Added custom scrollbar.

app/client/app.css

@@ -1212,3 +1212,18 @@ nav form input[type="image"]{
     background-color: transparent;
     color:#ffffff;
 }
+
+/* https://css-tricks.com/custom-scrollbars-in-webkit/ */
+
+::-webkit-scrollbar {
+    width: 8px;
+}
+
+::-webkit-scrollbar-track {
+    border-radius: 10px;
+}
+
+::-webkit-scrollbar-thumb {
+    border-radius: 10px;
+    background-color: white;
+}