Appendix B: Changes from CSS1
CSS2 builds on [CSS1] and all valid CSS1 style sheets are valid
CSS2 style sheets. The changes between the CSS1 specification and this
specification fall into three groups: new functionality, updated
descriptions of CSS1 functionality, and changes to CSS1.
2.1 New functionality
In addition to the functionality of CSS1, CSS2 supports:
- The concept of media types.
- Paged media
- Aural style sheets
- An extended font selection
mechanism, including intelligent matching, synthesis, and downloadable
fonts. Also, the concept of system fonts has been is introduced, and a
new property, 'font-size-adjust', has been added.
- Tables, including new values on 'display' and 'vertical-align'.
- Relative and Absolute positioning,
including fixed positioning.
- An extended selector mechanism,
including child selectors, adjacent selectors and attribute selectors.
- Generated content and automatic
- Text shadows, through the new
- 'text-shadow' property.
- A new anchor
- System colors
2.2 Updated descriptions
The CSS1 specification was short and concise. This specification is
much more voluminous and more readable. Much of the additional content
describes new functionality, but the description of CSS1 features has
also been extended. Except in a few cases described below, the
rewritten descriptions do not indicate a change in syntax nor
- In CSS2 color values are clipped
with regard to the device gamut, not with regard to the sRGB gamut as
- [strength of constraints based on writing direction]
- In CSS1, several properties (e.g. 'padding') had values referring
to the width of the parent element. This was an error; the value
should always refer to the width of a block-level element and this
specification reflects this.
- Initial value of 'display' is 'inline', not 'block' as in CSS1.
- [the 'clear' property now only applies to block-level elements]