Cascading Style Sheets, level 2
CSS2 Specification
W3C Recommendation 12-May-1998

2.4 CSS design principles
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Richness. Providing authors with a rich set of rendering effects increases the richness of the Web as a medium of expression. Designers have been longing for functionality commonly found in desktop publishing and slide-show applications. Some of the requested rendering effects conflict with device independence, but CSS2 goes a long way toward granting designers their requests.
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http://www.w3.org/TR/REC-CSS2/intro.html#q6