Here you can define any CSS classes required to style the appearance and design of the web part. The specified styles will be loaded by pages where the given web part is placed. Please note that this requires the Allow CSS from components setting to be enabled in Site Manager -> Settings -> System -> Performance.

 

Additional information can be found in:

 

•Developer's Guide -> Development -> Web parts -> Overview

•Developer's Guide -> Development -> CSS stylesheets and design -> CSS for page components