[help] SOLVED: unable to modify the background of pocket stories in the Firefox homepage.

Hi, i was trying to change the background of the pocket stories in the Firefox homepage with this code

@-moz-document url("about:home"), url("about:newtab"){
  div.meta{
    background-color: #08111c !important;
  }
}

yet the pocket stories are still the same default grey color.

What is wrong with my code?