First, from the schema (which is the definitive source, and which you need to validate your style):

cs-types =
"article"
| "article-magazine"
| "article-newspaper"
| "article-journal"
| "bill"
| "book"
| "chapter"
| "entry"
| "entry-dictionary"
| "entry-encyclopedia"
| "figure"
| "graphic"
| "interview"
| "legislation"
| "legal_case"
| "manuscript"
| "map"
| "motion_picture"
| "musical_score"
| "pamphlet"
| "paper-conference"
| "patent"
| "post"
| "post-weblog"
| "personal_communication"
| "report"
| "review"
| "review-book"
| "song"
| "speech"
| "thesis"
| "treaty"
| "webpage"


Second, I strongly urge you to first see if you can get what you want without using "type." First, you'll note there is no 'website' type. Second, this list may be subject to some change. Third, you can almost always achieve more reliable and general formatting by conditioning formatting on other criteria, such as the presence of particular variables.