When you edit styles in a CSS file, all topics that are linked to the file are updated.
To edit a style, right-click on the CSS file in the Project Manager pod and click on Edit. Deselect the Hide Inherited Styles checkbox and select a style sheet from the Available In dropdown menu.
Select a style in the Styles box, click Format, and select the attributes and click OK.
Right-click on the CSS file in the Project Manager Pod and click Edit with Code Editor to open the style sheet in a new topic window. You can now edit the styles according to your requirement.