diff --git a/frontend/src/app/ntt-gantt/ntt-gantt.component.css b/frontend/src/app/ntt-gantt/ntt-gantt.component.css
index 499847f..9187da8 100644
--- a/frontend/src/app/ntt-gantt/ntt-gantt.component.css
+++ b/frontend/src/app/ntt-gantt/ntt-gantt.component.css
@@ -188,6 +188,7 @@
   border-radius: 8px;
   font-weight: 500;
   gap: 3px;
+  transition: background-color 0.3s ease; /* Add this line for smooth transition */
   /* box-shadow: 1px 1px 1px rgba(0, 0, 0, 0.5); */
 }