/* roulang page: index */
:root {
      --primary-deep: #0A4C5C;
      --primary-hover: #073845;
      --accent-coral: #F85C4E;
      --bg-mist: #F4F6F8;
      --bg-light-card: #ECF0F2;
      --text-deep: #1B2A38;
      --text-soft: rgba(27, 42, 56, 0.6);
      --text-body: rgba(27, 42, 56, 0.85);
      --border-light: rgba(10, 76, 92, 0.08);
      --shadow-sm: 0 1px 3px rgba(10,76,92,0.06), 0 4px 12px rgba(10,76,92,0.04);
      --shadow-hover: 0 2px 8px rgba(10,76,92,0.10), 0 8px 24px rgba(10,76,92,0.06);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-badge: 6px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-mono: "Inter", "SF Pro Text", system-ui, sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-mist);
      color: var(--text-body);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    .font-mono, .metric-number, .data-number {
      font-family: var(--font-mono);
      font-feature-settings: "tnum";
      letter-spacing: -0.02em;
    }
    .container-main {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 1024px) {
      .container-main {
        padding-left: 20px;
        padding-right: 20px;
      }
    }
    @media (max-width: 768px) {
      .container-main {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(8px);
      box-shadow: 0 1px 2px rgba(0,0,0,0.02);
      z-index: 50;
      border-bottom: 1px solid var(--border-light);
    }
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: rgba(27,42,56,0.8);
      text-decoration: none;
      padding-bottom: 4px;
      border-bottom: 2px solid transparent;
      transition: all 0.2s ease;
    }
    .nav-link:hover {
      color: var(--primary-deep);
      border-bottom-color: var(--primary-deep);
    }
    .search-box {
      background: #f1f4f6;
      border-radius: 8px;
      padding: 6px 14px;
      display: flex;
      align-items: center;
      gap: 8px;
      width: 180px;
      border: 1px solid transparent;
      transition: 0.2s;
    }
    .search-box i {
      color: var(--text-soft);
      font-size: 14px;
    }
    .search-box input {
      border: none;
      background: transparent;
      outline: none;
      font-size: 14px;
      width: 100%;
      color: var(--text-deep);
    }
    .search-box:focus-within {
      border-color: var(--primary-deep);
      background: white;
    }
    .btn-primary {
      background: var(--primary-deep);
      color: white;
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s ease;
      border: none;
      cursor: pointer;
      font-size: 15px;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-deep);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: all 0.2s ease;
    }
    .btn-outline:hover {
      background: rgba(10,76,92,0.04);
      border-color: var(--primary-hover);
    }
    .card {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      padding: 24px;
      transition: box-shadow 0.2s ease;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
    }
    .metric-card {
      background: var(--bg-light-card);
      border-radius: var(--radius-card);
      padding: 20px;
    }
    .accent-text {
      color: var(--accent-coral);
      font-weight: 700;
    }
    .section-spacing {
      margin-top: 96px;
      margin-bottom: 96px;
    }
    @media (max-width: 1024px) {
      .section-spacing {
        margin-top: 72px;
        margin-bottom: 72px;
      }
    }
    @media (max-width: 768px) {
      .section-spacing {
        margin-top: 56px;
        margin-bottom: 56px;
      }
    }
    .h2-title {
      font-size: 30px;
      font-weight: 700;
      color: var(--text-deep);
      margin-bottom: 16px;
    }
    @media (max-width: 640px) {
      .h2-title {
        font-size: 26px;
      }
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-deep);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-body);
      font-weight: 400;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-item.active .faq-icon {
      color: var(--accent-coral);
    }
    footer {
      background: #1B2A38;
      color: rgba(255,255,255,0.7);
      padding: 48px 0 24px;
    }
    footer a {
      color: rgba(255,255,255,0.7);
      text-decoration: none;
    }
    footer a:hover {
      color: white;
    }