The Beta release of Firefox 3 is out and it comes with improved CSS support

• The display property’s inline-block and inline-table values are now implemented.
• The font-size-adjust property now works on all platforms; previously it was only supported on Windows.
• rgba() and hsla() support for color (bug 147017)
• :default pseudo-class support (bug 302186)
• -moz-max-content, -moz-min-content, -moz-fit-content, and -moz-available values have been added to width, min-width, and max-width (bug 311415 and bug 402706)
• HTML soft hyphens (­) are now supported.
• Pre-formatted tabs work much better in proportional fonts, following the CSS 2.1 spec.
• The ime-mode property is supported.
• The CSS text-rendering property for HTML is now supported (bug 387969).
• -moz-border-*-start and -moz-border-*-end CSS properties are implemented (bug 74880).
• -moz-initial is now implemented for almost all CSS properties (except quotes and -moz-border-*-colors) bug 80887.
• window.getComputedStyle() now supports all supported CSS properties (bug 316981).
• content’s none value is now supported (bug 378535).
• cursor’s none value is now supported (bug 346690).
• Background images now properly clip to a -moz-border-radius (bug 24998).
• white-space’s pre-wrap value is now supported (bug 261081).
• Selectors like :first-child, :only-child, :last-child (bug 73586), :empty (bug 98997), or the + combinator (bug 229915) are now updated dynamically (bug 401291).
• Negative z-index values are supported correctly.