In CSS, for an internal Firefox table, how to select the first column?

Question

Firefox has its own special CSS selectors for working with tables within the web browser's UI (aka the original "Chrome"). Important note: I'm not referring to tables within websites.

I am trying to select the first row in the Bookmarks/History Library window.

In userChrome.css, I currently have:

@-moz-document url(chrome://browser/content/places/places.xhtml) {

  #placeContent::-moz-tree-column(1) {
    margin-left: 10px !important;
    color: lime !important;
  }

}

But this does not work. I also tried:

@-moz-document url(chrome://browser/content/places/places.xhtml) {

  #placeContent::-moz-tree-column():first-of-type {
    margin-left: 10px !important;
    color: lime !important;
  }

}

and

@-moz-document url(chrome://browser/content/places/places.xhtml) {

  #placeContent::-moz-tree-column(1)::-moz-tree-cell-text() {
    margin-left: 10px !important;
    color: lime !important;
  }

}

and

@-moz-document url(chrome://browser/content/places/places.xhtml) {

  #placeContent td:first-child::-moz-tree-cell-text() {
    margin-left: -10px !important;
    color: lime !important;
  }

}

But these also do not work.

How can this be done?