diff --git a/drawer.css b/drawer.css
index 478782a..12960c0 100644
--- a/drawer.css
+++ b/drawer.css
@@ -1,5 +1,5 @@
 window {
-    background-color: rgba (36, 47, 79, 0.95);
+    background-color: rgba(36, 47, 79, 0.95);
     color: #eeeeee
 }
 
@@ -32,3 +32,9 @@ button:hover {
     border: 1px dotted gray;
     border-radius: 15px
 }
+
+/* math operation result label */
+#math-label {
+    font-weight: bold;
+    font-size: 16px
+}