/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --primary: #1A5F7A;
      --primary-light: #2C7A8C;
      --secondary-bg: #E8F4F8;
      --accent: #F39C12;
      --accent-hover: #E67E22;
      --text-main: #1E293B;
      --text-sub: #64748B;
      --white: #FFFFFF;
      --border: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 2px 8px rgba(26,95,122,0.12), 0 8px 24px rgba(0,0,0,0.06);
      --radius: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
      --container: 1200px;
      --header-height: 64px;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, sans-serif;
      background-color: var(--white);
      color: var(--text-main);
      line-height: 1.6;
      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);
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all var(--transition);
      border: none;
      outline: none;
    }
    
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 20px;
      width: 100%;
    }
    
    /* 导航栏 */
    header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: var(--white);
      border-bottom: 1px solid var(--border);
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
    }
    
    .logo i {
      font-size: 26px;
      color: var(--accent);
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }
    
    .nav-menu a:hover {
      color: var(--primary);
    }
    
    .nav-cta {
      margin-left: 16px;
    }
    
    .btn-primary {
      background: var(--accent);
      color: var(--white);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 4px 10px rgba(243,156,18,0.2);
    }
    
    .btn-primary:hover {
      background: var(--accent-hover);
      box-shadow: 0 6px 16px rgba(230,126,34,0.3);
      transform: translateY(-1px);
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 26px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    
    .btn-outline:hover {
      background: var(--primary);
      color: var(--white);
      border-color: var(--primary);
    }
    
    .btn-link {
      background: transparent;
      color: var(--primary);
      padding: 8px 16px;
      font-weight: 500;
      border-bottom: 1px solid transparent;
    }
    
    .btn-link:hover {
      border-bottom: 1px solid var(--primary);
    }
    
    .hamburger {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--text-main);
      cursor: pointer;
    }
    
    /* 板块通用 */
    section {
      padding: 80px 0;
    }
    
    .section-title {
      font-size: 24px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 16px;
      text-align: center;
      letter-spacing: -0.3px;
    }
    
    .section-subtitle {
      font-size: 18px;
      color: var(--text-sub);
      text-align: center;
      margin-bottom: 48px;
      max-width: 700px;
      margin-left: auto;
      margin-right: auto;
    }
    
    /* Hero */
    .hero {
      padding: 120px 0 80px;
      background: linear-gradient(180deg, #F8FAFC 0%, #FFFFFF 100%);
    }
    
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    
    .hero-text {
      flex: 1;
    }
    
    .hero-text h1 {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    
    .hero-text p {
      font-size: 18px;
      color: var(--text-sub);
      margin-bottom: 32px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 16px;
      min-height: 360px;
      box-shadow: var(--shadow-sm);
      background-color: #E8F4F8;
    }
    
    /* 核心优势卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    
    .feature-card {
      background: var(--white);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      text-align: left;
    }
    
    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    
    .feature-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 20px;
    }
    
    .feature-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    
    .feature-card p {
      color: var(--text-sub);
      font-size: 15px;
      line-height: 1.6;
    }
    
    /* 解决方案左右交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    
    .solution-content {
      flex: 1;
    }
    
    .solution-content h2 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
    }
    
    .solution-list {
      list-style: none;
      margin: 20px 0 16px;
    }
    
    .solution-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    
    .solution-list i {
      color: var(--accent);
      font-size: 18px;
      margin-top: 2px;
    }
    
    .solution-image {
      flex: 1;
      background: #E8F4F8 url('/assets/images/coverpic/cover-2.webp') center/cover no-repeat;
      border-radius: 12px;
      min-height: 280px;
      box-shadow: var(--shadow-sm);
    }
    
    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .case-card {
      background: var(--white);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    
    .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    
    .case-tag {
      display: inline-block;
      background: var(--secondary-bg);
      color: var(--primary);
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      margin-bottom: 16px;
    }
    
    .case-quote {
      font-size: 16px;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.5;
    }
    
    .case-stat {
      font-size: 28px;
      font-weight: 700;
      color: var(--accent);
      margin-bottom: 8px;
    }
    
    /* 定价 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: start;
    }
    
    .pricing-card {
      background: var(--white);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 36px 28px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: var(--transition);
      position: relative;
    }
    
    .pricing-card.recommended {
      border: 2px solid var(--accent);
      transform: scale(1.02);
    }
    
    .badge {
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--accent);
      color: white;
      padding: 6px 20px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
    }
    
    .price {
      font-size: 36px;
      font-weight: 700;
      color: var(--text-main);
      margin: 16px 0;
    }
    
    .pricing-features {
      list-style: none;
      text-align: left;
      margin: 24px 0;
    }
    
    .pricing-features li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 10px;
      color: var(--text-sub);
    }
    
    .pricing-features i {
      color: var(--accent);
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    
    .faq-item {
      margin-bottom: 16px;
      border-radius: var(--radius);
      overflow: hidden;
      background: var(--secondary-bg);
    }
    
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: var(--secondary-bg);
      color: var(--text-main);
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: var(--white);
      border-left: 3px solid var(--primary);
    }
    
    .faq-answer p {
      padding: 16px 24px;
      color: var(--text-sub);
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
    }
    
    /* CTA 横幅 */
    .cta-band {
      background: linear-gradient(135deg, #1A5F7A 0%, #2C7A8C 100%);
      color: white;
      text-align: center;
      padding: 70px 0;
    }
    
    .cta-band h2 {
      font-size: 28px;
      margin-bottom: 16px;
    }
    
    .btn-white {
      background: white;
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
    }
    
    .btn-white:hover {
      background: #f0f9ff;
    }
    
    /* 页脚 */
    footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    
    .footer-brand p {
      margin-top: 12px;
      font-size: 15px;
    }
    
    .footer-links h4, .footer-contact h4 {
      color: white;
      margin-bottom: 16px;
      font-weight: 600;
    }
    
    .footer-links ul {
      list-style: none;
    }
    
    .footer-links li {
      margin-bottom: 10px;
    }
    
    .footer-links a:hover {
      color: white;
    }
    
    .social-icons i {
      font-size: 20px;
      margin-right: 16px;
      color: #CBD5E1;
      transition: color var(--transition);
    }
    
    .social-icons i:hover {
      color: var(--accent);
    }
    
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2, 1fr); }
      .cases-grid { grid-template-columns: 1fr 1fr; }
    }
    
    @media (max-width: 768px) {
      .hamburger { display: block; }
      .nav-menu {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-menu.active { display: flex; }
      .hero-grid { flex-direction: column; }
      .hero-image { min-height: 240px; width: 100%; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .pricing-grid, .features-grid, .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }