Style loading panel

services/web/public/stylesheets/app/editor.less

@@ -169,6 +169,18 @@
 	right: 0;
 }
 
+.loading {
+	position: absolute;
+	top: 0;
+	bottom: 0;
+	left: 0;
+	right: 0;
+	padding-top: 10rem;
+	font-family: @font-family-serif;
+	text-align: center;
+	background-color: #fafafa;
+}
+
 // The internal components of the aceEditor directive
 .ace-editor-wrapper {
 	position: absolute;