/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-active: #2E4BD0;
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
      --text-dark: #1F2329;
      --text-secondary: #86909C;
      --bg-light: #F5F6FA;
      --card-white: #FFFFFF;
      --border-light: #E5E8EF;
      --radius-card: 12px;
      --radius-btn: 24px;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --shadow-btn: 0 4px 12px rgba(78,110,242,0.3);
      --font-system: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --max-width: 1200px;
      --nav-height: 72px;
      --transition-base: 200ms ease;
    }

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

    html {
      scroll-behavior: smooth;
    }

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

    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

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

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

    button, input, textarea {
      font-family: inherit;
      font-size: inherit;
    }

    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      transition: box-shadow var(--transition-base);
      border-bottom: 1px solid transparent;
    }

    .site-header.scrolled {
      box-shadow: 0 1px 8px rgba(0,0,0,0.06);
      border-bottom-color: var(--border-light);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: var(--nav-height);
    }

    .logo {
      display: flex;
      align-items: center;
      font-size: 24px;
      font-weight: 700;
      color: var(--text-dark);
      letter-spacing: -0.3px;
      gap: 8px;
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 20px;
      font-weight: 700;
    }

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

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-dark);
      transition: color var(--transition-base);
      position: relative;
    }

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

    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
      transition: background var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
    }

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

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 8px;
    }

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

    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 280px;
      height: 100vh;
      background: white;
      box-shadow: -4px 0 24px rgba(0,0,0,0.08);
      transform: translateX(100%);
      transition: transform 300ms ease;
      z-index: 200;
      display: flex;
      flex-direction: column;
      padding: 24px;
      gap: 24px;
    }

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

    .mobile-menu .nav-link {
      font-size: 18px;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }

    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.3);
      z-index: 150;
      display: none;
    }

    .overlay.active {
      display: block;
    }

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

    .section-title {
      font-size: 36px;
      font-weight: 600;
      line-height: 1.3;
      color: var(--text-dark);
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }

    .section-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 48px;
      max-width: 600px;
    }

    .text-center {
      text-align: center;
    }

    .mx-auto {
      margin-left: auto;
      margin-right: auto;
    }

    /* Hero */
    #hero {
      padding: 100px 0 80px;
      background: linear-gradient(135deg, #F5F6FA 0%, #E8EAFF 100%);
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-content {
      flex: 1;
    }

    .hero-image {
      flex: 1;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }

    .hero-title {
      font-size: 52px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-dark);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-desc {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 36px;
      max-width: 480px;
    }

    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: all 250ms ease;
      border: none;
      text-align: center;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: var(--shadow-btn);
    }

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

    .btn-secondary:hover {
      border-color: var(--primary);
      color: var(--primary);
    }

    /* 痛点 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
      margin-top: 32px;
    }

    .pain-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      border-left: 4px solid var(--orange);
      transition: transform 300ms ease, box-shadow 300ms ease;
      background: #FFF9F0;
    }

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

    .pain-icon {
      font-size: 32px;
      margin-bottom: 16px;
      color: var(--orange);
    }

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

    /* 解决方案非对称 */
    .solution-wrapper {
      display: flex;
      flex-wrap: wrap;
      gap: 24px;
      margin-top: 32px;
    }

    .solution-main {
      flex: 2;
      min-width: 300px;
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 40px 32px;
      box-shadow: var(--shadow-sm);
      transition: all 300ms ease;
    }

    .solution-main:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .solution-side {
      flex: 1;
      min-width: 240px;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    .solution-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 300ms ease;
    }

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

    .solution-icon {
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
    }

    .solution-title {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 数据徽章 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 24px;
      margin-top: 40px;
    }

    .stat-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px 20px;
      text-align: center;
      box-shadow: var(--shadow-sm);
      background: linear-gradient(135deg, #ffffff 0%, #F8F9FF 100%);
    }

    .stat-number {
      font-size: 56px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 12px;
    }

    .stat-label {
      font-size: 16px;
      color: var(--text-secondary);
    }

    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 24px;
      margin-top: 32px;
    }

    .testimonial-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      position: relative;
      box-shadow: var(--shadow-sm);
    }

    .testimonial-card::before {
      content: "“";
      font-size: 120px;
      color: rgba(78,110,242,0.08);
      position: absolute;
      top: 20px;
      left: 20px;
      line-height: 1;
      font-family: serif;
    }

    .quote-text {
      font-size: 18px;
      line-height: 1.8;
      margin-bottom: 24px;
      position: relative;
      z-index: 1;
    }

    .author {
      font-size: 14px;
      color: var(--text-secondary);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 40px auto 0;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .faq-item {
      background: var(--card-white);
      border-radius: 8px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      padding: 16px 24px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: var(--card-white);
      border: none;
      width: 100%;
      text-align: left;
      transition: background var(--transition-base);
    }

    .faq-question:hover {
      background: #F5F6FA;
    }

    .faq-arrow {
      font-size: 18px;
      transition: transform 200ms ease;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 300ms ease, padding 200ms ease;
      padding: 0 24px;
    }

    .faq-item.open .faq-answer {
      max-height: 300px;
      padding: 0 24px 20px;
    }

    .faq-answer p {
      color: var(--text-dark);
      line-height: 1.7;
      font-size: 16px;
    }

    /* CTA */
    #contact {
      background: linear-gradient(135deg, #EEF1FF 0%, #F5F6FA 100%);
    }

    .cta-box {
      text-align: center;
      max-width: 600px;
      margin: 0 auto;
    }

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

    .input-capsule {
      background: #F5F6FA;
      border: 1px solid var(--border-light);
      border-radius: 24px;
      padding: 12px 20px;
      font-size: 16px;
      outline: none;
      transition: border 200ms, box-shadow 200ms;
    }

    .input-capsule:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78,110,242,0.15);
    }

    /* Footer */
    .site-footer {
      background: #1F2329;
      color: #86909C;
      padding: 40px 0;
      font-size: 14px;
    }

    .footer-grid {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 24px;
    }

    .footer-logo {
      font-size: 20px;
      font-weight: 700;
      color: white;
    }

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

    .footer-links a {
      color: #86909C;
      transition: color 200ms;
    }

    .footer-links a:hover {
      color: white;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-desc {
        max-width: 100%;
        margin-left: auto;
        margin-right: auto;
      }
      .btn-group {
        justify-content: center;
      }
      .hero-title {
        font-size: 42px;
      }
      .section-title {
        font-size: 32px;
      }
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      section {
        padding: 60px 0;
      }
      .hero-title {
        font-size: 34px;
      }
      .hero-desc {
        font-size: 16px;
      }
      .pain-grid,
      .stats-grid,
      .testimonial-grid {
        grid-template-columns: 1fr;
      }
      .solution-wrapper {
        flex-direction: column;
      }
      .container {
        padding: 0 16px;
      }
      .stat-number {
        font-size: 44px;
      }
      .btn {
        padding: 12px 24px;
        font-size: 15px;
      }
    }

    @media (max-width: 520px) {
      .hero-title {
        font-size: 30px;
      }
      .section-title {
        font-size: 26px;
      }
    }