True if cascading style sheets (CSS) are used for font formatting when you view a saved document in a Web browser. Microsoft Excel creates a cascading style sheet file and saves it either to the specified folder or to the same folder as your Web page, depending on the value of the OrganizeInFolder property. False if HTML <FONT> tags and cascading style sheets are used. The default value is True. Read/write Boolean.
Remarks
You should set this property to True if your Web browser supports cascading style sheets, as this will give you more precise layout and formatting control on your Web page and make it look more like your document (as it appears in Microsoft Excel).
Example
This example enables the use of cascading style sheets as the global default for the application.
Application.DefaultWebOptions.RelyOnCSS = True