XWIKI-10986: "Loading" is not hovering the all page.

xwiki-platform-core/xwiki-platform-flamingo/xwiki-platform-flamingo-theme/src/main/resources/FlamingoThemesCode/ThemeSheet.xml

@@ -385,12 +385,10 @@
     // Put a gray curtain in front of the iframe
     var addCurtain = function() {
       var iframePosition = iframe.position();
-      var iframeWidth = iframe.width();
-      var iframeHeight = iframe.height();
       $("<div id=\"preview-curtain\"><h2>$services.localization.render('platform.flamingo.themes.loading')</h2></div>").insertAfter(iframe);
       var previewCurtain = $("#preview-curtain");
-      previewCurtain.width(iframe.width());
-      previewCurtain.height(iframe.height());
+      previewCurtain.width(iframe.outerWidth(true));
+      previewCurtain.height(iframe.outerHeight(true));
       previewCurtain.css("left", iframePosition.left);
       previewCurtain.css("right", iframePosition.right);
     }