/* roulang page: index */
:root {
      --brand-blue: #0A84FF;
      --brand-blue-hover: #006ACC;
      --brand-green: #00D2A0;
      --brand-red: #FF3B30;
      --bg-light: #F8FAFC;
      --bg-card: #FFFFFF;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --border-light: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 4px 16px rgba(10,132,255,0.08), 0 8px 24px rgba(0,0,0,0.06);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-badge: 6px;
      --spacing-xs: 8px;
      --spacing-sm: 16px;
      --spacing-md: 24px;
      --spacing-lg: 32px;
      --spacing-xl: 48px;
      --spacing-2xl: 64px;
      --spacing-3xl: 80px;
      --spacing-4xl: 120px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-primary);
      font-size: 16px;
      line-height: 1.7;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    a {
      text-decoration: none;
      color: var(--brand-blue);
      transition: color 0.2s ease;
    }

    a:hover {
      color: var(--brand-blue-hover);
    }

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

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 16px;
      padding-right: 16px;
    }

    /* 自定义按钮 */
    .btn-brand {
      background-color: var(--brand-blue);
      color: #FFFFFF;
      border: none;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      font-size: 16px;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      box-shadow: 0 2px 8px rgba(10,132,255,0.25);
      line-height: 1.5;
    }

    .btn-brand:hover {
      background-color: var(--brand-blue-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 16px rgba(10,132,255,0.35);
      color: #FFFFFF;
    }

    .btn-outline-brand {
      background: transparent;
      border: 2px solid var(--brand-blue);
      color: var(--brand-blue);
      border-radius: var(--radius-btn);
      padding: 10px 26px;
      font-weight: 600;
      font-size: 16px;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .btn-outline-brand:hover {
      background-color: var(--brand-blue);
      color: #FFFFFF;
      transform: translateY(-1px);
    }

    .btn-lg {
      padding: 16px 40px;
      font-size: 18px;
    }

    /* 导航栏 */
    .navbar {
      background-color: #FFFFFF;
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
      padding: 12px 0;
      transition: all 0.2s;
    }

    .navbar-brand {
      font-weight: 700;
      font-size: 24px;
      color: var(--brand-blue);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .navbar-brand i {
      font-size: 28px;
      color: var(--brand-blue);
    }

    .nav-link {
      color: var(--text-secondary) !important;
      font-weight: 500;
      margin: 0 4px;
      padding: 8px 16px !important;
      border-radius: 6px;
      transition: color 0.2s, background 0.2s;
    }

    .nav-link:hover {
      color: var(--brand-blue) !important;
      background: rgba(10,132,255,0.04);
    }

    .nav-link.active {
      color: var(--brand-blue) !important;
      border-bottom: 2px solid var(--brand-blue);
      background: transparent;
    }

    .search-box {
      background: #F1F5F9;
      border-radius: 20px;
      padding: 8px 18px;
      border: 1px solid transparent;
      display: flex;
      align-items: center;
      gap: 8px;
      color: #94A3B8;
    }

    .search-box input {
      border: none;
      background: transparent;
      outline: none;
      width: 120px;
      color: var(--text-primary);
    }

    .search-box input::placeholder {
      color: #94A3B8;
    }

    .navbar-toggler {
      border: none;
      box-shadow: none;
    }

    /* Hero */
    #hero {
      background: linear-gradient(135deg, #F0F4FF 0%, #FFFFFF 100%);
      padding: 80px 0 100px;
    }

    .hero-title {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--text-primary);
      margin-bottom: 24px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
    }

    .trust-badge {
      font-size: 14px;
      color: var(--text-secondary);
      display: flex;
      align-items: center;
      gap: 8px;
      margin-top: 16px;
    }

    .hero-image-card {
      background: #FFFFFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 16px;
      overflow: hidden;
    }

    /* 区块标题 */
    .section-title {
      font-size: 36px;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--text-primary);
    }

    .section-desc {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    /* 卡片样式 */
    .feature-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: var(--spacing-lg);
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      height: 100%;
      border: none;
    }

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

    .feature-icon {
      font-size: 48px;
      color: var(--brand-green);
      margin-bottom: 20px;
    }

    .feature-title {
      font-size: 24px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .scenario-img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      background: #FFFFFF;
    }

    .case-card {
      background: #FFFFFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: all 0.25s;
      height: 100%;
    }

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

    .data-highlight {
      font-size: 44px;
      font-weight: 700;
      color: var(--brand-green);
      line-height: 1.2;
    }

    /* FAQ 手风琴重塑 */
    .accordion-button {
      background: transparent;
      box-shadow: none;
      font-weight: 600;
      font-size: 18px;
      padding: 16px 0;
      border-bottom: 1px solid var(--border-light);
      color: var(--text-primary);
    }

    .accordion-button:not(.collapsed) {
      color: var(--brand-blue);
      background: transparent;
      box-shadow: none;
    }

    .accordion-button::after {
      background-image: none;
      content: "\F282";
      font-family: "bootstrap-icons";
      font-size: 20px;
      color: #64748B;
      transition: transform 0.2s;
    }

    .accordion-button:not(.collapsed)::after {
      transform: rotate(180deg);
      color: var(--brand-blue);
    }

    .accordion-body {
      color: var(--text-secondary);
      padding: 12px 0;
    }

    .accordion-item {
      border: none;
      background: transparent;
    }

    /* CTA 区域 */
    #cta {
      background: #F0F4FF;
      padding: 80px 0;
    }

    .cta-card {
      background: #FFFFFF;
      border-radius: var(--radius-card);
      padding: 48px;
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    /* Footer */
    footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }

    footer a {
      color: #CBD5E1;
      text-decoration: none;
      transition: color 0.2s;
    }

    footer a:hover {
      color: #FFFFFF;
    }

    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: #FFFFFF;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .copyright {
      color: #94A3B8;
      font-size: 14px;
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .hero-title {
        font-size: 40px;
      }
      .section-title {
        font-size: 30px;
      }
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 32px;
      }
      .section-title {
        font-size: 26px;
      }
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
      #hero {
        padding: 40px 0 60px;
      }
    }

    @media (max-width: 576px) {
      .btn-brand, .btn-outline-brand {
        width: 100%;
        justify-content: center;
      }
    }