Also seems to work
.mx-grid table>colgroup>col{
width:unset!important;
}
.mx-grid tr>td:nth-child(2),
.mx-grid tr>th:nth-child(2){
background:linear-gradient(rgba(255,255,255,0.0),rgba(255,255,255,0.2));
width:128px!important;
}
.mx-grid tr>td:nth-child(1),
.mx-grid tr>th:nth-child(1){
background:linear-gradient(rgba(255,255,0,0.0),rgba(255,0,0,0.2));
width:128px!important;
}
Create a table with 2 colums, column 1 : 0% and column 2 : 100%;
insert a new table in column 1 containing 3 cells with a width of 9 px and in column 2 the rest?