W3C and CSS Resources
The vast majority of the styles and properties in Flare were developed by the World Wide Web Consortium (W3C). For more thorough information about each W3C style and property, refer to https://www.w3.org and use the search feature on the website.
In addition to the W3C, several recorded webinars dealing with CSS are available on the MadCap Software website:
http://www.madcapsoftware.com/resources/recordedwebinars.aspx#flare
Also, this is a good online resource for learning about CSS:
http://www.w3schools.com/css/css_intro.asp
In addition to the many standard styles from W3C, you might notice several unique-looking styles that begin with the word "MadCap" (e.g., MadCap|footnote, MadCap|toggler). There are also many MadCap-specific properties. You will recognize these properties because they always start with "mc" (e.g., mc-footnote-format, mc-hyphenate).