@media (-moz-bool-pref: "theme.containerindicator.essentials") {
  #zen-essentials-container {
    .tabbrowser-tab[usercontextid]>.tab-stack>.tab-background>.tab-context-line {
      #tabbrowser-tabs[orient="vertical"] & {
        visibility: hidden;
      }
    }
  }
}

@media (-moz-bool-pref: "theme.containerindicator.pinedtabs") {
  #vertical-pinned-tabs-container {
    .tabbrowser-tab[usercontextid]>.tab-stack>.tab-background>.tab-context-line {
      visibility: hidden;
    }
  }
}

@media (-moz-bool-pref: "theme.containerindicator.normaltabs") {
  #tabbrowser-arrowscrollbox {
    .tabbrowser-tab[usercontextid]>.tab-stack>.tab-background>.tab-context-line {
      visibility: hidden;
    }
  }
}