Vaadin TreeGrid CSS border on row-depth-x


I really like the TreeGrid component to show data on indidvidual and aggregated level. To highlight the aggregated rows, I use bold italic font style, but I would appreciate also if I could use a double border below aggregated rows (e.g. v-treegrid-row-depth-1) to show that these figures represent subtotals. The problem is, that borders on that level are not shown as they are “below” the background-color of the following row due to the translate3d function of the next row does not consider the border on v-treegrid-row-depth-1.

Any chance to fix that or a workaround how to deal with it? Thanks!

Best regards