You can upload a CSS file to control styling of proxied content, so that your content follows EdWeb styles, for example styling a proxied from.
Example styled form
You can also upload a JS file to control proxied content, to take advantage of existing EdWeb JS classes, such as jQuery. For example, you can show or hide elements depending on user selections:
This is the initial content.Show some additional content
This is some additional content.Show the initial content
There is comprehensive guidance about the web application content type on the EdWeb support wiki.