diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index d60f410..e2fcf9e 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -173,6 +173,17 @@
   .container.infobar {
     align-items: center !important;
   }
+  /*= Inactive transparent #882 ================================================*/
+  :root[tabsintitlebar] #titlebar:-moz-window-inactive {
+    opacity: 1 !important;
+    color: color-mix(in srgb, currentColor calc(var(--inactive-titlebar-opacity, 0.75) * 100%), transparent) !important;
+    --inactive-toolbarbutton-icon-fill-opacity: calc(
+      var(--toolbarbutton-icon-fill-opacity, 1) * var(--inactive-titlebar-opacity, 0.75)
+    );
+  }
+  :root[tabsintitlebar] #titlebar:-moz-window-inactive .toolbarbutton-icon {
+    fill-opacity: var(--inactive-toolbarbutton-icon-fill-opacity, 1);
+  }
 }
 /*= OS - Compatibility =======================================================*/
 @supports -moz-bool-pref("userChrome.compatibility.os") {
@@ -13537,6 +13548,7 @@
   /*= Firefox View Border #498 =================================================*/
   /*= Menubar rounding #814 ====================================================*/
   /*= Infobar Align #858 =======================================================*/
+  /*= Inactive transparent #882 ================================================*/
 }
 @media (-moz-bool-pref: "userChrome.compatibility.theme") and (-moz-bool-pref: "userChrome.tab.connect_to_window") {
   /* TARGET: original, photon */
@@ -13656,6 +13668,18 @@
     align-items: center !important;
   }
 }
+@media (-moz-bool-pref: "userChrome.compatibility.theme") {
+  :root[tabsintitlebar] #titlebar:-moz-window-inactive {
+    opacity: 1 !important;
+    color: color-mix(in srgb, currentColor calc(var(--inactive-titlebar-opacity, 0.75) * 100%), transparent) !important;
+    --inactive-toolbarbutton-icon-fill-opacity: calc(
+      var(--toolbarbutton-icon-fill-opacity, 1) * var(--inactive-titlebar-opacity, 0.75)
+    );
+  }
+  :root[tabsintitlebar] #titlebar:-moz-window-inactive .toolbarbutton-icon {
+    fill-opacity: var(--inactive-toolbarbutton-icon-fill-opacity, 1);
+  }
+}
 /*= OS - Compatibility =======================================================*/
 @media (-moz-bool-pref: "userChrome.compatibility.os") {
   /*= Windows 10 - Top border of accent color at ESR #358 ======================*/
diff --git a/css/leptonChromeESR.css b/css/leptonChromeESR.css
index 8cc1c8b..67b4dde 100644
--- a/css/leptonChromeESR.css
+++ b/css/leptonChromeESR.css
@@ -173,6 +173,17 @@
   .container.infobar {
     align-items: center !important;
   }
+  /*= Inactive transparent #882 ================================================*/
+  :root[tabsintitlebar] #titlebar:-moz-window-inactive {
+    opacity: 1 !important;
+    color: color-mix(in srgb, currentColor calc(var(--inactive-titlebar-opacity, 0.75) * 100%), transparent) !important;
+    --inactive-toolbarbutton-icon-fill-opacity: calc(
+      var(--toolbarbutton-icon-fill-opacity, 1) * var(--inactive-titlebar-opacity, 0.75)
+    );
+  }
+  :root[tabsintitlebar] #titlebar:-moz-window-inactive .toolbarbutton-icon {
+    fill-opacity: var(--inactive-toolbarbutton-icon-fill-opacity, 1);
+  }
 }
 /*= OS - Compatibility =======================================================*/
 @supports -moz-bool-pref("userChrome.compatibility.os") {
diff --git a/src/compatibility/_theme.scss b/src/compatibility/_theme.scss
index 43a8e93..bd0d991 100644
--- a/src/compatibility/_theme.scss
+++ b/src/compatibility/_theme.scss
@@ -182,3 +182,14 @@ vbox[part="drop-indicator-bar"] > image[part="drop-indicator"] {
 .container.infobar {
   align-items: center !important;
 }
+
+/*= Inactive transparent #882 ================================================*/
+:root[tabsintitlebar] #titlebar:-moz-window-inactive {
+  opacity: 1 !important;
+  color: color-mix(in srgb, currentColor calc(var(--inactive-titlebar-opacity, 0.75) * 100%), transparent) !important;
+  --inactive-toolbarbutton-icon-fill-opacity: calc(var(--toolbarbutton-icon-fill-opacity, 1) * var(--inactive-titlebar-opacity, 0.75));
+
+  .toolbarbutton-icon {
+    fill-opacity: var(--inactive-toolbarbutton-icon-fill-opacity, 1);
+  }
+}