The dbc.CardBody font seems hard set to Times New Roman. Defining
.card .card-body .card-text {
font-family: Arial, Helvetica, sans-serif; !important;
}
or using an additional className setting as suggested somewhere does not change it. Defining
style={'font-family': 'Arial, Helvetica, sans-serif'}
does change it but I don’t want to have to do that with every Card definition.