A method is provided comprising: retrieving a markup language file associated with a document, the markup language file including an identifier for retrieving a content item that is part of the document; parsing the markup language file into a first plurality of objects, the first plurality of objects including a first object associated with the content item; assigning a respective layout level to each one of the first plurality of objects; and outputting the document in accordance with a first layout level by: (i) retrieving the content item from a remote source in response to the layout level of the first object matching the first layout level, and (ii) rendering one or more objects from the first plurality based the one or more objects' respective layout levels matching the first layout level.