V18 Project Database (Why are there no built-in style sheets?)

I created a new v18 Project Database.

Then I select Style Sheets. (#1)

Three named styles sheets are listed.

Highlighting a style sheet name, I see a CREATE button. (#2)

Clicking the CREATE button automatically creates an empty CSS document in Project/Sources/. (#3)

QUESTION

Where is the default content for the CSS document that was automatically created?