Adds a content style sheet from a string.
- Safari Desktop 5.0+
- Safari Extensions JS
The source code of the style sheet.
A list of patterns matching URLs of pages to which the script should be applied.
A list of patterns matching URLs of pages to which the script should not be applied.
If the style sheet was successfully added, a generated URL that can be used to remove it; otherwise,
The style sheet behaves like a user-level style sheet. It is loaded after user-level style sheets and it can override them, as well as overriding page-level style sheets.
Pages that are already loaded are updated to use the style sheet after it is added.