xpi/content/css/tab_sep_solid-inv.css
@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

@-moz-document url(chrome://browser/content/browser.xul) {
	
	#main-window[fx51plus="true"] .tabbrowser-tab::after,
	#main-window[fx51plus="true"] .tabbrowser-tab::before {
	  opacity: 0 !important;
	  border-left: 0px solid transparent !important;
	}

	#main-window #navigator-toolbox #TabsToolbar #tabbrowser-tabs[movingtab] > .tabbrowser-tab[beforeselected]:not([last-visible-tab])::after,
	#main-window #navigator-toolbox #TabsToolbar .tabbrowser-tab:not([visuallyselected]):not([afterselected-visible]):not([afterhovered]):not([first-visible-tab]):not(:hover)::before,
	#main-window #navigator-toolbox #TabsToolbar #tabbrowser-tabs:not([overflow]) > .tabbrowser-tab[last-visible-tab]:not([visuallyselected]):not([beforehovered]):not(:hover)::after,
	#main-window #navigator-toolbox #TabsToolbar .tabbrowser-tab:not([selected]):not([afterselected-visible]):not([afterhovered]):not([first-visible-tab]):not(:hover)::before,
	#main-window #navigator-toolbox #TabsToolbar #tabbrowser-tabs:not([overflow]) > .tabbrowser-tab[last-visible-tab]:not([selected]):not([beforehovered]):not(:hover)::after {
      background-image: url(chrome://classic_theme_restorer/content/images/tab-separator_solid-inv.png) !important;
	  background-size: 1px 70% !important;
      opacity:1.0 !important;
	  background-color: unset !important;
	  margin-top: 6px !important;
	  margin-bottom: 6px !important;
	  padding-top: unset !important;
	  padding-bottom: unset !important;
	}


}