/* Hide the top tabs, we usin' tree tabs on the sidebar*/
#TabsToolbar { visibility: collapse !important; }

/*Tweaks to Firefox's vertical tabs*/
#tabbrowser-tabs[orient="vertical"] {
  & .tabbrowser-tab:not([dragtarget]):not([pinned]) {
    /* Make the vertical tabs more compact */
    padding: 0 !important;
    /* Make the clickable area a little more legible*/
    border-bottom: #222 1px solid !important;
    
    & .tab-background {
      /* More compact */
      margin: 0 !important;
    }
  }
}