:root {
        --bg-color: #f3f4f6;
        --card-bg: #ffffff;
        --primary-accent: #4f46e5;
        --primary-hover: #4338ca;
        --text-main: #1f2937;
        --text-muted: #6b7280;
      }

      body {
        font-family: "Inter", sans-serif;
        background-color: var(--bg-color);
        color: var(--text-main);
        padding-bottom: 2rem;
      }

      /* Navbar Modernization */
      .navbar-custom {
        background-color: rgba(255, 255, 255, 0.9);
        backdrop-filter: blur(10px);
        border-bottom: 1px solid rgba(0, 0, 0, 0.05);
        position: sticky;
        top: 0;
        z-index: 1020;
      }

      /* Sleek Cards */
      .card-custom {
        background: var(--card-bg);
        border: 1px solid rgba(0, 0, 0, 0.04);
        border-radius: 16px;
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
        transition: transform 0.2s ease, box-shadow 0.2s ease;
      }
      
      .kpi-card:hover {
        transform: translateY(-3px);
        box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
      }

      /* Modern Tabs */
      .nav-pills {
        background: #e5e7eb;
        padding: 0.35rem;
        border-radius: 12px;
        display: inline-flex;
        overflow-x: auto;
        white-space: nowrap;
        flex-wrap: nowrap;
        max-width: 100%;
      }
      
      .nav-pills .nav-item {
        margin: 0;
      }

      .nav-pills .nav-link {
        color: var(--text-muted);
        font-weight: 500;
        border-radius: 8px;
        padding: 0.5rem 1.25rem;
        transition: all 0.3s ease;
      }

      .nav-pills .nav-link:hover {
        color: var(--text-main);
      }

      .nav-pills .nav-link.active {
        background-color: var(--card-bg);
        color: var(--primary-accent);
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
      }

      /* Responsive Tables */
      .table-custom {
        margin-bottom: 0;
      }
      
      .table-custom th {
        font-weight: 600;
        text-transform: uppercase;
        font-size: 0.75rem;
        letter-spacing: 0.5px;
        color: var(--text-muted);
        border-bottom: 2px solid #e5e7eb;
        background-color: transparent;
      }

      .table-custom td {
        vertical-align: middle;
        padding: 1rem 0.75rem;
        border-bottom: 1px solid #f3f4f6;
      }

      /* Form styling */
      .form-control, .form-select {
        border-radius: 10px;
        border: 1px solid #d1d5db;
        padding: 0.6rem 1rem;
      }
      
      .form-control:focus, .form-select:focus {
        border-color: var(--primary-accent);
        box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
      }

      /* Buttons */
      .btn-primary {
        background-color: var(--primary-accent);
        border-color: var(--primary-accent);
      }
      .btn-primary:hover {
        background-color: var(--primary-hover);
        border-color: var(--primary-hover);
      }

      /* Mobile Specific Hiding Rules */
      @media (max-width: 768px) {
        .hide-on-mobile {
          display: none !important;
        }
        .header-actions {
          flex-direction: column;
          align-items: stretch !important;
          gap: 1rem;
        }
        .header-actions button {
          width: 100%;
        }
      }