/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary-bg: #0A0E27;
      --card-bg: #1A1F3A;
      --accent-cyan: #00F0FF;
      --accent-rose: #FF3A6F;
      --text-white: #FFFFFF;
      --text-gray: #A0AEC0;
      --text-muted: #718096;
      --border-dim: rgba(0, 240, 255, 0.15);
      --border-glow: #00F0FF;
      --shadow-glow: 0 8px 25px rgba(0, 240, 255, 0.2);
      --font-mono: "SF Mono", "Menlo", "Monaco", "Consolas", monospace;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--primary-bg);
      color: var(--text-white);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease, background 0.2s ease;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: all 0.25s ease;
      border: none;
      outline: none;
    }
    
    input, textarea {
      font-family: inherit;
      outline: none;
    }
    
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    
    /* 导航定制 */
    .nav-blur {
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid rgba(0,0,0,0.05);
    }
    
    .nav-link {
      color: #4A5568;
      font-weight: 500;
      transition: color 0.2s;
      position: relative;
    }
    .nav-link:hover {
      color: var(--accent-cyan);
    }
    .nav-link.active {
      color: var(--accent-cyan);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-cyan);
      box-shadow: 0 0 8px var(--accent-cyan);
    }
    
    /* 卡片风格 */
    .card {
      background-color: var(--card-bg);
      border: 1px solid var(--border-dim);
      border-radius: 12px;
      transition: all 0.3s ease;
    }
    .card:hover {
      border-color: var(--border-glow);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }
    
    /* 按钮 */
    .btn-primary {
      background: var(--accent-cyan);
      color: var(--primary-bg);
      font-weight: 700;
      border-radius: 8px;
      padding: 0.75rem 1.8rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      letter-spacing: 0.5px;
      box-shadow: 0 4px 14px rgba(0, 240, 255, 0.3);
    }
    .btn-primary:hover {
      background: #33F5FF;
      box-shadow: 0 6px 20px rgba(0, 240, 255, 0.5);
      transform: translateY(-1px);
    }
    
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      border-radius: 8px;
      padding: 0.7rem 1.8rem;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
    }
    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.08);
      box-shadow: 0 0 15px rgba(0, 240, 255, 0.2);
    }
    
    /* 对比组件动画 */
    @keyframes pulse-border {
      0% { border-color: rgba(0, 240, 255, 0.5); }
      50% { border-color: rgba(0, 240, 255, 1); box-shadow: 0 0 12px rgba(0,240,255,0.3); }
      100% { border-color: rgba(0, 240, 255, 0.5); }
    }
    .pulse-glow {
      animation: pulse-border 2s infinite;
    }
    
    /* 移动端菜单 */
    @media (max-width: 768px) {
      .mobile-hidden {
        display: none;
      }
      .mobile-flex {
        display: flex;
      }
    }
    
    /* FAQ手风琴过渡 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    .faq-item.open .faq-content {
      max-height: 300px;
    }
    .faq-indicator {
      transition: transform 0.3s;
    }
    .faq-item.open .faq-indicator {
      transform: rotate(45deg);
    }