/* roulang page: index */
/* ===== 设计变量与全局重置 ===== */
    :root {
      --primary-deep: #0F172A;
      --primary-gradient-start: #0F172A;
      --primary-gradient-end: #1E3A5F;
      --accent-orange: #F97316;
      --accent-orange-hover: #EA580C;
      --success-green: #10B981;
      --warm-gold: #F59E0B;
      --bg-page: #F8FAFC;
      --bg-card: #FFFFFF;
      --text-main: #0F172A;
      --text-secondary: #475569;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 20px rgba(15, 23, 42, 0.06);
      --shadow-hover: 0 12px 32px rgba(15, 23, 42, 0.12);
      --radius-xl: 24px;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --transition-base: 0.35s ease-out;
      --transition-fast: 0.2s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.6;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button {
      font-family: inherit;
      cursor: pointer;
    }
    /* 自定义容器 */
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航样式 */
    .navbar {
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      transition: box-shadow 0.3s;
    }
    .navbar.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .nav-link {
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 0.5rem 0;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: linear-gradient(to right, var(--accent-orange), #F59E0B);
      transition: width 0.3s ease;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--primary-deep);
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    /* 移动端抽屉 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: 0;
      width: 280px;
      height: 100vh;
      background: white;
      box-shadow: -8px 0 30px rgba(0,0,0,0.15);
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 1000;
      padding: 2rem 1.5rem;
      display: flex;
      flex-direction: column;
    }
    .mobile-drawer.open {
      transform: translateX(0);
    }
    .drawer-overlay {
      position: fixed;
      inset: 0;
      background: rgba(15,23,42,0.5);
      z-index: 999;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s;
    }
    .drawer-overlay.show {
      opacity: 1;
      pointer-events: auto;
    }
    /* 按钮系统 */
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      border-radius: var(--radius-md);
      padding: 0.875rem 2rem;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.3s, transform 0.2s;
      border: none;
      position: relative;
      overflow: hidden;
    }
    .btn-primary:hover {
      background: var(--accent-orange-hover);
      transform: translateY(-2px);
    }
    .btn-primary::after {
      content: '';
      position: absolute;
      top: 0;
      left: -75%;
      width: 50%;
      height: 100%;
      background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
      transform: skewX(-20deg);
      transition: left 0.6s;
    }
    .btn-primary:hover::after {
      left: 125%;
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid white;
      color: white;
      border-radius: var(--radius-md);
      padding: 0.875rem 2rem;
      font-weight: 600;
      transition: all 0.3s;
    }
    .btn-ghost:hover {
      background: white;
      color: var(--primary-deep);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-deep);
      color: var(--primary-deep);
      border-radius: var(--radius-md);
      padding: 0.75rem 1.75rem;
      font-weight: 600;
      transition: all 0.3s;
    }
    .btn-outline:hover {
      background: var(--primary-deep);
      color: white;
    }
    /* 卡片通用 */
    .card-hover {
      transition: transform var(--transition-base), box-shadow var(--transition-base);
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    /* 渐变文字 */
    .gradient-text {
      background: linear-gradient(135deg, var(--primary-deep) 0%, var(--accent-orange) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    /* 数据徽章动态 */
    .badge-pulse {
      animation: pulse-glow 2.4s infinite;
    }
    @keyframes pulse-glow {
      0% { box-shadow: 0 0 0 0 rgba(249,115,22,0.4); }
      70% { box-shadow: 0 0 0 12px rgba(249,115,22,0); }
      100% { box-shadow: 0 0 0 0 rgba(249,115,22,0); }
    }
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      cursor: pointer;
      font-weight: 600;
      color: var(--primary-deep);
      padding: 1.25rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease-in-out, padding 0.3s;
      color: var(--text-body);
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding-bottom: 1.25rem;
    }
    .faq-icon {
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* 计数动画相关 */
    .count-up {
      font-variant-numeric: tabular-nums;
    }
    /* 响应式补充 */
    @media (max-width: 768px) {
      .hero-visual-card {
        margin-top: 2rem;
      }
    }