/* roulang page: index */
:root {
      --primary: #1B1F3B;
      --primary-hover: #0F1224;
      --secondary: #A3B1C6;
      --accent: #00C9A7;
      --bg: #F5F6FA;
      --card-bg: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E0E4E8;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 24px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
      --transition: all 0.25s ease-in-out;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    button, input, textarea {
      font-family: inherit;
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: #FFFFFF;
      border-bottom: 1px solid rgba(0,0,0,0.05);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 24px;
      z-index: 1000;
      backdrop-filter: blur(10px);
      background: rgba(255,255,255,0.92);
    }
    .logo {
      font-weight: 700;
      font-size: 24px;
      letter-spacing: 1px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      color: var(--text-secondary);
      transition: var(--transition);
      font-weight: 500;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover {
      color: var(--primary);
      border-bottom-color: var(--accent);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--primary);
      cursor: pointer;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      background: linear-gradient(135deg, #1B1F3B 0%, #0D1021 100%);
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      position: relative;
      overflow: hidden;
      padding: 0 24px;
    }
    .stars {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      color: white;
    }
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-content p {
      font-size: 18px;
      color: #A3B1C6;
      margin-bottom: 40px;
      line-height: 1.6;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
      display: inline-block;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(0,0,0,0.2);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid #A3B1C6;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: var(--transition);
    }
    .btn-secondary:hover {
      background: rgba(255,255,255,0.08);
      border-color: white;
    }
    /* 通用区块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      line-height: 1.3;
      color: var(--primary);
    }
    .section-desc {
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 700px;
      margin-bottom: 48px;
    }
    /* 价值主张 - 不对称网格 */
    .value-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
    }
    .value-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      gap: 24px;
      align-items: flex-start;
    }
    .value-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .value-icon {
      font-size: 40px;
      color: var(--accent);
      flex-shrink: 0;
    }
    .value-text h3 {
      font-size: 22px;
      margin-bottom: 8px;
      font-weight: 600;
    }
    .value-text p {
      color: var(--text-secondary);
      font-size: 15px;
    }
    .value-grid .wide {
      grid-column: span 1;
    }
    /* 功能交替区 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      background: #eef0f5;
    }
    .feature-img img {
      width: 100%;
      object-fit: cover;
    }
    .feature-text {
      flex: 1;
    }
    .feature-text h3 {
      font-size: 28px;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .feature-text p {
      color: var(--text-secondary);
      font-size: 16px;
    }
    /* 场景卡片 */
    .scene-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scene-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .scene-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .scene-img {
      height: 180px;
      background: #dce1eb;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-secondary);
      font-size: 14px;
    }
    .scene-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .scene-info {
      padding: 24px;
    }
    .scene-info h4 {
      font-size: 20px;
      margin-bottom: 8px;
    }
    /* 案例区 */
    .case-slider {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 12px;
      scroll-snap-type: x mandatory;
    }
    .case-card {
      min-width: 280px;
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      scroll-snap-align: start;
      flex: 1;
    }
    .case-logo {
      width: 48px;
      height: 48px;
      background: #eef2f6;
      border-radius: 8px;
      margin-bottom: 16px;
    }
    .case-quote {
      font-style: italic;
      color: var(--text-secondary);
      margin-bottom: 12px;
    }
    .case-stat {
      font-weight: 700;
      color: var(--accent);
      font-size: 24px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
      transition: var(--transition);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      color: var(--primary);
    }
    .faq-icon {
      font-size: 22px;
      transition: transform 0.25s ease;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      padding-right: 40px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(120deg, #eef6ff 0%, #d9e9fa 100%);
      text-align: center;
      border-radius: 32px;
      margin: 0 24px;
    }
    .cta-inner {
      padding: 60px 24px;
    }
    .cta-form {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      justify-content: center;
      margin-top: 32px;
    }
    .cta-form input {
      padding: 14px 24px;
      border-radius: var(--radius-input);
      border: 1px solid var(--border-light);
      background: white;
      min-width: 220px;
      outline: none;
      transition: var(--transition);
    }
    .cta-form input:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(27,31,59,0.2);
    }
    /* 页脚 */
    .footer {
      background: var(--primary);
      color: #A3B1C6;
      padding: 60px 24px 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      max-width: 1200px;
      margin: 0 auto;
    }
    .footer-col h4 {
      color: white;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer-col a {
      display: block;
      color: #A3B1C6;
      font-size: 14px;
      margin-bottom: 8px;
      transition: var(--transition);
    }
    .footer-col a:hover {
      color: var(--accent);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .value-grid {
        grid-template-columns: 1fr;
      }
      .feature-row {
        flex-direction: column;
        gap: 32px;
      }
      .feature-row.reverse {
        flex-direction: column;
      }
      .scene-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-links.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .hero-content h1 {
        font-size: 36px;
      }
      .scene-grid {
        grid-template-columns: 1fr;
      }
      .case-slider {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }