Decrease brightness of nav buttons (#7956)

Before

<img width="536" height="50" alt="image" src="https://github.com/user-attachments/assets/799fe85b-3141-4f02-b020-ab7b06439ddc" />

After

<img width="510" height="46" alt="image" src="https://github.com/user-attachments/assets/780fa55e-e42b-4c4c-8ba9-32b877cf4ddd" />

p/themes/Origine/origine.css

@@ -315,6 +315,10 @@ a:hover .icon {
 	filter: brightness(1.1);
 }
 
+.btn.active, .btn:active {
+	filter: brightness(0.95);
+}
+
 .btn.active .icon,
 .btn:active .icon {
 	filter: brightness(1.1);

p/themes/Origine/origine.rtl.css

@@ -315,6 +315,10 @@ a:hover .icon {
 	filter: brightness(1.1);
 }
 
+.btn.active, .btn:active {
+	filter: brightness(0.95);
+}
+
 .btn.active .icon,
 .btn:active .icon {
 	filter: brightness(1.1);