diff --git a/.config/niri/config.kdl b/.config/niri/config.kdl
index 15a25c0a..61e6fd31 100644
--- a/.config/niri/config.kdl
+++ b/.config/niri/config.kdl
@@ -112,7 +112,7 @@ layout {
     // You can change how the focus ring looks.
     focus-ring {
         // Uncomment this line to disable the focus ring.
-        // off
+        off
 
         // How many logical pixels the ring extends out from the windows.
         width 1
@@ -148,11 +148,11 @@ layout {
     border {
         // The settings are the same as for the focus ring.
         // If you enable the border, you probably want to disable the focus ring.
-        off
+        // off
 
-        // width 4
-        // active-color "#ffc87f"
-        // inactive-color "#505050"
+        width 1
+        active-color "#B14242"
+        inactive-color "#121212"
 
         // active-gradient from="#ffbb66" to="#ffc880" angle=45 relative-to="workspace-view"
         // inactive-gradient from="#505050" to="#808080" angle=45 relative-to="workspace-view"
@@ -255,6 +255,13 @@ window-rule {
     default-column-width {}
 }
 
+window-rule {
+    match app-id=r#"firefox$"#
+    focus-ring {
+        width 4
+    }
+}
+
 // Open the Firefox picture-in-picture player as floating by default.
 window-rule {
     // This app-id regular expression will work for both: