links a:hover {
      color: var(--accent-cyan);
    }
    .btn-primary {
      background: linear-gradient(135deg, #00E5FF, #00B8D4);
      border: none;
      padding: 0.6rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      color: #0A0F1F;
      cursor: pointer;
      box-shadow: var(--button-glow);
      transition: var(--transition-smooth);
      text-decoration: none;
      display: inline-block;
    }
    .btn-primary:hover {
      box-shadow: 0 0 40px rgba(0,229,255,0.8);
      transform: scale(1.05);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 0.6rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition-smooth);
      text-decoration: none;
    }
    .btn-outline:hover {
      background: rgba(0,229,255,0.1);
      box-shadow: 0 0 20px rgba(0,229,255,0.3);
    }
    /* 移动端导航仅使用底部胶囊 (桌面端隐藏) */
    .mobile-bottom-nav {
      display: none;
    }
    
    /* hero数据看板光效 */
    .data-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 1.5rem;
      box-shadow: 0 8px 32px rgba(0,0,0,0.5), inset 0 0 15px var(--glass-highlight);
    }
    .pulse-glow {
      animation: softPulse 3s infinite;
    }
    @keyframes softPulse {
      0% { box-shadow: 0 0 10px rgba(0,229,255,0.1); }
      50% { box-shadow: 0 0 25px rgba(0,229,255,0.4); }
      100% { box-shadow: 0 0 10px rgba(0,229,255,0.1); }
    }
    
    /* 对比表进度条 */
    .progress-bar {
      height: 8px;
      border-radius: 4px;
      background: rgba(255,255,255,0.1);
    }
    .progress-fill.cyan {
      background: linear-gradient(90deg, #00E5FF, #00B8D4);
      width: 90%;
    }
    .progress-fill.gray {
      background: #4B5563;
      width: 65%;
    }
    
    /* FAQ 手风琴效果 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .faq-question {
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1.2rem 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s ease;
      color: var(--text-secondary);
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1.2rem;
    }
    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
      color: var(--accent-cyan);
    }