/* roulang page: index */
:root {
      --primary: #00F0FF;
      --primary-glow: #33F5FF;
      --primary-dark-bg: #0A0E27;
      --secondary-bg: #0F1429;
      --card-bg: #141B2D;
      --card-bg-alt: #1A1F35;
      --border-color: #1E2640;
      --text-main: #E8ECF1;
      --text-secondary: #8892A4;
      --text-muted: #B0B8C8;
      --accent-red: #FF4655;
      --font-mono: 'JetBrains Mono', monospace;
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --radius-sm: 6px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --shadow-light: 0 2px 8px rgba(0,0,0,0.3);
      --shadow-glow: 0 0 20px rgba(0,240,255,0.5);
      --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-dark-bg);
      color: var(--text-main);
      margin: 0;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-smooth);
    }

    .container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 16px;
      padding-right: 16px;
    }

    @media (min-width: 768px) {
      .container {
        padding-left: 32px;
        padding-right: 32px;
      }
    }

    @media (min-width: 1024px) {
      .container {
        padding-left: 40px;
        padding-right: 40px;
      }
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease, border-bottom 0.3s ease;
    }

    .navbar.scrolled {
      background: rgba(10, 14, 39, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
    }

    .nav-link {
      position: relative;
      font-weight: 500;
      color: var(--text-main);
      padding: 4px 0;
      transition: color var(--transition-smooth);
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--primary);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
    }

    .mobile-menu {
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      background: rgba(10, 14, 39, 0.98);
      backdrop-filter: blur(16px);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      z-index: 40;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s ease;
    }

    .mobile-menu.open {
      opacity: 1;
      pointer-events: auto;
    }

    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: #0A0E27;
      font-weight: 600;
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      cursor: pointer;
      transition: all var(--transition-smooth);
      letter-spacing: 0.02em;
      box-shadow: 0 0 0 rgba(0,240,255,0);
    }

    .btn-primary:hover {
      background: #33F5FF;
      box-shadow: 0 0 20px rgba(0,240,255,0.5);
      transform: scale(1.03);
    }

    .btn-primary:active {
      transform: scale(0.97);
    }

    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all var(--transition-smooth);
    }

    .btn-secondary:hover {
      background: rgba(0,240,255,0.08);
      box-shadow: 0 0 12px rgba(0,240,255,0.3);
    }

    .btn-accent {
      background: var(--accent-red);
      color: white;
      font-weight: 600;
      border-radius: var(--radius-sm);
      padding: 14px 36px;
      border: none;
      cursor: pointer;
      transition: all var(--transition-smooth);
    }

    .btn-accent:hover {
      box-shadow: 0 0 24px rgba(255,70,85,0.6);
      transform: scale(1.03);
    }

    /* 区块间距 */
    section {
      padding: 80px 0;
    }

    @media (max-width: 767px) {
      section {
        padding: 60px 0;
      }
    }

    /* 装饰线 */
    .section-title-decor {
      width: 40px;
      height: 3px;
      background: var(--primary);
      margin-top: 8px;
      margin-bottom: 24px;
    }

    /* 粒子背景 */
    .particle {
      position: absolute;
      border-radius: 50%;
      background: var(--primary);
      opacity: 0.3;
      animation: floatUp linear infinite;
    }

    @keyframes floatUp {
      0% {
        transform: translateY(20px) scale(0.8);
        opacity: 0.2;
      }
      100% {
        transform: translateY(-100px) scale(1.2);
        opacity: 0.6;
      }
    }

    /* 卡片 */
    .card-dark {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: border-color var(--transition-smooth), transform var(--transition-smooth), box-shadow var(--transition-smooth);
    }

    .card-dark:hover {
      border-color: var(--primary);
      box-shadow: 0 8px 24px rgba(0,0,0,0.4);
      transform: translateY(-4px);
    }

    .card-testimonial {
      background: linear-gradient(135deg, #141B2D 0%, #1A1F35 100%);
      border: 1px solid transparent;
      border-radius: var(--radius-lg);
      padding: 32px;
      position: relative;
      transition: all var(--transition-smooth);
    }

    .card-testimonial:hover {
      border-color: var(--primary);
      transform: translateY(-6px);
    }

    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-color);
    }

    .faq-question {
      cursor: pointer;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 1.1rem;
      color: white;
      transition: color var(--transition-smooth);
    }

    .faq-question:hover {
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease;
      color: var(--text-secondary);
      line-height: 1.7;
    }

    .faq-item.open .faq-answer {
      max-height: 300px;
      padding-bottom: 20px;
    }

    .faq-icon {
      transition: transform 0.3s ease;
      font-size: 1.2rem;
      color: var(--primary);
    }

    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* 横向滚动卡片 */
    .scroll-container {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
      padding-bottom: 12px;
    }

    .scroll-container::-webkit-scrollbar {
      height: 4px;
    }

    .scroll-container::-webkit-scrollbar-thumb {
      background: var(--primary);
      border-radius: 4px;
    }

    .stat-card {
      min-width: 220px;
      background: linear-gradient(135deg, #141B2D, #1A1F35);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      text-align: center;
      scroll-snap-align: start;
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }

    .stat-card:hover {
      transform: scale(1.04);
      box-shadow: 0 12px 28px rgba(0,0,0,0.5);
    }

    .stat-number {
      font-family: var(--font-mono);
      font-size: 3rem;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }

    @media (min-width: 768px) {
      .scroll-container {
        overflow-x: visible;
        flex-wrap: wrap;
        justify-content: center;
      }
      .stat-card {
        min-width: 200px;
        flex: 1 1 200px;
      }
    }

    /* 页脚 */
    .footer-link {
      color: var(--text-secondary);
      transition: color var(--transition-smooth);
    }

    .footer-link:hover {
      color: var(--primary);
    }

    /* 汉堡菜单图标 */
    .hamburger {
      display: flex;
      flex-direction: column;
      justify-content: space-around;
      width: 24px;
      height: 20px;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      display: block;
      width: 100%;
      height: 2px;
      background: var(--primary);
      transition: all 0.3s ease;
    }