/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-dark: #3A5CE0;
      --primary-light: rgba(78,110,242,0.08);
      --bg: #F5F6FA;
      --surface: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --border-light: #E5E6EB;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 24px rgba(0,0,0,0.08);
      --radius: 12px;
      --radius-btn: 8px;
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --header-height: 64px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-family);
      background: var(--bg);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    a {
      color: var(--primary);
      text-decoration: none;
      transition: color 0.2s;
    }
    a:hover {
      text-decoration: underline;
      color: var(--primary-dark);
    }
    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 按钮系统 */
    .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: none;
      background: transparent;
      text-decoration: none;
      line-height: 1.2;
      white-space: nowrap;
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 4px 12px rgba(78,110,242,0.3);
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 1px solid var(--primary);
    }
    .btn-secondary:hover {
      background: var(--primary-light);
    }
    .btn-ghost {
      background: transparent;
      color: #fff;
      border: 1px solid rgba(255,255,255,0.7);
    }
    .btn-ghost:hover {
      background: #fff;
      color: var(--primary);
      border-color: #fff;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #fff;
      height: var(--header-height);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      text-decoration: none;
    }
    .logo:hover {
      text-decoration: none;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      padding: 8px 0;
      transition: color 0.2s;
      position: relative;
      text-decoration: none;
    }
    .nav-link:hover {
      color: var(--primary);
      text-decoration: none;
    }
    .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 1px;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: #fff;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 6px 18px rgba(0,0,0,0.06);
        gap: 18px;
        align-items: flex-start;
      }
      .nav-menu.open {
        display: flex;
      }
      .mobile-toggle {
        display: block;
      }
      .header .btn-primary {
        display: none;
      }
    }
    /* 板块 */
    section {
      padding: 90px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--text);
      text-align: center;
    }
    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 48px;
      text-align: center;
    }
    /* Hero */
    .hero {
      padding-top: calc(var(--header-height) + 40px);
      padding-bottom: 60px;
      display: flex;
      align-items: center;
      min-height: 90vh;
      background: var(--bg);
      position: relative;
    }
    .hero .container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-title {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 16px;
    }
    .hero-title span {
      color: var(--primary);
    }
    .hero-desc {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 28px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      height: 400px;
      box-shadow: var(--shadow-card);
      position: relative;
    }
    @media (max-width: 992px) {
      .hero .container {
        grid-template-columns: 1fr;
      }
      .hero-image {
        height: 280px;
        order: -1;
      }
      .hero-title {
        font-size: 36px;
      }
    }
    /* 优势卡片 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .advantage-card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.2s ease;
      text-align: center;
    }
    .advantage-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }
    .advantage-icon {
      width: 72px;
      height: 72px;
      background: #F5F6FA;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
      font-size: 32px;
    }
    .advantage-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .advantage-card p {
      font-size: 14px;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--surface);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 0.2s ease;
    }
    .service-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }
    .service-img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      background: #e9ebf0;
    }
    .service-body {
      padding: 20px 20px 16px;
    }
    .service-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 6px;
    }
    .service-body p {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 12px;
    }
    .service-link {
      font-weight: 500;
      font-size: 14px;
      display: inline-block;
    }
    @media (max-width: 992px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 576px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 案例滚动 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 8px;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
    }
    .case-card {
      flex: 0 0 300px;
      scroll-snap-align: start;
      background: var(--surface);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 0.2s;
      position: relative;
    }
    .case-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }
    .case-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
      padding: 60px 16px 16px;
      color: #fff;
    }
    .case-tag {
      background: var(--success);
      color: #fff;
      padding: 2px 10px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 4px;
    }
    .case-title {
      font-weight: 600;
      font-size: 18px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--surface);
      border-radius: 8px;
      margin-bottom: 8px;
      overflow: hidden;
    }
    .faq-question {
      width: 100%;
      background: #fff;
      border: none;
      text-align: left;
      padding: 16px 20px;
      font-size: 16px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text);
    }
    .faq-answer {
      background: #F9FAFB;
      padding: 0 20px 16px;
      font-size: 15px;
      color: var(--text);
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-arrow {
      transition: transform 0.2s;
      font-size: 18px;
      color: var(--text-secondary);
    }
    .faq-item.open .faq-arrow {
      transform: rotate(180deg);
    }
    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary);
      color: #fff;
      text-align: center;
      padding: 64px 24px;
    }
    .cta-banner h2 {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .cta-banner p {
      opacity: 0.9;
      margin-bottom: 24px;
    }
    /* 页脚 */
    .footer {
      background: #F5F6FA;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer h4 {
      font-weight: 600;
      margin-bottom: 12px;
      font-size: 16px;
    }
    .footer ul {
      list-style: none;
    }
    .footer li {
      margin-bottom: 6px;
      font-size: 14px;
      color: var(--text-secondary);
    }
    .footer a {
      color: var(--text-secondary);
    }
    .footer a:hover {
      color: var(--primary);
    }
    .footer-form input, .footer-form textarea {
      width: 100%;
      padding: 12px;
      border: 1px solid var(--border-light);
      border-radius: 8px;
      margin-bottom: 10px;
      font-family: inherit;
      transition: 0.2s;
    }
    .footer-form input:focus, .footer-form textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78,110,242,0.2);
      outline: none;
    }
    .copyright {
      margin-top: 32px;
      text-align: center;
      font-size: 14px;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 工具类 */
    .text-primary { color: var(--primary); }
    .mt-2 { margin-top: 8px; }
    .mb-2 { margin-bottom: 8px; }
    .hidden-mobile { display: block; }
    @media (max-width: 768px) {
      .hidden-mobile { display: none; }
    }