/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-soft: rgba(26, 95, 122, 0.08);
      --accent: #F4A261;
      --accent-hover: #E68A3E;
      --bg: #FAFBFB;
      --card-bg: #FFFFFF;
      --border: #E9ECEF;
      --text-main: #1E293B;
      --text-strong: #0F172A;
      --text-muted: #64748B;
      --text-body: #334155;
      --success: #2A9D8F;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 6px 20px rgba(0,0,0,0.07);
      --shadow-btn: 0 2px 6px rgba(26,95,122,0.25);
      --shadow-btn-hover: 0 6px 16px rgba(26,95,122,0.35);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', 'Inter', sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      color: var(--text-main);
    }
    h1 {
      font-size: 42px;
      line-height: 1.2;
      color: var(--text-strong);
      font-weight: 700;
    }
    h2 {
      font-size: 32px;
      line-height: 1.3;
    }
    h3 {
      font-size: 22px;
      line-height: 1.4;
      font-weight: 600;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s, opacity 0.2s;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      font-weight: 600;
      transition: all 0.25s ease;
    }
    .btn-primary {
      background-color: var(--accent);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      box-shadow: var(--shadow-btn);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background-color: var(--accent-hover);
      box-shadow: var(--shadow-btn-hover);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      background: white;
      box-shadow: 0 1px 2px rgba(0,0,0,0.04);
      z-index: 50;
      padding: 16px 0;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 24px;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 18px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      color: #475569;
      font-weight: 500;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
      font-weight: 600;
    }
    .mobile-menu-btn {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--text-main);
    }
    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding: 40px 0;
      background: radial-gradient(circle at 70% 30%, rgba(26,95,122,0.05) 0%, transparent 60%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1;
      max-width: 600px;
    }
    .hero-text h1 {
      margin-bottom: 20px;
    }
    .hero-sub {
      color: var(--text-muted);
      font-size: 18px;
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-image img {
      border-radius: 24px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.08);
    }
    /* 通用板块 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      margin-bottom: 16px;
    }
    .section-subtitle {
      color: var(--text-muted);
      max-width: 700px;
      margin-bottom: 48px;
      font-size: 18px;
    }
    /* 优势卡片 非对称编号 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      padding: 32px;
      position: relative;
      box-shadow: var(--shadow-card);
      transition: all 0.25s ease;
      overflow: hidden;
    }
    .feature-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }
    .feature-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      opacity: 0.15;
      position: absolute;
      top: 20px;
      right: 24px;
      line-height: 1;
      pointer-events: none;
    }
    .feature-content {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .feature-title {
      font-weight: 700;
      font-size: 20px;
      color: var(--text-strong);
    }
    .feature-desc {
      color: var(--text-muted);
      font-size: 15px;
    }
    .metric {
      display: inline-block;
      background: rgba(42,157,143,0.08);
      color: var(--success);
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 14px;
      margin-top: 8px;
    }
    /* 产品交错 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .product-row.reverse {
      flex-direction: row-reverse;
    }
    .product-text {
      flex: 1;
    }
    .product-text h3 {
      margin-bottom: 16px;
    }
    .product-list {
      list-style: none;
    }
    .product-list li {
      display: flex;
      align-items: flex-start;
      gap: 10px;
      margin-bottom: 14px;
      color: var(--text-body);
    }
    .product-list i {
      color: var(--success);
      font-size: 18px;
      margin-top: 3px;
    }
    .product-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    /* 场景卡片 顶部色条 */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scenario-card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.25s;
    }
    .scenario-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }
    .scenario-top-bar {
      height: 4px;
      background: var(--primary);
      width: 100%;
    }
    .scenario-body {
      padding: 28px;
    }
    .scenario-body h4 {
      margin-bottom: 8px;
      font-weight: 700;
    }
    .scenario-img {
      width: 100%;
      height: 140px;
      object-fit: cover;
    }
    /* 案例网格 */
    .cases-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .case-card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-card);
    }
    .case-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 16px;
    }
    .case-company {
      font-weight: 700;
      color: var(--text-strong);
    }
    .case-tag {
      background: var(--primary-soft);
      color: var(--primary);
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      font-weight: 600;
    }
    .case-data {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      margin: 12px 0 8px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      color: var(--text-strong);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      padding: 12px 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.25s;
      color: #475569;
      padding-left: 12px;
      border-left: 0px solid transparent;
    }
    .faq-item.open .faq-answer {
      max-height: 300px;
      padding: 16px 0 16px 16px;
      border-left: 3px solid var(--primary);
    }
    .faq-icon {
      font-size: 20px;
      transition: transform 0.25s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-section {
      background: #F0F4F5;
      text-align: center;
      padding: 80px 0;
    }
    .cta-form {
      display: flex;
      justify-content: center;
      gap: 12px;
      margin-top: 28px;
      flex-wrap: wrap;
    }
    .cta-input {
      padding: 14px 20px;
      border: 1px solid #CBD5E1;
      border-radius: var(--radius-btn);
      font-size: 16px;
      width: 300px;
      max-width: 100%;
      transition: 0.2s;
      background: white;
    }
    .cta-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,122,0.15);
    }
    /* 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-col h4 {
      color: #F8FAFC;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer-col a {
      color: #94A3B8;
      display: block;
      margin-bottom: 10px;
    }
    .footer-col a:hover {
      color: var(--accent);
    }
    .copyright {
      margin-top: 40px;
      border-top: 1px solid #334155;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
      color: #94A3B8;
    }
    /* 移动端菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: white;
      box-shadow: -5px 0 15px rgba(0,0,0,0.1);
      z-index: 100;
      flex-direction: column;
      padding: 32px;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .menu-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.3);
      z-index: 99;
      display: none;
    }
    .menu-overlay.show {
      display: block;
    }
    @media (max-width: 1024px) {
      .features-grid, .scenarios-grid {
        grid-template-columns: 1fr 1fr;
      }
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-text {
        max-width: 100%;
      }
    }
    @media (max-width: 768px) {
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .features-grid, .scenarios-grid, .cases-grid {
        grid-template-columns: 1fr;
      }
      .product-row, .product-row.reverse {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .section {
        padding: 60px 0;
      }
    }