diff --git a/skin/classic/treestyletab/square/dropshadow.css b/skin/classic/treestyletab/square/dropshadow.css
index 6e2f43a7..c8a7b1a6 100644
--- a/skin/classic/treestyletab/square/dropshadow.css
+++ b/skin/classic/treestyletab/square/dropshadow.css
@@ -27,62 +27,6 @@
 	box-shadow: 0 0.3em 0.2em rgba(0, 0, 0, 0.15);
 }
 
-/* hide new tab button by Tab Mix Plus
-	https://addons.mozilla.org/firefox/addon/1122 */
-.tabbrowser-tabs[newTabButton="false"][treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]
-  .tabs-container:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-#TabsToolbar
-  .tabbrowser-tabs[newTabButton="false"][treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-/* hide new tab button by Tab Mix Lite
-	https://addons.mozilla.org/firefox/addon/12444 */
-.tabbrowser-tabs[newTabButton="none"][treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]
-  .tabs-container:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-#TabsToolbar
-  .tabbrowser-tabs[newTabButton="none"][treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-/* hide new tab button by Tabberwocky
-	https://addons.mozilla.org/firefox/addon/14439 */
-tabbrowser[tabberwocky-hidenewtabbutton="true"]
-  .tabbrowser-tabs[treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]
-  .tabs-container:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-#TabsToolbar[tabberwocky-hidenewtabbutton="true"] /* not implemented on 1.1, so this is just a random guess... */
-  .tabbrowser-tabs[treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-/* hide new tab button by Tab Utilities
-	https://addons.mozilla.org/firefox/addon/59961 */
-.tabbrowser-tabs[newbutton="none"][treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]
-  .tabs-container:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-#TabsToolbar
-  .tabbrowser-tabs[newbutton="none"][treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-/* hide new tab button by others */
-:root[treestyletab-hide-newtab-button="true"]
-  .tabbrowser-tabs[treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]
-  .tabs-container:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button,
-:root[treestyletab-hide-newtab-button="true"]
-  #TabsToolbar
-  .tabbrowser-tabs[treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]:not([overflow="true"])
-  .tabbrowser-arrowscrollbox
-  .tabs-newtab-button {
-	-moz-box-shadow: none;
-	box-shadow: none;
-}
-
 
 .tabbrowser-tabs[treestyletab-style~="square"][treestyletab-style~="shadow"][treestyletab-mode="vertical"]:not([overflow="true"])
   .tabbrowser-arrowscrollbox,