/* roulang page: index */
:root {
      --color-primary: #1A2B5F;
      --color-primary-hover: #2E4080;
      --color-green: #00A86B;
      --color-orange: #FF8C00;
      --color-red: #E53E3E;
      --color-bg: #F5F6FA;
      --color-card: #FFFFFF;
      --color-text: #1F2329;
      --color-text-soft: #6B7280;
      --color-border: #E5E7EB;
      --color-footer: #1F2329;
      --color-bg-cta: #F0F2FA;
      --color-bg-testimonial: #FAFBFD;
      
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-pill: 50px;
      --shadow-card: 0 1px 4px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-nav: 0 1px 8px rgba(0,0,0,0.05);
      
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --max-width: 1200px;
      --nav-height: 64px;
      --section-gap: 80px;
      --section-gap-mobile: 60px;
      --container-padding: 32px;
      --container-padding-tablet: 24px;
      --container-padding-mobile: 16px;
      --transition-fast: 150ms ease-out;
      --transition-base: 200ms ease-out;
      --transition-slow: 250ms ease-out;
    }

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

    html {
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

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

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 var(--container-padding);
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: #FFFFFF;
      z-index: 1000;
      display: flex;
      align-items: center;
      box-shadow: none;
      transition: box-shadow var(--transition-base);
    }

    .nav.scrolled {
      box-shadow: var(--shadow-nav);
    }

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

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--color-primary);
      letter-spacing: 1px;
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--color-text);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition-fast), border-color var(--transition-fast);
    }

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

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      width: 24px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
      z-index: 1001;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: var(--color-primary);
      border-radius: 2px;
      transition: transform var(--transition-base), opacity var(--transition-base);
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 100%;
      height: 100vh;
      background: #FFFFFF;
      z-index: 999;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 48px;
      transform: translateX(100%);
      transition: transform var(--transition-slow);
    }

    .mobile-menu.open {
      transform: translateX(0);
    }

    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--color-text);
    }

    /* 各区块 */
    section {
      padding: var(--section-gap) 0;
    }

    .section-title {
      font-size: 32px;
      font-weight: 600;
      line-height: 1.35;
      text-align: center;
      margin-bottom: 48px;
      color: var(--color-text);
    }

    /* Hero */
    .hero {
      padding-top: calc(var(--nav-height) + 40px);
      background: #FFFFFF;
    }

    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
    }

    .hero-content {
      flex: 1;
    }

    .hero-content h1 {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--color-text);
      margin-bottom: 16px;
    }

    .hero-content p {
      font-size: 18px;
      color: var(--color-text-soft);
      line-height: 1.7;
      margin-bottom: 32px;
      max-width: 560px;
    }

    .btn-primary {
      background: var(--color-primary);
      color: #FFFFFF;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-size: 16px;
      font-weight: 600;
    }

    .btn-primary:hover {
      background: var(--color-primary-hover);
      transform: scale(1.02);
      box-shadow: 0 4px 12px rgba(26,43,95,0.15);
    }

    .hero-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      background: #f0f2f5;
    }

    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    /* 痛点卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .pain-card {
      background: var(--color-card);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: transform var(--transition-slow), box-shadow var(--transition-slow);
    }

    .pain-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }

    .icon-circle {
      width: 48px;
      height: 48px;
      background: rgba(26,43,95,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--color-primary);
      font-size: 24px;
    }

    .pain-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .pain-card p {
      color: var(--color-text-soft);
      line-height: 1.7;
    }

    /* 解决方案交替布局 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }

    .solution-row.reverse {
      flex-direction: row-reverse;
    }

    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .solution-img img {
      width: 100%;
      height: auto;
    }

    .solution-text {
      flex: 1;
    }

    .solution-text h3 {
      font-size: 24px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .solution-text p {
      color: var(--color-text-soft);
      margin-bottom: 20px;
      line-height: 1.7;
    }

    .solution-list {
      list-style: none;
    }

    .solution-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
      font-size: 15px;
      color: var(--color-text);
    }

    .solution-list li i {
      color: var(--color-green);
      font-size: 18px;
    }

    /* 数据成果 */
    .results-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .stat-item .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--color-primary);
      line-height: 1.2;
      margin-bottom: 8px;
    }

    .stat-item .stat-label {
      color: var(--color-text-soft);
      font-size: 14px;
    }

    /* 客户证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: var(--color-bg-testimonial);
      padding: 28px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }

    .testimonial-card .quote-icon {
      color: #ccc;
      font-size: 24px;
      margin-bottom: 16px;
    }

    .testimonial-card p {
      font-style: italic;
      color: var(--color-text-soft);
      margin-bottom: 24px;
      line-height: 1.7;
    }

    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .avatar {
      width: 40px;
      height: 40px;
      background: #ddd;
      border-radius: 50%;
    }

    .author-info strong {
      display: block;
      font-size: 15px;
    }

    .author-info span {
      font-size: 13px;
      color: var(--color-text-soft);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--color-border);
      padding: 20px 0;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 18px;
      cursor: pointer;
      color: var(--color-text);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height var(--transition-base);
      color: var(--color-text-soft);
      line-height: 1.7;
      margin-top: 0;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    .faq-arrow {
      transition: transform var(--transition-base);
    }

    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
    }

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

    .cta-section h2 {
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .cta-section p {
      color: var(--color-text-soft);
      margin-bottom: 32px;
    }

    .btn-pill {
      background: var(--color-primary);
      color: #FFFFFF;
      padding: 16px 40px;
      border-radius: var(--radius-pill);
      font-size: 18px;
      font-weight: 600;
    }

    .btn-pill:hover {
      background: var(--color-primary-hover);
      transform: scale(1.03);
      box-shadow: 0 4px 18px rgba(26,43,95,0.18);
    }

    /* 页脚 */
    .footer {
      background: var(--color-footer);
      color: #FFFFFF;
      padding: 32px 0;
    }

    .footer .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }

    .footer-links {
      display: flex;
      gap: 24px;
    }

    .footer-links a {
      color: #ccc;
      font-size: 14px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .container {
        padding: 0 var(--container-padding-tablet);
      }
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      .hero-content p {
        max-width: 100%;
      }
      .solution-row, .solution-row.reverse {
        flex-direction: column;
      }
      .grid-3, .testimonial-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .results-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .grid-3, .testimonial-grid {
        grid-template-columns: 1fr;
      }
      .results-grid {
        grid-template-columns: 1fr 1fr;
      }
      .section-title {
        font-size: 28px;
      }
      .hero-content h1 {
        font-size: 32px;
      }
    }

    @media (max-width: 640px) {
      .container {
        padding: 0 var(--container-padding-mobile);
      }
      section {
        padding: var(--section-gap-mobile) 0;
      }
      .footer .container {
        flex-direction: column;
        text-align: center;
      }
    }