diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index 7dea037..67f7e5d 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -7167,6 +7167,14 @@
           opacity 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
           var(--ext-theme-background-transition) !important;
       }
+      @supports -moz-bool-pref("userChrome.autohide.fill_urlbar") {
+        #nav-bar:not([customizing]) {
+          transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+            margin-bottom 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+            opacity 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+            var(--ext-theme-background-transition) !important;
+        }
+      }
 
       #navigator-toolbox:is(:hover, :focus-within) #nav-bar:not([customizing]) {
         transition-delay: 0s !important;
@@ -7366,7 +7374,8 @@
     @supports -moz-bool-pref("userChrome.tabbar.one_liner") {
       @supports not -moz-bool-pref("userChrome.tabbar.one_liner.responsive") {
         #nav-bar {
-          transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay);
+          transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+            var(--ext-theme-background-transition) !important;
         }
 
         #nav-bar:is(:hover, :focus-within, [urlbar-exceeds-toolbar-bounds="true"]) {
@@ -7376,7 +7385,8 @@
       @supports -moz-bool-pref("userChrome.tabbar.one_liner.responsive") {
         @media screen and (prefers-reduced-motion: no-preference) and (min-width: 1100px) {
           #nav-bar {
-            transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay);
+            transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+              var(--ext-theme-background-transition) !important;
           }
 
           #nav-bar:is(:hover, :focus-within, [urlbar-exceeds-toolbar-bounds="true"]) {
diff --git a/src/autohide/_fill_urlbar.scss b/src/autohide/_fill_urlbar.scss
index f7c51c5..6101b6b 100644
--- a/src/autohide/_fill_urlbar.scss
+++ b/src/autohide/_fill_urlbar.scss
@@ -12,7 +12,8 @@
 @include Animate {
   @include OneLiner {
     #nav-bar {
-      transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay);
+      transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+                  var(--ext-theme-background-transition) !important;
     }
     #nav-bar:is(:hover, :focus-within, [urlbar-exceeds-toolbar-bounds="true"]) {
       transition-delay: 0s !important;
diff --git a/src/autohide/_navbar.scss b/src/autohide/_navbar.scss
index b7c5f69..43a1102 100644
--- a/src/autohide/_navbar.scss
+++ b/src/autohide/_navbar.scss
@@ -15,6 +15,13 @@
     transition: margin-bottom 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
                 opacity 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
                 var(--ext-theme-background-transition) !important;
+
+    @include Option("userChrome.autohide.fill_urlbar") {
+      transition: margin-inline 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+                  margin-bottom 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+                  opacity 0.25s var(--animation-easing-function) var(--uc-autohide-toolbar-delay),
+                  var(--ext-theme-background-transition) !important;
+    }
   }
   #navigator-toolbox:is(:hover, :focus-within) #nav-bar:not([customizing]) {
     transition-delay: 0s !important;