diff --git a/src/pages/04_product-service/MainPage.vue b/src/pages/04_product-service/MainPage.vue
index 4c619b50..7ebe8400 100644
--- a/src/pages/04_product-service/MainPage.vue
+++ b/src/pages/04_product-service/MainPage.vue
@@ -3829,7 +3829,7 @@ watch(
               flat
               square
               :class="{
-                ' surface-3': serviceTreeView,
+                'surface-3': serviceTreeView,
                 'app-text-muted-2': serviceTreeView,
                 'app-text-muted': !serviceTreeView,
               }"