Cascading Style Sheets Level 3

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What Does Cascading Style Sheets Level 3 Mean?

Cascading Style Sheets Level 3 (CSS3) is the iteration of the CSS standard used in the styling and formatting of Web pages. CSS3 incorporates the CSS2 standard with some changes and improvements.


A key change is the division of standard into separate modules, which makes it easier to learn and understand. As of February 2014, the standard is still under development by the World Wide Web Consortium (W3C), but a number of the CSS3 properties have been implemented in the latest versions of some Web browsers.

Techopedia Explains Cascading Style Sheets Level 3

CSS3 makes changes to how some visual elements are implemented and rendered by a browser. However, it is not a single hugely unwieldy specification, unlike CSS2. CSS3 is separated into separate modules to facilitate development. This means that the specification comes out in chunks, with more stable modules than others.

Some would be ready for recommendation, while others would be marked as under development drafts, the most recent of which were published as early as June 1999.

Some of the major modules of CSS3 are:

  • Box model

  • Image values and replaced content

  • Text effects

  • Selectors

  • Backgrounds and borders

  • Animations

  • User interface (UI)

  • Multiple column layout

  • 2D/3D transformations


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Margaret Rouse
Senior Editor
Margaret Rouse
Senior Editor

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.