/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3D5BD9;
      --success: #00B578;
      --warning: #FF9F0A;
      --danger: #FA5151;
      --text-dark: #1F2329;
      --text-secondary: #86909C;
      --bg-light: #F5F6FA;
      --bg-card: #FFFFFF;
      --border-light: #E5E8EF;
      --radius-lg: 12px;
      --radius-md: 8px;
      --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.08);
      --transition: 200ms ease-in-out;
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }

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

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button, input, textarea {
      font-family: inherit;
      font-size: inherit;
      border: none;
      outline: none;
      background: transparent;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 48px;
    }

    @media (max-width: 1024px) {
      .container {
        padding: 0 32px;
      }
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 24px;
      }
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      z-index: 100;
      transition: box-shadow var(--transition);
      height: 72px;
      display: flex;
      align-items: center;
    }

    .header.scrolled {
      box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
    }

    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-dark);
      letter-spacing: -0.5px;
    }

    .logo span {
      color: var(--primary);
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }

    .nav-menu a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-dark);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }

    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-lg);
      font-weight: 600;
      font-size: 16px;
      transition: background var(--transition), transform var(--transition);
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-1px);
    }

    .btn-secondary {
      background: transparent;
      color: var(--text-dark);
      border: 1px solid var(--border-light);
      padding: 12px 28px;
      border-radius: var(--radius-lg);
      font-weight: 600;
      font-size: 16px;
      transition: background var(--transition), border-color var(--transition), transform var(--transition);
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }

    .btn-secondary:hover {
      background: #F0F1F5;
      border-color: #ccd0d8;
      transform: translateY(-1px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 4px;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-dark);
      border-radius: 2px;
      transition: all var(--transition);
    }

    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 32px 24px;
        gap: 24px;
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 0.3s ease;
        box-shadow: 0 8px 24px rgba(0,0,0,0.05);
      }

      .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }

      .hamburger {
        display: flex;
      }
    }

    /* Hero */
    .hero {
      padding-top: 120px;
      padding-bottom: 80px;
      display: flex;
      align-items: center;
      gap: 60px;
      min-height: 90vh;
    }

    .hero-content {
      flex: 1;
    }

    .hero-content h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-dark);
      margin-bottom: 24px;
    }

    .hero-content p {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
      line-height: 1.6;
    }

    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-image {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .hero-image img {
      max-width: 100%;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-hover);
      background: #f0f2fa;
    }

    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        padding-top: 100px;
        gap: 40px;
        min-height: auto;
      }
      .hero-content h1 {
        font-size: 28px;
      }
      .hero-actions {
        flex-direction: column;
        width: 100%;
      }
      .hero-actions .btn-primary,
      .hero-actions .btn-secondary {
        width: 100%;
      }
    }

    /* 通用区块 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 48px;
      text-align: center;
      color: var(--text-dark);
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
      .section-title {
        font-size: 24px;
        margin-bottom: 32px;
      }
    }

    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .highlight-item {
      background: #F8F9FC;
      border-radius: var(--radius-lg);
      padding: 32px;
      text-align: center;
      transition: all var(--transition);
      cursor: default;
    }

    .highlight-item:hover {
      background: white;
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }

    .highlight-icon {
      font-size: 36px;
      margin-bottom: 16px;
      color: var(--primary);
    }

    .highlight-item h3 {
      font-size: 18px;
      font-weight: 600;
      color: var(--text-dark);
    }

    @media (max-width: 768px) {
      .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
      }
    }

    @media (max-width: 520px) {
      .highlights-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 服务流程 */
    .service-steps {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 40px;
    }

    .step {
      display: flex;
      gap: 32px;
      align-items: flex-start;
      position: relative;
    }

    .step-num {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1;
      min-width: 60px;
      position: relative;
    }

    .step-num::after {
      content: '';
      position: absolute;
      left: 50%;
      bottom: -28px;
      width: 2px;
      height: 40px;
      background: var(--border-light);
      transform: translateX(-50%);
    }

    .step:last-child .step-num::after {
      display: none;
    }

    .step-content h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .step-content p {
      color: var(--text-secondary);
      font-size: 16px;
    }

    @media (max-width: 768px) {
      .step {
        gap: 20px;
      }
      .step-num {
        font-size: 36px;
        min-width: 44px;
      }
      .step-num::after {
        height: 32px;
        bottom: -24px;
      }
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 24px;
    }

    .case-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }

    .case-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-hover);
    }

    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      background-color: #eef0f5;
    }

    .case-info {
      padding: 20px;
    }

    .case-tag {
      display: inline-block;
      background: rgba(78, 110, 242, 0.1);
      color: var(--primary);
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
      font-weight: 500;
    }

    .case-info h3 {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .case-desc {
      font-size: 14px;
      color: var(--text-secondary);
      opacity: 0;
      max-height: 0;
      transition: all 0.25s ease;
      overflow: hidden;
    }

    .case-card:hover .case-desc {
      opacity: 1;
      max-height: 60px;
      margin-top: 8px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: white;
      border-radius: var(--radius-lg);
      padding: 20px;
      box-shadow: var(--shadow-card);
      cursor: pointer;
      transition: box-shadow var(--transition);
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 16px;
      gap: 16px;
    }

    .faq-icon {
      font-size: 20px;
      color: var(--primary);
      transition: transform 0.2s ease;
      font-weight: 400;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, margin-top 0.2s;
      color: var(--text-dark);
      font-size: 16px;
      line-height: 1.6;
      margin-top: 0;
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }

    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    .cta-section {
      background: var(--bg-light);
      text-align: center;
    }

    .cta-inner {
      max-width: 600px;
      margin: 0 auto;
    }

    .cta-form {
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: 32px;
    }

    .cta-form input,
    .cta-form textarea {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      padding: 0 16px;
      height: 48px;
      font-size: 16px;
      transition: border 0.2s, box-shadow 0.2s;
      width: 100%;
    }

    .cta-form textarea {
      height: 120px;
      padding: 16px;
      resize: vertical;
    }

    .cta-form input:focus,
    .cta-form textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78, 110, 242, 0.1);
    }

    /* 页脚 */
    .footer {
      background: white;
      padding: 60px 0 30px;
      margin-top: 40px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-brand p {
      color: var(--text-secondary);
      margin-top: 12px;
      font-size: 14px;
    }

    .footer-col h4 {
      font-weight: 600;
      margin-bottom: 16px;
      font-size: 16px;
    }

    .footer-col a {
      display: block;
      color: var(--text-secondary);
      margin-bottom: 10px;
      font-size: 14px;
      transition: color var(--transition);
    }

    .footer-col a:hover {
      color: var(--primary);
    }

    .social-icons {
      display: flex;
      gap: 16px;
      font-size: 20px;
    }

    .copyright {
      text-align: center;
      color: var(--text-secondary);
      font-size: 14px;
      border-top: 1px solid var(--border-light);
      padding-top: 24px;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
      }
    }