Issue #3212792: In ui-dialog box button hover effect is odd

In ui-dialog box button hover effect is odd additionally the button background is removed in delete dialog box for content page. Closes #3212792

css/components/jquery.ui/theme.css

@@ -732,3 +732,16 @@
 .autocomplete .ui-state-hover a {
   color: #fff;
 }
+
+/* Dialog button */
+.ui-dialog-buttonset .ui-widget.button--primary {
+  background-color: #0071b8;
+  background-image: -webkit-linear-gradient(top, #007bc6, #0071b8);
+  background-image: linear-gradient(to bottom, #007bc6, #0071b8);
+}
+.ui-dialog-buttonset .ui-widget.button--primary:hover,
+.ui-dialog-buttonset .ui-widget.button--primary:focus {
+  background-color: #2369a6;
+  background-image: -webkit-linear-gradient(top, #0c97ed, #1f86c7);
+  background-image: linear-gradient(to bottom, #0c97ed, #1f86c7);
+}