/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-light: #EEF1FE;
      --primary-soft: #DDE3FD;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E5E8EF;
      --bg-page: #F5F6FA;
      --bg-white: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 200ms ease;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --max-width: 1200px;
      --nav-height: 64px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.5;
      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);
    }

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

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--bg-white);
      height: var(--nav-height);
      box-shadow: 0 1px 0 var(--border-light);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 24px;
    }

    .nav-logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }

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

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

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

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

    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
      cursor: pointer;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .nav {
        padding: 0 16px;
      }
    }

    /* 移动端底部胶囊导航 */
    .bottom-nav {
      display: none;
      position: fixed;
      bottom: 16px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--bg-white);
      box-shadow: 0 4px 24px rgba(0,0,0,0.12);
      border-radius: 40px;
      padding: 8px 20px;
      z-index: 60;
      gap: 24px;
    }

    .bottom-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 10px;
      color: var(--text-secondary);
      font-weight: 500;
    }

    .bottom-nav a.active {
      color: var(--primary);
    }

    @media (max-width: 768px) {
      .bottom-nav {
        display: flex;
      }
      body {
        padding-bottom: 100px;
      }
      .nav-links-mobile {
        display: none;
      }
    }

    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 16px;
      transition: all var(--transition);
      cursor: pointer;
      border: none;
      background: var(--primary);
      color: white;
      line-height: 1.2;
    }

    .btn:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(78,110,242,0.3);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid #D0D5E0;
      color: var(--text-primary);
    }

    .btn-outline:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: transparent;
      box-shadow: none;
    }

    .btn:focus-visible {
      outline: 2px solid var(--primary);
      outline-offset: 2px;
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      gap: 60px;
      padding: 80px 0;
      min-height: 88vh;
      background: linear-gradient(180deg, #EEF1FE 0%, var(--bg-page) 100%);
    }

    .hero-content {
      flex: 1;
    }

    .hero h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.25;
      color: var(--text-primary);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero .subtitle {
      font-size: 17px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }

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

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

    .hero-image img {
      max-height: 420px;
      border-radius: 24px;
      box-shadow: var(--shadow-md);
    }

    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        padding: 40px 0;
        min-height: auto;
        gap: 32px;
      }
      .hero h1 {
        font-size: 32px;
      }
      .hero-image img {
        max-height: 280px;
      }
    }

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

    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-title h2 {
      font-size: 30px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 8px;
    }

    .section-title p {
      color: var(--text-secondary);
    }

    /* 卡片网格 2x3 非对称 */
    .solutions-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 24px;
    }

    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
    }

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

    .card-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 24px;
    }

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

    .card p {
      color: var(--text-secondary);
      font-size: 15px;
      line-height: 1.5;
    }

    .featured-card {
      grid-row: span 2;
    }

    @media (max-width: 768px) {
      .solutions-grid {
        grid-template-columns: 1fr;
      }
      .featured-card {
        grid-row: auto;
      }
    }

    /* 场景左右交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }

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

    .scenario-img {
      flex: 5;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .scenario-text {
      flex: 7;
    }

    .scenario-text h3 {
      font-size: 26px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .scenario-text ul {
      list-style: none;
      margin-top: 16px;
    }

    .scenario-text li {
      margin-bottom: 8px;
      display: flex;
      align-items: baseline;
      gap: 8px;
      color: var(--text-secondary);
    }

    .scenario-text li::before {
      content: "•";
      color: var(--primary);
      font-weight: bold;
    }

    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
    }

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

    .case-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    .case-logo {
      width: 48px;
      height: 48px;
      background: #F2F3F5;
      border-radius: 50%;
      margin: 0 auto 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      color: var(--text-secondary);
    }

    .case-metric {
      font-size: 34px;
      font-weight: 700;
      color: var(--primary);
    }

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

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

    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.25s ease;
      background: #FAFBFD;
      padding: 0 24px;
      color: var(--text-secondary);
      font-size: 15px;
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 16px 24px;
    }

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

    /* CTA横幅 */
    .cta-banner {
      background: var(--bg-white);
      text-align: center;
      padding: 80px 24px;
      border-radius: 24px;
      margin: 40px 0;
    }

    /* 页脚 */
    .footer {
      background: #1F2329;
      color: #86909C;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    .footer a {
      color: #86909C;
    }

    .footer a:hover {
      color: white;
    }

    .footer-bottom {
      border-top: 1px solid #2E3238;
      margin-top: 40px;
      padding-top: 20px;
      font-size: 13px;
      text-align: center;
    }

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

    .fade-in-up {
      opacity: 0;
      transform: translateY(24px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }

    .fade-in-up.visible {
      opacity: 1;
      transform: translateY(0);
    }