body { background-color: #f8fafc; }
        
        .card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            transition: all 0.3s ease;
            border: 1px solid #e2e8f0;
            height: 100%;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
            border-color: #00a0e9;
        }

        .puzzle-piece {
            background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
            border: 1px dashed #00a0e9;
        }