/* roulang page: index */
:root {
      --primary: #2B5F8A;
      --primary-deep: #1E4A6E;
      --secondary: #E8A87C;
      --bg: #FAFBFD;
      --surface: #FFFFFF;
      --text-primary: #1E2D3B;
      --text-secondary: #5F6B7A;
      --border: #E8ECF1;
      --success: #3C8D6B;
      --negative: #B0BEC5;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 2px 8px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.10);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-number: "Inter", "SF Pro Display", "DIN", system-ui, sans-serif;
      --space-xs: 8px;
      --space-sm: 16px;
      --space-md: 24px;
      --space-lg: 48px;
      --space-xl: 80px;
      --header-height: 64px;
    }

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

    body {
      font-family: var(--font-sans);
      color: var(--text-primary);
      background: var(--bg);
      line-height: 1.7;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

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

    /* 页头 + 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--surface);
      z-index: 1000;
      height: var(--header-height);
      transition: box-shadow 0.2s;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
    }

    .header-shadow {
      border-bottom-color: var(--border);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
    }

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

    .brand {
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      font-weight: 700;
      font-size: 24px;
      color: var(--primary);
    }

    .brand-icon {
      display: inline-flex;
      align-items: center;
      color: var(--secondary);
      font-size: 28px;
    }

    .nav-links {
      display: flex;
      gap: var(--space-md);
      list-style: none;
      font-weight: 500;
    }

    .nav-links a {
      color: var(--text-secondary);
      text-decoration: none;
      font-size: 15px;
      padding: 4px 0;
      position: relative;
      transition: color 0.2s;
      border-bottom: 2px solid transparent;
    }

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

    .mobile-nav {
      display: none;
    }

    @media (max-width: 767px) {
      .desktop-nav {
        display: none;
      }

      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: var(--surface);
        justify-content: space-around;
        align-items: center;
        box-shadow: 0 -2px 8px rgba(0,0,0,0.06);
        height: 60px;
        z-index: 1001;
        padding-bottom: env(safe-area-inset-bottom);
      }

      .mobile-nav a {
        display: flex;
        flex-direction: column;
        align-items: center;
        font-size: 11px;
        color: var(--text-secondary);
        text-decoration: none;
        font-weight: 500;
      }

      .mobile-nav a::before {
        content: "•";
        font-size: 20px;
        margin-bottom: 2px;
      }

      body {
        padding-bottom: 80px;
      }

      .site-header {
        top: 0;
        height: 56px;
      }

      .site-header .brand {
        font-size: 20px;
      }
    }

    /* Hero */
    .hero {
      margin-top: var(--header-height);
      padding: var(--space-xl) 0;
    }

    .hero .container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-left h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
      color: var(--text-primary);
    }

    .hero-sub {
      font-size: 17px;
      color: var(--text-secondary);
      margin-bottom: 32px;
    }

    .hero-badge-group {
      display: flex;
      gap: 24px;
      margin-bottom: 32px;
      font-size: 14px;
      color: var(--primary);
      font-weight: 600;
    }

    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      text-decoration: none;
      transition: all 0.25s ease;
      cursor: pointer;
      border: 1.5px solid transparent;
      text-align: center;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
    }

    .btn-primary:hover {
      background: var(--primary-deep);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      border-color: var(--primary);
      color: var(--primary);
    }

    .btn-outline:hover {
      background: rgba(43,95,138,0.06);
    }

    .hero-right {
      aspect-ratio: 4/3;
      background: linear-gradient(135deg, #F0F4FC 0%, #E6ECF8 100%);
      border-radius: var(--radius-card);
      display: flex;
      align-items: center;
      justify-content: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      min-height: 280px;
    }

    /* 板块通用 */
    section {
      padding: var(--space-xl) 0;
    }

    .section-title h2 {
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .section-title p {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 600px;
    }

    .text-center {
      text-align: center;
    }

    .mb-48 {
      margin-bottom: var(--space-lg);
    }

    /* 指标看板 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .metric-card {
      background: var(--surface);
      padding: 36px 16px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.3s, transform 0.2s;
    }

    .metric-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }

    .metric-big {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--secondary);
    }

    .metric-label {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 8px;
    }

    /* 服务卡片 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .service-card {
      background: var(--surface);
      border-radius: var(--radius-card);
      padding: 36px 28px;
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.3s, transform 0.2s;
      display: flex;
      flex-direction: column;
    }

    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .service-img {
      width: 100%;
      aspect-ratio: 16/9;
      background-size: cover;
      background-position: center;
      border-radius: 8px;
      margin-bottom: 22px;
      background-color: #EDF2F9;
    }

    .service-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .service-card p {
      font-size: 15px;
      color: var(--text-secondary);
      margin-bottom: 18px;
    }

    .service-link {
      text-decoration: none;
      color: var(--primary);
      font-weight: 500;
      font-size: 14px;
    }
    .service-link:hover{text-decoration: underline;}

    /* 对比区 */
    .comparison-row {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      align-items: center;
      gap: 24px;
    }

    .vs-badge {
      font-size: 24px;
      font-weight: 700;
      color: white;
      background: var(--primary);
      border-radius: 50%;
      width: 54px;
      height: 54px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .pain-card, .gain-card {
      border-radius: var(--radius-card);
      padding: 32px 28px;
      background: #F5F7FA;
      border: 1px solid var(--border);
    }

    .gain-card {
      background: rgba(43,95,138,0.04);
      border-left: 3px solid var(--success);
    }

    .item-row {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 21px;
      font-size: 17px;
    }
    .legend{font-size:15px; margin-bottom:24px; font-weight:600;}
    .strike-through{color:var(--negative); text-decoration:line-through;}
    .check-icon{color:var(--success); font-weight:700;}

    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .faq-item {
      background: var(--surface);
      border-radius: var(--radius-card);
      border: 1px solid var(--border);
      overflow: hidden;
    }

    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      cursor: pointer;
      background: white;
      align-items: center;
    }

    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-secondary);
    }

    .faq-item.open .faq-answer {
      display: block;
    }

    .faq-arrow{
      transition: transform 0.3s;
    }
    .faq-item.open .faq-arrow{
      transform: rotate(180deg);
    }

    /* 表单 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      background: var(--surface);
      border-radius: var(--radius-card);
      padding: 48px 42px;
      box-shadow: var(--shadow-sm);
    }

    .form-group {
      margin-bottom: 24px;
    }

    label {
      display: block;
      font-weight: 500;
      margin-bottom: 8px;
    }

    input, textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border);
      border-radius: var(--radius-input);
      font-family: inherit;
    }

    .btn-submit {
      background: var(--secondary);
      color: white;
      font-weight: 700;
    }
    .btn-submit:hover {
      opacity: 0.9;
    }
    .contact-info p{margin-bottom:12px;}

    footer {
      background: #1E2D3B;
      color: #B0BFC9;
      padding: 50px 0;
    }

    .footer-brand {
      font-size: 24px;
      font-weight: 700;
      color: white;
    }

    @media (max-width: 1024px){
      .hero .container { grid-template-columns: 1fr; }
      .metrics-grid { grid-template-columns: repeat(2,1fr); }
      .service-grid {grid-template-columns: repeat(2,1fr);}
    }
    @media (max-width: 767px){
      .metrics-grid{grid-template-columns:1fr;}
      .service-grid{grid-template-columns:1fr;}
      .comparison-row{grid-template-columns:1fr;}
    }