diff --git a/content/treestyletab/treestyletab.css b/content/treestyletab/treestyletab.css
index d1959af1..62edb74a 100644
--- a/content/treestyletab/treestyletab.css
+++ b/content/treestyletab/treestyletab.css
@@ -77,16 +77,25 @@
 
 /* tab bar in the DOM-fullscreen mode */
 
-.tabbrowser-tabs[treestyletab-dom-fullscreen-activated="true"],
-.tabbrowser-strip[treestyletab-dom-fullscreen-activated="true"],
-.tabbrowser-strip[treestyletab-dom-fullscreen-activated="true"]+splitter,
-.treestyletab-tabbar-toolbar[treestyletab-dom-fullscreen-activated="true"],
-.treestyletab-tabbar-toolbar[treestyletab-dom-fullscreen-activated="true"] > *,
-tabbrowser[treestyletab-dom-fullscreen-activated="true"][tabcontainer]
+:root[inDOMFullscreen="true"]
+  .tabbrowser-tabs,
+:root[inDOMFullscreen="true"]
+  .tabbrowser-strip,
+:root[inDOMFullscreen="true"]
+  .tabbrowser-strip+splitter,
+:root[inDOMFullscreen="true"]
+  .treestyletab-tabbar-toolbar,
+:root[inDOMFullscreen="true"]
+  .treestyletab-tabbar-toolbar > *,
+:root[inDOMFullscreen="true"]
+  tabbrowser[tabcontainer]
   .tabbrowser-strip.treestyletab-tabbar-placeholder,
-tabbrowser[treestyletab-dom-fullscreen-activated="true"][tabcontainer]
-  .tabbrowser-strip.treestyletab-tabbar-placeholder+splitter {
-	visibility: collapse;
+:root[inDOMFullscreen="true"]
+  tabbrowser[tabcontainer]
+  .tabbrowser-strip.treestyletab-tabbar-placeholder+splitter,
+:root[inDOMFullscreen="true"]
+  .treestyletab-tabbar-toggler {
+	visibility: collapse !important;
 }
 
 
diff --git a/modules/browser.js b/modules/browser.js
index 8dd9d8dd..8efd51cc 100644
--- a/modules/browser.js
+++ b/modules/browser.js
@@ -5136,18 +5136,12 @@ TreeStyleTabBrowser.prototype = inherit(TreeStyleTabWindow.prototype, {
 	onBeforeFullScreenToggle : function TSTBrowser_onBeforeFullScreenToggle(aEnterFS)
 	{
 		if (this.position != 'top') {
-			// entering to the DOM-fullscreen (ex. YouTube Player)
-			if (this.document.mozFullScreen) {
-				this.setTabbrowserAttribute(this.kDOM_FULLSCREEN_ACTIVATED, true);
-			}
-			else {
-				if (this.document.documentElement.getAttribute(this.kDOM_FULLSCREEN_ACTIVATED) != 'true') {
-					if (aEnterFS)
-						this.autoHide.startForFullScreen();
-					else
-						this.autoHide.endForFullScreen();
-				}
-				this.removeTabbrowserAttribute(this.kDOM_FULLSCREEN_ACTIVATED);
+			// ignore entering to the DOM-fullscreen (ex. YouTube Player)
+			if (!this.document.mozFullScreen) {
+				if (aEnterFS)
+					this.autoHide.startForFullScreen();
+				else
+					this.autoHide.endForFullScreen();
 			}
 		}
 	},
diff --git a/modules/constants.js b/modules/constants.js
index 3f169b9c..84a042a7 100644
--- a/modules/constants.js
+++ b/modules/constants.js
@@ -82,7 +82,6 @@ var TreeStyleTabConstants = Object.freeze({
 	kFAVICONIZED        : 'treestyletab-faviconized',
 	kBG_NOTIFY_PHASE    : 'treestyletab-notifybgtab-phase',
 	kIGNORE_POPUP_STATE : 'treestyletab-ignore-state',
-	kDOM_FULLSCREEN_ACTIVATED : 'treestyletab-dom-fullscreen-activated',
 
 	kTAB_INVERTED          : 'treestyletab-tab-inverted',
 	kTAB_CONTENTS_INVERTED : 'treestyletab-tab-contents-inverted',