Yes, only a few CSS attributes are allowed. You directly use the attribute from a list of options for the property in the Expression.
Alignment, Padding, font related items etc are all set using their attributes.
The Text "Total" has been replaced by the one shown in the figure using the following for the CSS attributes:
Font: Verdana to Jokerman
Font-size: 9pt to 16pt
Alignment: Default to Center
Fill: #920202 to Dark Violet