diff --git a/content/treestyletab/treestyletab.css b/content/treestyletab/treestyletab.css
index 6bc418b2..bae0f284 100644
--- a/content/treestyletab/treestyletab.css
+++ b/content/treestyletab/treestyletab.css
@@ -94,7 +94,13 @@
   tabbrowser[tabcontainer]
   .tabbrowser-strip.treestyletab-tabbar-placeholder+splitter,
 :root[inDOMFullscreen="true"]
-  .treestyletab-tabbar-toggler {
+  .treestyletab-tabbar-toggler,
+:root[inDOMFullscreen="true"]
+  .tabbrowser-tabs[treestyletab-mode="vertical"]
+  .tabbrowser-tab[pinned],
+:root[inDOMFullscreen="true"]
+  .tabbrowser-tabs[treestyletab-mode="vertical"]
+  .tabbrowser-tab[pinned] * /* this is required to hide unexpectedly shown gray rect (ex. .tab-background) */ {
 	visibility: collapse !important;
 }
 
@@ -611,10 +617,6 @@ toolbar.treestyletab-tabbar-toolbar-ready:not([nowindowdrag="true"]),
   .tabbrowser-tab[pinned],
 *[collapsed="true"]
   .tabbrowser-tabs[treestyletab-mode="vertical"]
-  .tabbrowser-tab[pinned] * /* this is required to hide unexpectedly shown gray rect (ex. .tab-background) */,
-.tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-dom-fullscreen-activated="true"]
-  .tabbrowser-tab[pinned],
-.tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-dom-fullscreen-activated="true"]
   .tabbrowser-tab[pinned] * /* this is required to hide unexpectedly shown gray rect (ex. .tab-background) */ {
 	visibility: collapse;
 }