Survey form - having trouble with background

I was trying to design a survey form without copying too much from the example article, but one thing I did want to try and use was their background setup. I can’t figure out how to color just the outside edges of the document like they had in their example. Any help would be appreciated!

Their Survey Form:

My Survey form:

You are missing the opening form tag. You should also use actual <label> elements for your labels and not <div> elements.

Anyway, elements are transparent by default. If you give the form element, or a parent container to the form like in the example project, a background color you will get the result you are looking for.