/* roulang page: index */
:root {
      --arena-red: #E10600;
      --deep-space: #1A1A2E;
      --electric-cyan: #00F0FF;
      --ash-gray: #F8F9FA;
      --text-dark: #1A1A2E;
      --text-body: #4A4A5A;
      --text-muted: #8A8A9A;
      --card-shadow-light: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.06);
      --card-shadow-hover: 0 8px 24px rgba(0,0,0,0.12);
      --glass-bg: rgba(0,0,0,0.35);
      --glass-border: rgba(255,255,255,0.15);
      --transition-base: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      margin: 0;
      padding: 0;
      background-color: #fff;
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input {
      font-family: inherit;
    }

    .container-custom {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    @media (max-width: 768px) {
      .container-custom {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* 玻璃导航 */
    .glass-nav {
      background: rgba(0, 0, 0, 0.35);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.15);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
      transition: background 0.3s ease, box-shadow 0.3s ease;
    }

    .nav-scrolled {
      background: #0F0F1A !important;
      box-shadow: 0 8px 20px rgba(0, 0, 0, 0.5);
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }

    .nav-link {
      color: white;
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.5rem 0.25rem;
      margin: 0 0.75rem;
      position: relative;
      transition: color 0.2s;
      text-shadow: 0 1px 3px rgba(0,0,0,0.6);
    }

    .nav-link:hover {
      color: var(--electric-cyan);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--electric-cyan);
      transition: width 0.25s ease;
    }

    .nav-link:hover::after {
      width: 100%;
    }

    /* 卡片悬停 */
    .card-hover {
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-shadow-hover);
    }

    /* 按钮特效 */
    .btn-primary {
      background-color: var(--arena-red);
      color: white;
      border-radius: 8px;
      font-weight: 600;
      padding: 0.75rem 2rem;
      transition: background 0.2s, box-shadow 0.2s;
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background-color: #C80500;
      box-shadow: 0 0 18px rgba(225, 6, 0, 0.5);
    }

    .btn-outline-light {
      background: transparent;
      color: white;
      border: 1.5px solid rgba(255,255,255,0.7);
      border-radius: 8px;
      font-weight: 600;
      padding: 0.75rem 2rem;
      transition: all 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-outline-light:hover {
      background: rgba(255,255,255,0.1);
      border-color: white;
    }

    /* 数据数字字体 */
    .stat-number {
      font-family: 'DIN Alternate', 'Bebas Neue', 'PingFang SC', sans-serif;
      font-weight: 700;
      letter-spacing: 1px;
    }

    /* FAQ手风琴模拟 */
    .faq-item {
      border-bottom: 1px solid #E0E0E0;
      padding: 1.25rem 0;
    }
    .faq-question {
      font-weight: 700;
      color: var(--text-dark);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      color: var(--text-body);
      margin-top: 0.5rem;
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-marker {
      color: var(--arena-red);
      font-weight: bold;
      margin-right: 8px;
    }

    /* 汉堡菜单 */
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: #0F0F1A;
      position: absolute;
      top: 64px;
      left: 0;
      width: 100%;
      padding: 1rem 2rem;
      gap: 0.8rem;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .mobile-menu a {
      color: white;
      font-weight: 500;
    }
    #menu-toggle:checked ~ .mobile-menu {
      display: flex;
    }