body {
            background-color: #f8f9fa;
        }
        .sidebar {
            position: fixed;
            top: 56px;
            left: 0;
            bottom: 0;
            width: 250px;
            background-color: #212529;
            padding: 20px 0;
            overflow-y: auto;
        }
        .main-content {
            margin-left: 250px;
            padding: 20px;
            margin-top: 56px;
        }
        .list-group-item {
            background-color: transparent;
            border: none;
            color: #adb5bd;
            padding: 12px 20px;
            cursor: pointer;
        }
        .list-group-item:hover {
            background-color: #343a40;
            color: white;
        }
        .list-group-item.active {
            background-color: #0d6efd;
            color: white;
        }
        .card {
            border: none;
            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
            margin-bottom: 20px;
        }
        .stat-card {
            border-left: 4px solid;
        }
        .stat-card.primary {
            border-left-color: #0d6efd;
        }
        .stat-card.success {
            border-left-color: #198754;
        }
        .stat-card.warning {
            border-left-color: #ffc107;
        }
        .stat-card.danger {
            border-left-color: #dc3545;
        }
        @media (max-width: 768px) {
            .sidebar {
                width: 100%;
                position: relative;
                top: 0;
            }
            .main-content {
                margin-left: 0;
                margin-top: 0;
            }
        }