/* roulang page: index */
:root {
      --primary: #0F62FE;
      --primary-dark: #0845C4;
      --primary-light: rgba(15, 98, 254, 0.1);
      --accent: #FF6B35;
      --bg-white: #FFFFFF;
      --bg-light: #F4F7FC;
      --bg-dark: #1A1A2E;
      --text-main: #1A1A2E;
      --text-secondary: #5A5A72;
      --text-footer: #B0B0C0;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(15,98,254,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --spacing-section: 100px;
      --max-width: 1200px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      color: var(--text-main);
      background: var(--bg-white);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    img {
      max-width: 100%;
      display: block;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--bg-white);
      z-index: 1000;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: 1px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-menu {
      display: flex;
      list-style: none;
      gap: 36px;
      align-items: center;
    }
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .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;
    }
    .nav-cta {
      background: var(--primary);
      color: white !important;
      padding: 10px 24px !important;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
      display: inline-block;
    }
    .nav-cta:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
      color: white !important;
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      flex-direction: column;
      gap: 5px;
      padding: 8px;
    }
    .menu-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-main);
      border-radius: 2px;
      transition: 0.2s;
    }
    /* Hero */
    .section-hero {
      padding-top: calc(var(--nav-height) + 40px);
      padding-bottom: var(--spacing-section);
      min-height: 70vh;
      display: flex;
      align-items: center;
      background: var(--bg-white);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-title {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.25;
      margin-bottom: 20px;
      color: var(--text-main);
    }
    .hero-sub {
      font-size: 18px;
      line-height: 1.6;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      align-items: center;
      gap: 20px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      display: inline-block;
      transition: background 0.2s, transform 0.2s;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      border: 1.5px solid var(--primary);
      display: inline-block;
      transition: background 0.2s;
    }
    .btn-secondary:hover {
      background: var(--primary-light);
    }
    .hero-image {
      width: 100%;
      border-radius: 16px;
      object-fit: cover;
      box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    }
    /* 通用区块 */
    .section {
      padding: var(--spacing-section) 0;
    }
    .section-bg {
      background: var(--bg-light);
    }
    .section-title {
      font-size: 32px;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--text-main);
    }
    .section-desc {
      font-size: 17px;
      color: var(--text-secondary);
      max-width: 700px;
      margin-bottom: 48px;
    }
    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .feature-card-large {
      grid-column: span 2;
      display: grid;
      grid-template-columns: 1fr 1fr;
      background: var(--bg-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: box-shadow 0.2s;
    }
    .feature-card-large:hover {
      box-shadow: var(--shadow-md);
    }
    .feature-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 28px;
      transition: box-shadow 0.2s;
    }
    .feature-card:hover {
      box-shadow: var(--shadow-md);
    }
    .feature-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      min-height: 240px;
    }
    .feature-content {
      padding: 28px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .feature-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .feature-title {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .feature-text {
      color: var(--text-secondary);
      line-height: 1.7;
    }
    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .highlight-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: box-shadow 0.2s;
    }
    .highlight-card:hover {
      box-shadow: var(--shadow-md);
    }
    .highlight-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    .highlight-label {
      color: var(--text-secondary);
      margin-top: 8px;
    }
    /* 服务方案对比 */
    .solutions-compare {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      gap: 0;
      align-items: stretch;
    }
    .solution-col {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }
    .solution-divider {
      width: 2px;
      background: var(--primary);
      opacity: 0.2;
      margin: 0 24px;
      align-self: stretch;
    }
    .solution-title {
      font-size: 24px;
      font-weight: 600;
      margin-bottom: 20px;
    }
    .solution-list {
      list-style: none;
      margin-bottom: 32px;
    }
    .solution-list li {
      position: relative;
      padding-left: 28px;
      margin-bottom: 12px;
      color: var(--text-secondary);
    }
    .solution-list li::before {
      content: '✓';
      position: absolute;
      left: 0;
      color: var(--primary);
      font-weight: bold;
    }
    /* 案例瀑布流 */
    .cases-masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: start;
    }
    .case-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.3s, transform 0.2s;
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
    }
    .case-card:hover img {
      transform: scale(1.03);
    }
    .case-img-wrap {
      overflow: hidden;
    }
    .case-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-body {
      padding: 24px;
    }
    .case-tag {
      display: inline-block;
      background: var(--bg-light);
      color: var(--primary);
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    .case-title {
      font-weight: 600;
      font-size: 18px;
      margin-bottom: 8px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.06);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      font-size: 18px;
      font-weight: 600;
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text-main);
      transition: color 0.2s;
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-icon {
      font-size: 24px;
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--text-secondary);
      line-height: 1.7;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    .faq-item.open .faq-question {
      color: var(--primary);
    }
    /* CTA 全局 */
    .cta-section {
      background: var(--bg-light);
      text-align: center;
      padding: 80px 0;
    }
    .cta-title {
      font-size: 34px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .cta-desc {
      color: var(--text-secondary);
      margin-bottom: 32px;
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 18px;
      display: inline-block;
      transition: filter 0.2s, transform 0.2s;
    }
    .btn-accent:hover {
      filter: brightness(1.1);
      transform: translateY(-2px);
    }
    /* 页脚 */
    .footer {
      background: var(--bg-dark);
      color: var(--text-footer);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
    }
    .footer-about {
      color: var(--text-footer);
      line-height: 1.7;
    }
    .footer h4 {
      color: white;
      margin-bottom: 20px;
      font-size: 16px;
    }
    .footer-links {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 12px;
    }
    .footer-links a:hover {
      color: white;
    }
    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.08);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid {
        gap: 32px;
      }
      .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .cases-masonry {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      :root {
        --spacing-section: 60px;
      }
      .nav-menu {
        display: none;
      }
      .menu-toggle {
        display: flex;
      }
      .mobile-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 20px 30px rgba(0,0,0,0.1);
        display: none;
        list-style: none;
        text-align: center;
      }
      .mobile-menu.open {
        display: flex;
      }
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero-image {
        order: -1;
        max-height: 300px;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .feature-card-large {
        grid-column: span 1;
        grid-template-columns: 1fr;
      }
      .highlights-grid {
        grid-template-columns: 1fr 1fr;
      }
      .solutions-compare {
        grid-template-columns: 1fr;
      }
      .solution-divider {
        display: none;
      }
      .cases-masonry {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }