/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5AD9;
      --primary-active: #2E4AC4;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      
      --bg-global: #F5F6FA;
      --bg-card: #FFFFFF;
      --bg-dark: #1F2329;
      
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --text-disabled: #C9CDD4;
      --text-white: #FFFFFF;
      
      --border: #E5E6EB;
      --radius-lg: 12px;
      --radius-md: 8px;
      --shadow-card: 0 2px 12px rgba(31, 35, 41, 0.08);
      --shadow-hover: 0 4px 20px rgba(31, 35, 41, 0.12);
      --shadow-nav: 0 1px 8px rgba(0,0,0,0.06);
      
      --font-system: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
      --nav-height: 64px;
      --nav-height-mobile: 56px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-system);
      background-color: var(--bg-global);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    @media (max-width: 576px) {
      .container {
        padding: 0 16px;
      }
    }
    
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--bg-card);
      height: var(--nav-height);
      z-index: 1000;
      transition: box-shadow 0.2s ease;
    }
    
    .header.scrolled {
      box-shadow: var(--shadow-nav);
    }
    
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-primary);
      text-decoration: none;
      letter-spacing: 0.5px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--primary);
      margin-right: 6px;
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    
    .nav-links a {
      text-decoration: none;
      color: var(--text-secondary);
      font-size: 15px;
      font-weight: 500;
      transition: color 0.15s;
      white-space: nowrap;
    }
    
    .nav-links a:hover {
      color: var(--primary);
    }
    
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-md);
      font-weight: 500;
      cursor: pointer;
      transition: all 0.2s ease;
      border: none;
      text-decoration: none;
      min-width: 44px;
      min-height: 44px;
      padding: 10px 20px;
      font-size: 15px;
      white-space: nowrap;
      background: transparent;
    }
    
    .btn-primary {
      background: var(--primary);
      color: var(--text-white);
    }
    
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(78, 110, 242, 0.3);
      transform: translateY(-1px);
    }
    
    .btn-outline {
      border: 1px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background: rgba(78, 110, 242, 0.04);
    }
    
    .btn-text {
      color: var(--primary);
      padding: 8px 12px;
      min-height: auto;
    }
    .btn-text:hover {
      text-decoration: underline;
      background: transparent;
    }
    
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
      cursor: pointer;
    }
    
    /* 移动端导航抽屉 */
    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 280px;
      height: 100vh;
      background: var(--bg-card);
      box-shadow: -4px 0 24px rgba(0,0,0,0.1);
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 1001;
      padding: 24px;
      display: flex;
      flex-direction: column;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      display: block;
      padding: 14px 0;
      font-size: 18px;
      color: var(--text-primary);
      text-decoration: none;
      border-bottom: 1px solid var(--border);
    }
    .mobile-menu .btn-primary {
      margin-top: 24px;
      text-align: center;
    }
    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.3);
      z-index: 1000;
      opacity: 0;
      visibility: hidden;
      transition: 0.3s;
    }
    .overlay.show {
      opacity: 1;
      visibility: visible;
    }
    
    @media (max-width: 992px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .header { height: var(--nav-height-mobile); }
    }
    
    /* 板块通用 */
    section {
      padding: 80px 0;
    }
    @media (max-width: 768px) {
      section { padding: 60px 0; }
    }
    
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--text-primary);
    }
    .section-title p {
      color: var(--text-secondary);
      font-size: 16px;
    }
    
    /* Hero */
    .hero {
      background: var(--bg-card);
      padding: 140px 0 80px;
      margin-top: 0;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-content h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    .hero-content .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      text-align: center;
    }
    .hero-image img {
      max-width: 100%;
      height: auto;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }
    
    @media (max-width: 768px) {
      .hero .container {
        flex-direction: column;
        gap: 40px;
      }
      .hero-content h1 {
        font-size: 28px;
      }
      .hero {
        padding: 120px 0 60px;
      }
    }
    
    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .pain-card {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      padding: 32px;
      display: flex;
      align-items: center;
      gap: 32px;
      box-shadow: var(--shadow-card);
    }
    .pain-text h3 {
      font-size: 20px;
      margin-bottom: 8px;
    }
    .pain-text p {
      color: var(--text-secondary);
      font-size: 14px;
    }
    .pain-icon {
      font-size: 40px;
      color: var(--primary);
    }
    @media (max-width: 768px) {
      .pain-grid {
        grid-template-columns: 1fr;
      }
      .pain-card {
        flex-direction: column;
        text-align: center;
      }
    }
    
    /* 解决方案卡片 */
    .solution-card {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      padding: 40px;
      text-align: center;
      max-width: 800px;
      margin: 0 auto;
      box-shadow: var(--shadow-card);
    }
    
    /* 优势网格 */
    .advantage-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .advantage-item {
      background: var(--bg-card);
      padding: 32px 20px;
      border-radius: var(--radius-lg);
      text-align: center;
      box-shadow: var(--shadow-card);
      transition: all 0.2s;
    }
    .advantage-item:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .advantage-item i {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .advantage-item h3 {
      font-size: 20px;
      margin-bottom: 8px;
    }
    @media (max-width: 992px) {
      .advantage-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 576px) {
      .advantage-grid { grid-template-columns: 1fr; }
    }
    
    /* 服务大卡片 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.2s;
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .service-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .service-body {
      padding: 24px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .service-body h3 {
      font-size: 20px;
      margin-bottom: 12px;
    }
    .feature-list {
      list-style: none;
      margin-bottom: 20px;
      flex: 1;
    }
    .feature-list li {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .feature-list i {
      color: var(--success);
    }
    @media (max-width: 992px) {
      .service-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 576px) {
      .service-grid { grid-template-columns: 1fr; }
    }
    
    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    .steps::before {
      content: '';
      position: absolute;
      top: 28px;
      left: 10%;
      right: 10%;
      height: 2px;
      background: var(--border);
      z-index: 0;
    }
    .step {
      text-align: center;
      flex: 1;
      position: relative;
      z-index: 1;
    }
    .step-circle {
      width: 56px;
      height: 56px;
      background: var(--bg-card);
      border: 2px solid var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-weight: 700;
      color: var(--primary);
      background: white;
    }
    @media (max-width: 768px) {
      .steps {
        flex-direction: column;
        gap: 32px;
      }
      .steps::before {
        display: none;
      }
    }
    
    /* 数据区 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 24px;
    }
    .stat-item h3 {
      font-size: 36px;
      color: var(--primary);
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      margin-bottom: 16px;
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-size: 16px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
      color: var(--text-secondary);
      font-size: 14px;
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      padding-bottom: 20px;
    }
    .faq-item.active .faq-question {
      color: var(--primary);
    }
    
    /* CTA */
    .cta-section {
      background: var(--bg-dark);
      color: white;
      text-align: center;
      border-radius: var(--radius-lg);
      margin: 0 24px;
      padding: 64px 24px;
    }
    @media (max-width: 576px) {
      .cta-section {
        margin: 0 16px;
      }
    }
    
    /* 页脚 */
    .footer {
      background: var(--bg-dark);
      color: var(--text-disabled);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: var(--text-disabled);
      text-decoration: none;
    }
    .footer a:hover {
      color: white;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    
    .copyright {
      border-top: 1px solid #3A3F47;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 12px;
    }