/* roulang page: index */
:root {
      --primary: #7C3AED;
      --accent: #F97316;
      --bg: #0B0B0F;
      --surface: #16161D;
      --text: #F5F3FF;
      --textsoft: #A78BFA;
      --border: #2D2D3A;
      --radius-card: 16px;
      --radius-btn: 8px;
      --shadow-card: 0 10px 25px -5px rgba(124, 58, 237, 0.2);
      --shadow-hover: 0 20px 35px -10px rgba(124, 58, 237, 0.4);
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    @media (min-width: 640px) {
      .container {
        padding-left: 2rem;
        padding-right: 2rem;
      }
    }
    /* 导航霓虹效果 */
    .nav-link {
      position: relative;
      color: var(--textsoft);
      font-weight: 500;
      padding: 0.5rem 0;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--primary);
      transition: width 0.25s ease;
      border-radius: 3px;
      box-shadow: 0 0 12px var(--primary);
    }
    .nav-link:hover {
      color: var(--text);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .nav-link.active-link {
      color: var(--accent);
      font-weight: 600;
    }
    .nav-link.active-link::after {
      width: 100%;
      background: var(--accent);
      box-shadow: 0 0 14px var(--accent);
      height: 4px;
    }
    /* 卡片样式 */
    .card-hover {
      background-color: var(--surface);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      transition: transform 0.25s ease, box-shadow 0.3s ease, border-color 0.2s;
    }
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
      box-shadow: 0 0 25px rgba(124, 58, 237, 0.35);
    }
    /* 霓虹下划线标题 */
    .section-title {
      position: relative;
      display: inline-block;
      font-weight: 700;
      font-size: 2.25rem;
      letter-spacing: -0.3px;
      margin-bottom: 2.5rem;
    }
    .section-title::after {
      content: '';
      position: absolute;
      bottom: -10px;
      left: 0;
      width: 70px;
      height: 5px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      border-radius: 4px;
      box-shadow: 0 0 14px var(--primary);
    }
    /* FAQ手风琴 */
    .faq-item {
      background-color: var(--surface);
      border-radius: 12px;
      margin-bottom: 1rem;
      border-left: 3px solid var(--primary);
      transition: background 0.2s;
    }
    .faq-item:hover {
      background-color: #1e1e28;
    }
    .faq-question {
      cursor: pointer;
      padding: 1.2rem 1.5rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      padding: 0 1.5rem;
      color: var(--textsoft);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 0 1.5rem 1.5rem 1.5rem;
    }
    .faq-icon {
      font-size: 1.2rem;
      color: var(--primary);
      transition: transform 0.3s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* 按钮 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.2s;
      display: inline-block;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: 0 0 20px rgba(124, 58, 237, 0.6);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent);
      color: var(--accent);
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.2s;
      display: inline-block;
    }
    .btn-outline:hover {
      background-color: rgba(249, 115, 22, 0.1);
      box-shadow: 0 0 15px rgba(249, 115, 22, 0.4);
    }
    .btn-cta {
      background: linear-gradient(135deg, var(--primary), var(--accent));
      color: white;
      padding: 1rem 2.5rem;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: 0.25s;
      box-shadow: 0 8px 18px rgba(124, 58, 237, 0.4);
    }
    .btn-cta:hover {
      background: linear-gradient(135deg, #8b5cf6, #fb923c);
      box-shadow: 0 12px 28px rgba(249, 115, 22, 0.5);
      transform: scale(1.02);
    }
    /* 移动端菜单简单处理 */
    @media (max-width: 1023px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
    }
    @media (min-width: 1024px) {
      .mobile-menu-btn {
        display: none;
      }
    }