/* roulang page: index */
:root {
      --primary: #0A2647;
      --secondary: #144272;
      --accent: #2C74B3;
      --safe-green: #0F9B8E;
      --bg-light: #F8FAFC;
      --card-bg: #FFFFFF;
      --dark-bg: #0A2647;
      --text-primary: #1E293B;
      --text-secondary: #475569;
      --text-muted: #64748B;
      --text-on-dark: #FFFFFF;
      --border: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 6px 20px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-faq: 8px;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .inter-font {
      font-family: "Inter", "Segoe UI", system-ui, sans-serif;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #FFFFFF;
      height: 68px;
      border-bottom: 1px solid var(--border);
      z-index: 999;
      box-shadow: 0 1px 6px rgba(0,0,0,0.06);
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      white-space: nowrap;
    }
    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-menu a {
      font-size: 16px;
      color: var(--text-secondary);
      font-weight: 500;
      transition: color 0.2s;
      padding: 6px 0;
    }
    .nav-menu a:hover {
      color: var(--accent);
    }
    .nav-menu a.active {
      color: var(--primary);
      font-weight: 600;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.2s;
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 68px;
        left: 0;
        width: 100%;
        background: #FFFFFF;
        flex-direction: column;
        gap: 0;
        box-shadow: 0 6px 12px rgba(0,0,0,0.05);
        border-bottom: 1px solid var(--border);
        padding: 12px 0;
      }
      .nav-menu.active {
        display: flex;
      }
      .nav-menu a {
        padding: 14px 24px;
        border-bottom: 1px solid var(--border);
        width: 100%;
      }
      .hamburger {
        display: flex;
      }
    }
    /* 通用间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    /* Hero */
    .hero {
      background-color: var(--bg-light);
      margin-top: 68px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all 0.2s ease;
      cursor: pointer;
      border: 2px solid transparent;
      text-align: center;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border-color: var(--accent);
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      color: var(--accent);
      border-color: var(--accent);
    }
    .btn-outline:hover {
      background: rgba(44, 116, 179, 0.05);
    }
    .btn-large {
      padding: 14px 36px;
      font-size: 18px;
    }
    .hero-image {
      flex: 1;
      position: relative;
    }
    .hero-image img {
      border-radius: 16px;
      box-shadow: var(--shadow-sm);
      width: 100%;
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-text h1 {
        font-size: 36px;
      }
    }
    /* 信任条 */
    .trust-bar {
      background: #FFFFFF;
      border-top: 1px solid var(--border);
      border-bottom: 1px solid var(--border);
      padding: 28px 0;
    }
    .trust-logos {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
      filter: grayscale(100%);
      opacity: 0.7;
      transition: 0.3s;
    }
    .trust-logos:hover {
      filter: grayscale(0%);
      opacity: 1;
    }
    .trust-item {
      font-weight: 600;
      color: var(--text-muted);
      font-size: 18px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    /* 卡片通用 */
    .section-title {
      font-size: 32px;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      margin-bottom: 48px;
      font-size: 17px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .card-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: 16px;
    }
    .card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .link-detail {
      color: var(--accent);
      font-weight: 500;
      margin-top: 12px;
      display: inline-block;
    }
    .link-detail:hover {
      text-decoration: underline;
    }
    @media (max-width: 1024px) {
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .grid-3 {
        grid-template-columns: 1fr;
      }
    }
    /* 数据指标 */
    .stats-block {
      background: #F1F5F9;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--accent);
      font-family: "Inter", sans-serif;
    }
    .stat-label {
      color: var(--text-secondary);
      font-size: 16px;
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    /* 流程 */
    .process-flow {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0;
      flex-wrap: wrap;
    }
    .step {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      flex: 1;
      min-width: 160px;
    }
    .step-circle {
      width: 48px;
      height: 48px;
      background: var(--secondary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      margin-bottom: 12px;
    }
    .step-line {
      width: 60px;
      height: 2px;
      background: var(--border);
      margin: 0 8px;
      align-self: center;
      display: none;
    }
    @media (min-width: 769px) {
      .step-line {
        display: block;
      }
    }
    @media (max-width: 768px) {
      .process-flow {
        flex-direction: column;
        gap: 24px;
      }
    }
    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .case-card img {
      aspect-ratio: 16/9;
      object-fit: cover;
      background: #E2E8F0;
      border-radius: 8px;
      margin-bottom: 16px;
    }
    .tag {
      background: #F1F5F9;
      color: var(--text-secondary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 14px;
      display: inline-block;
      margin-right: 8px;
    }
    @media (max-width: 768px) {
      .case-grid {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius-faq);
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: white;
      transition: 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: #F8FAFC;
      padding: 0 24px;
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 18px 24px;
      border-top: 1px solid var(--accent);
    }
    .faq-item.open {
      border-color: var(--accent);
    }
    /* CTA banner */
    .cta-banner {
      background: var(--dark-bg);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-banner h2 {
      color: white;
      font-size: 32px;
      margin-bottom: 24px;
    }
    .btn-white {
      background: white;
      color: var(--primary);
      border: none;
    }
    .btn-white:hover {
      background: #e2e8f0;
    }
    /* 页脚 */
    .footer {
      background: var(--dark-bg);
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer a {
      color: #CBD5E1;
      display: block;
      margin-bottom: 8px;
    }
    .footer a:hover {
      color: white;
    }
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    button, .btn {
      outline: none;
    }
    button:focus-visible, a:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }