rgba() and hsla() should not exist, rgb() and hsl() should have gotten an optional fourth parameter instead (and the alpha value should have used the same format as R, G, and B or S and L).
rgba() 和 hsla() 不应该存在， rgb() 和 hsl() 应该有第四个可选的参数（并且 alpha 的值的格式应该和 R，G 和 B 或 S 和 L 的一致）。
descendant combinator should have been »
and indirect sibling combinator should have been ++, so there's some logical relationships among the selectors' ascii art
后代选择器应该是 » 不相邻的兄弟选择器应该是 ++，这样通过选择器可以知道元素间逻辑上的关系。
the *-blend-mode properties should've just been *-blend
*-blend-mode属性应该叫 *-blend 就可以了。
The syntax of unicode ranges should have consistent with the rest of CSS, likeu0001-u00c8.
unicode 的范围语法应该和 CSS 的其他语法一致，如 u0001-u00c8。
font-family should have required the font name to be quoted (like all other values that come from “outside” CSS). The rules for handling unquoted font names make parsing font stupid, as it requires a font-size value for disambiguation.
Flexbox should have been less crazy about flex-basis vs width/height. Perhaps: if width/height is auto, use flex-basis; otherwise, stick with width/height as an inflexible size. (This also makes min/max width/height behavior fall out of the generic definition.)
:empty should have been :void, and :empty should select items that contain only white space
:empty 应该叫 :void，并且 :empty 包括只内容只有空格的元素。
table-layout: fixed; width: auto should result in a fill-available table with fixed-layout columns.
'text-orientation' should have had upright as the initial value (given the latest changes to 'writing-mode').
'text-orientation' 的初始值应该是 upright（不知道怎么译）。
The @import rule is required to (a) always hit the network unless you specify cache headers, and (b) construct fresh CSSStyleSheet objects for every import, even if they're identical. It should have had more aggressive URL-based deduping and allowed sharing of stylesheet objects.
Selectors have terrible future-proofing. We should have split on top-level commas, and only ignored unknown/invalid segments, not the entire thing.
:link should have had the :any-link semantics all along.