Vim's built-in syntax/css.vim has some bugs and some of these bugs cannot be fixed with after/syntax/css.vim. This patched syntax file fixes all bugs I know:

• braile, embosed, and ty are typo
• clip() function is deprecated
• page, size, marks, and inside are not valid properties
• landscape, portrait, crop, and cross are not valid values
• text and progress values are missing
• text-row-gorup is typo
• pre-wrap and pre-line values are missing
• speak-numerals is typo
• speak-header is cssAuralProp, not cssTableProp
• pitch property is missing
• low, high, x-low, and x-high values are missing
• object element is missing
• sans-serif cannot be highlighted when set iskeyword+=-
• background-repeat property is missing
• contained argument is missing in one of the cssTextProp
• text-indent property is not cssTextAttr, is cssTextProp
• inline-block value is missing
• run-in, inline-table, and list-item are not cssRenderProp, are cssRenderAttr

Patches welcome!