Wrong scroll pane border set with css

I tried to remove the scroll pane border (see attached Wanted.tiff)

First, I tried to set the -fx-border-color to transparent but this does not work.
I had to set the -fx-background-color as follows :
.scroll-pane {
    -fx-background-color: transparent;
}

Doing that, the scroll bar border at the top and bottom is removed while it shouldn't (see attached Result.tiff).