/* roulang page: index */
:root {
      --primary: #1A56DB;
      --primary-dark: #1343a3;
      --secondary-dark: #0F172A;
      --accent: #F97316;
      --accent-hover: #EA580C;
      --bg-white: #FFFFFF;
      --bg-light: #F8FAFC;
      --text-body: #64748B;
      --text-dark: #1E293B;
      --border: #E2E8F0;
      --success: #10B981;
      --danger: #EF4444;
      --radius-sm: 8px;
      --radius: 12px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-hover: 0 10px 25px rgba(26,86,219,0.12), 0 4px 10px rgba(0,0,0,0.05);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "Roboto", system-ui, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-white);
      color: var(--text-body);
      font-size: 16px;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      color: var(--text-dark);
      font-weight: 700;
    }
    h1 {
      font-size: 40px;
      line-height: 1.2;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 32px;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    h3 {
      font-size: 22px;
      line-height: 1.4;
      font-weight: 600;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, input {
      font-family: inherit;
    }
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--bg-white);
      border-bottom: 1px solid var(--border);
      height: 64px;
      display: flex;
      align-items: center;
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
    }
    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 18px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-dark);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: all 0.2s;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text-dark);
      cursor: pointer;
    }
    /* 按钮系统 */
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.2s;
      box-shadow: 0 4px 10px rgba(249,115,22,0.25);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(249,115,22,0.35);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: all 0.25s;
    }
    .btn-secondary:hover {
      background: var(--primary);
      color: white;
    }
    .btn-text {
      background: none;
      border: none;
      color: var(--primary);
      font-weight: 500;
      cursor: pointer;
      padding: 8px 0;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: text-decoration 0.2s;
    }
    .btn-text:hover {
      text-decoration: underline;
    }
    /* 板块间距 */
    section {
      padding: 100px 0;
    }
    .bg-light {
      background: var(--bg-light);
    }
    /* Hero */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      margin-bottom: 20px;
    }
    .hero-subtitle {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .dashboard-preview {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
      background: rgba(248,250,252,0.9);
      backdrop-filter: blur(2px);
      padding: 20px;
      border-radius: var(--radius);
      border: 1px solid var(--border);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
    }
    .stat-card {
      background: white;
      padding: 16px;
      border-radius: var(--radius-sm);
      box-shadow: var(--shadow-card);
      text-align: center;
    }
    .stat-value {
      font-family: var(--font-number);
      font-size: 28px;
      font-weight: 700;
      color: var(--accent);
    }
    .stat-label {
      font-size: 14px;
      color: var(--text-body);
      margin-top: 4px;
    }
    /* 指标看板 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .metric-card {
      background: white;
      padding: 24px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
      text-align: center;
    }
    .metric-number {
      font-family: var(--font-number);
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
    }
    .trend-up { color: var(--success); }
    .trend-down { color: var(--danger); }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
      transition: all 0.25s;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }
    .service-img {
      height: 140px;
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-sm);
      margin-bottom: 20px;
    }
    /* 对比 */
    .comparison-dual {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      margin-top: 40px;
    }
    .compare-card {
      background: white;
      border-radius: var(--radius);
      padding: 28px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
    }
    .compare-list {
      list-style: none;
      margin-top: 20px;
    }
    .compare-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 14px;
    }
    .icon-check { color: var(--success); font-weight: bold; }
    .icon-cross { color: #94a3b8; }
    .highlight-bar {
      background: var(--bg-light);
      padding: 24px;
      border-radius: var(--radius);
      text-align: center;
      margin-top: 32px;
    }
    .big-number {
      font-family: var(--font-number);
      font-size: 44px;
      font-weight: 700;
      color: var(--accent);
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 40px auto 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 16px;
      font-weight: 600;
      color: var(--text-dark);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-body);
      padding: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    /* 表单 */
    .contact-form {
      display: flex;
      gap: 16px;
      max-width: 600px;
      margin: 32px auto 0;
      flex-wrap: wrap;
    }
    .contact-form input {
      flex: 1 1 200px;
      padding: 14px 16px;
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      font-size: 16px;
      outline: none;
    }
    .contact-form input:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,86,219,0.1);
    }
    /* 页脚 */
    .footer {
      background: var(--secondary-dark);
      color: #cbd5e1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: #94a3b8;
    }
    .footer a:hover {
      color: white;
    }
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .metrics-grid { grid-template-columns: repeat(2,1fr); }
      .services-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      h1 { font-size: 30px; }
      h2 { font-size: 26px; }
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .nav-mobile {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background: white;
        border-bottom: 1px solid var(--border);
        padding: 16px 24px;
        gap: 16px;
      }
      .metrics-grid { grid-template-columns: 1fr 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .comparison-dual { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      section { padding: 60px 0; }
    }