避免使用 CSS-wide keywords

[yisibl]

CSS 规范中定义了一些保留关键字，我们应该在 <custom-ident> 中避免使用这些值。历史遗留原因，虽然当前某些浏览器支持这些值，但在将来可能会禁用，这会导致相关 CSS 失效。

TODO: CSS 示例

详见：

• [css-values] unify CSS wide keywords and defaulting keywords w3c/csswg-drafts#7170
• [css-values] add 'revert' and 'revert-layer' to list of CSS-wide keywords w3c/csswg-drafts#7439

这些关键字当前散落在不同的规范，包括：

css-values-4

https://www.w3.org/TR/css-values-4/#common-keywords

Defined:

• initial
• inherit
• unset

css-cascade-4

https://drafts.csswg.org/css-cascade/#defaulting-keywords

Defined:

• initial
• inherit
• unset
• revert

css-cascade-5

https://drafts.csswg.org/css-cascade-5/#revert-layer

Defined:

• initial
• inherit
• unset
• revert
• revert-layer

css-values-4

https://www.w3.org/TR/css-values-4/#ref-for-css-wide-keywords

The CSS-wide keywords are not valid <custom-ident>s. The default keyword is reserved and is also not a valid <custom-ident>

There is a default keyword.