/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CD9;
      --primary-light: rgba(78, 110, 242, 0.08);
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --bg-page: #F5F6FA;
      --bg-white: #FFFFFF;
      --border-light: #E8ECF0;
      --border-input: #E0E4E8;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.03);
      --shadow-card-hover: 0 6px 20px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 24px;
      --radius-tag: 4px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    img {
      max-width: 100%;
      display: block;
    }

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 40px;
    }

    /* ----- 组件样式 ----- */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 0.25s ease;
      cursor: pointer;
      border: 1px solid transparent;
      font-size: 16px;
      padding: 12px 28px;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      box-shadow: 0 2px 8px rgba(78,110,242,0.2);
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 6px 16px rgba(78,110,242,0.3);
      transform: translateY(-1px);
    }
    .btn-primary:focus-visible {
      outline: 2px solid var(--primary);
      outline-offset: 2px;
    }

    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 1px solid var(--primary);
    }
    .btn-secondary:hover {
      background-color: var(--primary-light);
    }

    .btn-white {
      background: white;
      color: var(--primary);
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    }
    .btn-white:hover {
      background: rgba(255,255,255,0.9);
      box-shadow: 0 6px 16px rgba(0,0,0,0.08);
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-light);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--primary);
      font-size: 24px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 16px;
      color: var(--text-primary);
      transition: color 0.2s;
      font-weight: 500;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-cta {
      margin-left: 16px;
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
      cursor: pointer;
    }
    /* 移动端导航抽屉 */
    .mobile-drawer {
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: white;
      flex-direction: column;
      padding: 24px;
      gap: 24px;
      display: none;
      z-index: 99;
      overflow-y: auto;
    }
    .mobile-drawer.active {
      display: flex;
    }
    .mobile-drawer a {
      font-size: 20px;
      font-weight: 500;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }

    /* 板块通用 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 16px;
      line-height: 1.4;
    }
    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    /* 卡片 */
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.25s ease;
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }

    /* Hero */
    .hero {
      padding: 120px 0 80px;
      background-color: var(--bg-white);
      background-image: radial-gradient(circle at 80% 30%, rgba(78,110,242,0.03) 0%, transparent 50%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-content h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-primary);
      margin-bottom: 20px;
    }
    .hero-content p {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      text-align: right;
    }
    .hero-image img {
      max-width: 100%;
      height: auto;
      border-radius: 16px;
      box-shadow: 0 20px 30px -15px rgba(0,0,0,0.08);
    }
    .trust-badges {
      display: flex;
      gap: 40px;
      margin-top: 48px;
      padding-top: 32px;
      border-top: 1px solid var(--border-light);
    }
    .badge-item {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .badge-number {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
    }
    .badge-label {
      font-size: 14px;
      color: var(--text-secondary);
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 16px;
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: rgba(78,110,242,0.08);
      border-radius: 12px;
    }

    /* 服务体系 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card .image-placeholder {
      aspect-ratio: 16 / 9;
      background: #F0F2F5;
      border-radius: 8px;
      overflow: hidden;
      margin-bottom: 16px;
    }
    .service-card .image-placeholder img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-link {
      color: var(--primary);
      font-weight: 600;
      margin-top: 12px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 案例 */
    .case-scroll {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-stat {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
      margin: 12px 0 8px;
    }
    .client-logo-placeholder {
      width: 40px;
      height: 40px;
      background: #E8ECF0;
      border-radius: 20px;
      margin-top: 16px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      font-weight: 600;
      padding: 16px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      transition: color 0.2s;
    }
    .faq-question i {
      transition: transform 0.25s ease;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      background: #F7F8FA;
      border-radius: 8px;
      padding: 0 20px;
      margin-bottom: 8px;
      color: #555;
      transition: all 0.3s ease;
    }
    .faq-item.active .faq-question {
      color: var(--primary);
    }
    .faq-item.active .faq-question i {
      transform: rotate(45deg);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px 20px;
    }

    /* CTA 尾板 */
    .cta-section {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-section h2 {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .cta-section p {
      font-size: 16px;
      opacity: 0.9;
      margin-bottom: 32px;
    }

    /* 页脚 */
    .footer {
      background: var(--bg-white);
      border-top: 1px solid var(--border-light);
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-col h4 {
      font-weight: 600;
      margin-bottom: 16px;
    }
    .footer-col a, .footer-col p {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 8px;
      display: block;
    }
    .footer-col a:hover {
      color: var(--primary);
    }
    .copyright {
      text-align: center;
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 32px;
      padding-top: 24px;
      border-top: 1px solid var(--border-light);
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .container { padding: 0 24px; }
      .hero-grid { flex-direction: column; gap: 32px; }
      .hero-image { text-align: center; }
      .features-grid, .services-grid, .case-scroll { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .features-grid, .services-grid, .case-scroll { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .trust-badges { flex-wrap: wrap; gap: 24px; }
    }
    @media (max-width: 576px) {
      .container { padding: 0 16px; }
      section { padding: 60px 0; }
      .hero { padding: 100px 0 60px; }
      .hero-content h1 { font-size: 28px; }
      .footer-grid { grid-template-columns: 1fr; }
    }