How do I style a GTK4 ColumnView's column separators with CSS?

[wooly17]

In GTK4, how would I change the color of a Gtk.ColumnView’s column separators? I’m working on a dark theme, and the column separators are bright white.

In my CSS file, I’ve tried things like columnview.column-separators separator or columnview.column-separators listview separator but I just can’t seem to hit on the correct node/class to actually change anything.

[wooly17]

After discovering the GTK Inspector today (Ctrl-Shift-D), which proved to be incredibly useful, I was able to figure this out. Here’s the CSS I added:

columnview.column-separators listview row cell:not(:first-child) {
    border-left: 1px solid shade(#3c3f41, 1.2);
}