/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --gold: #C9A24D;
      --gold-highlight: #D4AF37;
      --deep-cyan: #1A2F3B;
      --warm-bg: #F7F5F0;
      --text-primary: #1E1E1E;
      --text-secondary: #5A5A5A;
      --card-bg: #FFFFFF;
      --border-light: #E8E4DA;
      --shadow-sm: 0 2px 12px rgba(26, 47, 59, 0.06);
      --shadow-md: 0 8px 28px rgba(26, 47, 59, 0.10);
      --radius-lg: 12px;
      --radius-md: 8px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--warm-bg);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background-color: rgba(247, 245, 240, 0.85);
      backdrop-filter: blur(12px);
      z-index: 50;
      border-bottom: 1px solid var(--border-light);
      transition: all 0.3s ease;
    }

    .nav-link {
      font-weight: 500;
      color: var(--text-primary);
      text-decoration: none;
      padding: 0.5rem 0.75rem;
      transition: color 0.2s;
      position: relative;
    }

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

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0.75rem;
      right: 0.75rem;
      height: 3px;
      background-color: var(--gold);
      border-radius: 2px;
    }

    /* 按钮体系 */
    .btn-primary {
      background-color: var(--gold);
      color: white;
      border-radius: var(--radius-md);
      padding: 0.875rem 2rem;
      font-weight: 600;
      display: inline-block;
      text-decoration: none;
      transition: all 0.25s ease;
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 10px rgba(201, 162, 77, 0.25);
    }

    .btn-primary:hover {
      background-color: var(--gold-highlight);
      transform: scale(1.02);
      box-shadow: 0 8px 18px rgba(201, 162, 77, 0.35);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--gold);
      color: var(--gold);
      border-radius: var(--radius-md);
      padding: 0.875rem 2rem;
      font-weight: 600;
      display: inline-block;
      text-decoration: none;
      transition: all 0.25s ease;
    }

    .btn-outline:hover {
      background-color: var(--gold);
      color: white;
    }

    /* 卡片样式 */
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      padding: 2rem;
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }

    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
      border-color: var(--gold);
    }

    .data-card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: 1.5rem;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }

    /* 板块标题 */
    .section-title {
      font-size: 2.25rem;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 1rem;
      color: var(--deep-cyan);
    }

    .section-subtitle {
      font-size: 1.125rem;
      color: var(--text-secondary);
      max-width: 700px;
      margin-left: auto;
      margin-right: auto;
    }

    /* 数据指标数字 */
    .metric-number {
      font-family: 'Inter', sans-serif;
      font-weight: 700;
      font-size: 2.5rem;
      color: var(--gold);
    }

    /* FAQ 折叠面板 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      font-weight: 600;
      font-size: 1.125rem;
      padding: 1.25rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text-primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-secondary);
      line-height: 1.8;
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      padding-bottom: 1.5rem;
    }

    .faq-icon {
      width: 28px;
      height: 28px;
      border: 2px solid var(--gold);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--gold);
      transition: 0.2s;
    }

    /* 表单输入 */
    .form-input {
      width: 100%;
      padding: 0.875rem 1rem;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      font-family: inherit;
      transition: border 0.2s;
      background: white;
    }

    .form-input:focus {
      outline: none;
      border-color: var(--gold);
      box-shadow: 0 0 0 3px rgba(201, 162, 77, 0.15);
    }

    /* 页脚 */
    .footer {
      background-color: var(--deep-cyan);
      color: rgba(255, 255, 255, 0.8);
      padding: 3rem 0 1.5rem;
    }

    .footer a {
      color: rgba(255, 255, 255, 0.8);
      text-decoration: none;
    }

    .footer a:hover {
      color: var(--gold-highlight);
    }

    /* 移动端汉堡菜单 */
    .mobile-menu {
      display: none;
      flex-direction: column;
      background-color: rgba(247, 245, 240, 0.98);
      backdrop-filter: blur(20px);
      position: absolute;
      top: 70px;
      left: 0;
      width: 100%;
      padding: 1.5rem;
      box-shadow: var(--shadow-md);
      border-bottom: 1px solid var(--border-light);
    }

    @media (max-width: 1023px) {
      .desktop-nav {
        display: none;
      }
      .hamburger {
        display: block;
      }
    }

    @media (min-width: 1024px) {
      .hamburger {
        display: none;
      }
      .mobile-menu {
        display: none;
      }
    }

    /* 响应式调整 */
    @media (max-width: 640px) {
      .section-title {
        font-size: 1.8rem;
      }
      .metric-number {
        font-size: 2rem;
      }
    }

    /* 占位图背景 */
    .img-placeholder {
      background-color: #e9e5db;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-secondary);
      font-size: 2rem;
    }