/* roulang page: index */
:root {
      --purple: #8B00FF;
      --cyan: #00E5FF;
      --dark: #0D0F14;
      --light: #F4F6FA;
      --orange: #FF5E1A;
      --text-primary: #0D0F14;
      --text-secondary: #4B5563;
      --border-light: rgba(255,255,255,0.1);
      --radius-card: 16px;
      --radius-btn: 9999px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: 'Noto Sans SC', sans-serif;
      background-color: var(--dark);
      color: #E5E7EB;
      line-height: 1.6;
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }
    
    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    
    /* 导航样式 */
    .navbar {
      transition: background-color 0.3s ease, backdrop-filter 0.3s ease;
    }
    .navbar.scrolled {
      background-color: rgba(13, 15, 20, 0.9);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .nav-link {
      position: relative;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--cyan);
      transition: width 0.2s ease;
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    
    /* 卡片系统 */
    .glass-card {
      background: rgba(15, 18, 25, 0.7);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: var(--cyan);
      transform: translateY(-4px);
      box-shadow: 0 12px 28px rgba(0,229,255,0.15);
    }
    
    .btn-primary {
      background: linear-gradient(135deg, #8B00FF, #00E5FF);
      border-radius: var(--radius-btn);
      color: white;
      font-weight: 600;
      padding: 0.75rem 2rem;
      transition: all 0.25s;
      box-shadow: 0 4px 12px rgba(139,0,255,0.3);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      box-shadow: 0 0 24px rgba(0,229,255,0.6);
      transform: scale(1.02);
    }
    
    .btn-outline {
      background: transparent;
      border: 1px solid var(--cyan);
      color: var(--cyan);
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      transition: all 0.25s;
    }
    .btn-outline:hover {
      background: rgba(0,229,255,0.1);
      border-color: white;
    }
    
    /* 装饰线条 */
    .section-title {
      position: relative;
      padding-left: 1.5rem;
      font-size: 2.25rem;
      font-weight: 700;
      color: white;
    }
    .section-title::before {
      content: '';
      position: absolute;
      left: 0;
      top: 0.2rem;
      bottom: 0.2rem;
      width: 4px;
      background: var(--cyan);
      border-radius: 2px;
    }
    
    /* 数字动画 */
    .stat-number {
      font-family: 'Inter', monospace;
      font-weight: 700;
      font-feature-settings: "tnum";
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .faq-question {
      cursor: pointer;
      padding: 1.25rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: #9CA3AF;
      line-height: 1.8;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
      color: var(--cyan);
    }
    
    /* 移动端菜单 */
    .mobile-menu {
      transition: transform 0.3s ease;
    }
    
    @media (max-width: 768px) {
      .section-title {
        font-size: 1.8rem;
      }
    }