/* roulang page: index */
/* ----- 设计变量 & 全局重置 ----- */
    :root {
      --primary-blue: #1A6B8A;
      --primary-blue-hover: #0F4D63;
      --accent-orange: #E87722;
      --accent-orange-hover: #D0651A;
      --bg-page: #FAFBFD;
      --bg-white: #FFFFFF;
      --bg-dark: #0F2B38;
      --bg-darker: #091E28;
      --bg-contrast: #F0F3F6;
      --text-heading: #0D1B2A;
      --text-body: #3A4A5A;
      --text-muted: #6B7B8B;
      --text-white: #FFFFFF;
      --border-light: #E8ECF1;
      --border-input: #D1D9E0;
      --shadow-card: 0 2px 12px rgba(13,27,42,0.06);
      --shadow-card-hover: 0 8px 24px rgba(13,27,42,0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      --transition-fast: 0.2s ease;
      --transition-smooth: 0.3s ease;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-fast);
    }

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* ----- 导航栏 (极简高端文字导航) ----- */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      height: 70px;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--text-heading);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--primary-blue);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 38px;
    }

    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition-fast);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-blue);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 3px;
      background-color: var(--accent-orange);
      border-radius: 3px;
      transition: width var(--transition-smooth);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 70%;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--text-heading);
      cursor: pointer;
      line-height: 1;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: center;
        gap: 28px;
        padding: 40px 20px;
        border-bottom: 1px solid var(--border-light);
        transform: translateY(-120%);
        transition: transform 0.35s ease;
        box-shadow: 0 10px 20px rgba(0,0,0,0.04);
        z-index: 999;
      }
      .nav-links.active-mobile {
        transform: translateY(0);
      }
      .menu-toggle {
        display: block;
      }
    }

    /* ----- 通用区块 ----- */
    .section {
      padding: 100px 0;
    }

    @media (max-width: 640px) {
      .section {
        padding: 70px 0;
      }
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      min-height: 85vh;
      display: flex;
      align-items: center;
      padding-top: 90px;
      background: linear-gradient(180deg, #FFFFFF 0%, var(--bg-page) 100%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 50%;
    }
    .hero-title {
      font-size: clamp(2.4rem, 5vw, 3.4rem);
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-heading);
      letter-spacing: -0.5px;
    }
    .hero-sub {
      font-size: 1.1rem;
      color: var(--text-muted);
      margin: 1.2rem 0 2rem;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: all var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--accent-orange-hover);
      transform: translateY(-1px);
      box-shadow: 0 4px 14px rgba(232,119,34,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-blue);
      color: var(--primary-blue);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: all var(--transition-smooth);
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--primary-blue);
      color: white;
    }
    .hero-visual {
      flex: 1 1 45%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 28px;
      min-height: 320px;
      box-shadow: 0 20px 35px rgba(13,27,42,0.08);
      display: flex;
      align-items: flex-end;
      padding: 24px;
    }
    .kpi-panel {
      display: flex;
      gap: 24px;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(8px);
      border-radius: 16px;
      padding: 20px 24px;
      width: 100%;
      justify-content: space-around;
      flex-wrap: wrap;
    }
    .kpi-item {
      text-align: center;
    }
    .kpi-number {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary-blue);
      line-height: 1.2;
    }
    .kpi-label {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-visual {
        width: 100%;
        min-height: 260px;
      }
    }

    /* 指标看板 #metrics */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .metric-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: all var(--transition-smooth);
    }
    .metric-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .metric-value {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary-blue);
    }
    .metric-unit {
      font-size: 1.2rem;
      font-weight: 500;
    }
    .metric-desc {
      color: var(--text-muted);
      margin-top: 8px;
    }

    /* 服务矩阵 #services */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .service-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 25px;
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-card);
      transition: all var(--transition-smooth);
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      border-color: var(--primary-blue);
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-5px);
    }
    .service-icon {
      font-size: 2.2rem;
      color: var(--primary-blue);
      margin-bottom: 20px;
    }
    .service-title {
      font-size: 1.4rem;
      font-weight: 600;
      color: var(--text-heading);
      margin-bottom: 12px;
    }
    .service-desc {
      color: var(--text-body);
      margin-bottom: 18px;
      flex:1;
    }
    .text-link {
      color: var(--primary-blue);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: color var(--transition-fast);
    }
    .text-link:hover {
      color: var(--primary-blue-hover);
    }

    /* 对比 #compare */
    .compare-row {
      display: flex;
      gap: 30px;
      flex-wrap: wrap;
    }
    .compare-col {
      flex:1;
      border-radius: var(--radius-card);
      padding: 36px 28px;
    }
    .compare-old {
      background: #F0F3F6;
    }
    .compare-new {
      background: #E5F0F6;
      border: 1px solid var(--primary-blue);
    }
    .compare-title {
      font-weight: 700;
      font-size: 1.3rem;
      margin-bottom: 20px;
    }
    .compare-list {
      list-style: none;
    }
    .compare-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    /* FAQ */
    .faq-item {
      background: var(--bg-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      overflow: hidden;
      transition: all var(--transition-smooth);
    }
    .faq-question {
      padding: 22px 28px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease;
      background: #F8FAFB;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 0 28px 22px;
    }
    .faq-icon {
      font-size: 1.3rem;
      color: var(--primary-blue);
    }

    /* CTA 转化 #contact */
    .cta-section {
      background: var(--bg-dark);
      color: white;
      border-radius: 0;
    }
    .cta-inner {
      display: flex;
      gap: 50px;
      align-items: center;
      flex-wrap: wrap;
    }
    .cta-text {
      flex:1;
    }
    .cta-form {
      flex:1;
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(6px);
      border-radius: 18px;
      padding: 32px;
    }
    .form-input {
      width: 100%;
      padding: 14px 16px;
      border: 1px solid var(--border-input);
      border-radius: var(--radius-input);
      font-size: 1rem;
      margin-bottom: 16px;
      background: white;
    }
    .form-input:focus {
      border-color: var(--primary-blue);
      outline: none;
      box-shadow: 0 0 0 3px rgba(26,107,138,0.15);
    }

    /* 页脚 */
    .footer {
      background: #0F2B38;
      color: #B0C4D0;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
    }
    .copyright {
      background: #091E28;
      text-align: center;
      padding: 18px;
      color: #6B7B8B;
      margin-top: 40px;
    }

    @media (max-width: 768px) {
      .metrics-grid, .services-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .compare-row {
        flex-direction: column;
      }
    }