Firefox

Hey all, I'm trying to remove the bar that has "REMOVE" spammed in red across it. Anyone able to provide some insight/help? Here is my current userChrome.css file

#main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar > .toolbar-items { opacity: 0; pointer-events: none; } #main-window:not([tabsintitlebar="true"]) #TabsToolbar { visibility: collapse !important; } #sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] #sidebar-header { display: none; } .tab { margin-left: 1px; margin-right: 1px; } /* Remove close button*/ .titlebar-buttonbox-container{ display:none }