You can add custom CSS style rules here which are not yet directly supported by this editor. Each rule must be on a separate line. There is no need to add semi-colon at the end of each rule. It will be added automatically. For example:
line-height : 40px
text-decoration : underline
Please note that no validation will be performed on them. Inappropriate style rules will cause your web pages to be rendered incorrectly. These styles can only be previewed in internal or exteranl browsers but not in Page Designer.