About attaching cascading style sheets
You can use Microsoft Word to attach, remove, and manage cascading style sheets (CSS) for Web pages. Cascading style sheets provide a convenient way to format several Web pages or a whole Web site. To change the format of the pages, you can make changes to the style sheet without having to edit each Web page.
You can use Word to attach more than one style sheet. For example, you might have a style sheet that's part of a large Web site, such as one for a university, and then another style sheet that defines a smaller group of related pages, such as one for a department within the university.
You can also determine which style sheet takes precedence over another, in case conflicting styles are defined for the same elements.
When you attach a style sheet to your Web page in Word, the styles will appear in the Styles and Formatting task pane.