Un fixed_columns can be seen behind fixed column when selecting cells

[oliverbrace]

Currently, if a user turns on fixed cells within their datatable (eg fixed_columns={"headers": True, "data": 2}, and then select a cell within one of the fixed columns they are able to see the unfixed columns behind the fixed columns.

It just seems to be related to the fact that the colour chosen for the selected cells is slightly transparent. I have just added a single line of css to force change the colour to something not transparent and it works fine (gif included below)

.cell--selected {
    background-color: #99cbf6 !important
}

The issue has also been asked at the following link:
https://community.plot.ly/t/un-fixed-columns-can-be-seen-behind-fixed-column-when-selecting-cells/35625