3.1 CSS Levels
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Style sheets are typically described as "CSS 1", "CSS 2" and CSS3. CSS level 1 is typically supported by the 4.x browsers. CSS 2 is supported by IE 6 and later and by Netscape/Mozilla 6.2 and later. The recent versions of the Opera browser have excellent support for CSS 2; CSS3 is supported by most modern 8.0 and later computer browsers; some SmartPhone and Tablet browsers.
CSS 1 consists of the main font, border, color, and other tags to control the display.
CSS 2 allows you to add content to your page. For example, if you want to place the text "bullet" before each bullet you can do so.
CSS 2 also allows you to specify behaviors like what should happen when the cursor "hovers" over the element.
CSS3 - includes features like: new color formats, gradients and boarders (i.e.. rounded boarders, shadow borders), multiple columns, text shadow...


Net Links
CSS2 Specification

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