You can take advantage of cascading stylesheets (CSS files) and the rules around them to control the look of your output in one place. This helps to keep the content separate from its presentation, which is very important when it comes to single-sourcing. CSS isn’t a MadCap Software idea. It’s an international standard for formatting web content, and it was developed by a group called the World Wide Web Consortium (or W3C). You can learn all about the W3C at w3.org.
You might use styles from those provided by Contributor, from new stylesheets that you create, or from templates or topics sent to you by Flare authors.