Update style.css

style.css

@@ -60,12 +60,16 @@ button:hover {
 }
 
 .grid-wrapper {
-    border: none;
     padding: 10px;
     display: flex;
     justify-content: center;
+    background-color: #f0f0f0;
+    border: 2px solid #d0d0d0;
+    border-radius: 12px;
+    box-shadow: inset 0 0 6px rgba(0,0,0,0.05);
 }
 
+
 .grid {
     display: grid;
     grid-template-columns: repeat(15, minmax(30px, 1fr));