Remove white space
If after filtering, a space appears below your filter area, then it's probably padding or margin.
If you filter for example columns, then you shouldn't add the padding or margin to your rows. Only to the columns, because this will automatically be removed. You can remove it also with that CSS:

For column filtering:

.df-area .et_pb_row {
padding: 0 !important;
margin: 0 !important;
}

For row filtering

.df-area .et_pb_column {
padding: 0 !important;
margin: 0 !important;
}