/* roulang page: index */
:root {
      --primary: #1A3C5E;
      --secondary: #C8963E;
      --bg-light: #F5F2ED;
      --bg-dark: #0F2537;
      --text-body: #2C2C2C;
      --text-title: #1A3C5E;
      --text-muted: #5A5A5A;
      --accent-gold: #D4A843;
      --success-green: #2D6A4F;
      --card-bg: #FFFFFF;
      --card-border: #E5DFD7;
      --shadow-sm: 0 2px 16px rgba(26, 60, 94, 0.08);
      --shadow-md: 0 6px 24px rgba(26, 60, 94, 0.15);
      --nav-width: 240px;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", -apple-system, sans-serif;
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-stack);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.6;
      display: flex;
      min-height: 100vh;
    }

    /* 左侧导航 */
    .app-nav {
      width: var(--nav-width);
      background-color: var(--bg-dark);
      color: #B0C4D8;
      position: fixed;
      top: 0;
      left: 0;
      height: 100vh;
      display: flex;
      flex-direction: column;
      border-right: 1px solid var(--primary);
      z-index: 1000;
      transition: transform 0.3s ease;
    }

    .nav-logo {
      padding: 32px 24px;
      font-size: 20px;
      font-weight: 700;
      color: #FFFFFF;
      letter-spacing: 0.02em;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .nav-logo span {
      display: block;
      height: 4px;
      width: 32px;
      background: var(--secondary);
      margin-top: 8px;
      border-radius: 2px;
    }

    .nav-menu {
      flex: 1;
      padding: 24px 0;
      display: flex;
      flex-direction: column;
      gap: 4px;
    }

    .nav-item {
      color: #B0C4D8;
      text-decoration: none;
      padding: 16px 24px;
      font-size: 16px;
      font-weight: 500;
      border-left: 3px solid transparent;
      transition: all var(--transition);
      display: block;
    }

    .nav-item:hover {
      background: rgba(200, 150, 62, 0.1);
      color: #FFFFFF;
      border-left-color: var(--secondary);
    }

    .nav-item.active {
      color: #FFFFFF;
      border-left-color: var(--secondary);
      background: rgba(200, 150, 62, 0.08);
    }

    .nav-footer {
      padding: 24px;
      font-size: 12px;
      color: #6A7F94;
      border-top: 1px solid rgba(255,255,255,0.08);
    }

    /* 主内容区 */
    .main-content {
      margin-left: var(--nav-width);
      flex: 1;
      width: calc(100% - var(--nav-width));
      background: var(--bg-light);
    }

    /* 移动端顶部栏 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: var(--bg-dark);
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 999;
    }
    .mobile-logo {
      color: #FFFFFF;
      font-weight: 700;
      font-size: 18px;
    }
    .hamburger {
      background: none;
      border: none;
      display: flex;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #FFFFFF;
      border-radius: 2px;
    }

    /* 容器与排版 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 32px;
    }

    section {
      padding: 120px 0;
    }

    h2 {
      font-size: 36px;
      line-height: 44px;
      font-weight: 600;
      color: var(--text-title);
      letter-spacing: 0.01em;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-subtitle {
      text-align: center;
      color: var(--text-muted);
      font-size: 18px;
      margin-bottom: 56px;
    }

    /* 按钮 */
    .btn-primary {
      background: var(--secondary);
      color: #FFFFFF;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      display: inline-block;
      transition: background var(--transition);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--accent-gold);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      display: inline-block;
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: #FFFFFF;
    }
    .btn-large {
      padding: 18px 48px;
      font-size: 18px;
      font-weight: 700;
      border-radius: 12px;
      box-shadow: 0 4px 20px rgba(200, 150, 62, 0.4);
    }
    .text-link {
      color: var(--secondary);
      text-decoration: underline;
      font-weight: 500;
      transition: color 0.2s;
    }
    .text-link:hover {
      color: var(--accent-gold);
      text-decoration: none;
    }

    /* 卡片 */
    .card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      overflow: hidden;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .card-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .card-body {
      padding: 28px;
    }

    /* 深色面板 */
    .dark-panel {
      background: var(--bg-dark);
      color: #FFFFFF;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--secondary);
      line-height: 1.2;
    }
    .stat-label {
      color: #B0C4D8;
      font-size: 16px;
    }

    /* FAQ */
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--card-border);
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: #FFFFFF;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--text-muted);
      display: none;
    }
    .faq-item.active {
      border-color: var(--secondary);
      background: #FDFAF5;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 40px;
    }
    .footer-title {
      color: #FFFFFF;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .footer-link {
      color: #6A7F94;
      text-decoration: none;
      display: block;
      margin-bottom: 8px;
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: var(--secondary);
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .app-nav {
        transform: translateX(-100%);
      }
      .app-nav.open {
        transform: translateX(0);
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
      }
      section {
        padding: 80px 0;
      }
      h2 {
        font-size: 28px;
        line-height: 36px;
      }
      .container {
        padding: 0 20px;
      }
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }