:not() 否定是否接受后代选择器?
问题说明
我一直在使用 :not() 伪类来设置样式，而无需使用第二个不必要的声明来撤消第一个声明来覆盖它，但现在我遇到了一个奇怪的行为，Safari 接受 :not() 中的后代选择器，但 Chrome 不接受.
I've been using the :not() pseudo-class to style things without the need to override it with a second unnecessary declaration to undo the first one, but now I came across a weird behaviour where Safari accepts descendant selectors within the :not(), but Chrome doesn't.
我使用了类似 a:not(.blue a).
我搜索了答案，但我仍然不完全理解原因.
I searched for answers, but I still don't fully understand the reason.
Are descendant selectors really allowed by the spec?
这是一个演示:
a:not(.blue a) {
color: red;
}
<div><a>this one should be in red</a></div>
<div class="blue"><a>this one shouldn't</a></div>
正确答案
在 Selectors Level3，答案是否定的.:not() 表示法只接受 简单的选择器.
In Selectors Level 3, the answer would be NO. The :not() notation accepts only simple selectors.
否定伪类:not(X)是一个函数式记号简单选择器(不包括否定伪类本身)作为争论.它表示一个元素，它没有被它的论据.
The negation pseudo-class, :not(X), is a functional notation taking a simple selector (excluding the negation pseudo-class itself) as an argument. It represents an element that is not represented by its argument.
什么是简单选择器?
来自选择器语法:
简单选择器可以是类型选择器、通用选择器、属性选择器、类选择器、ID 选择器或伪类.
A simple selector is either a type selector, universal selector, attribute selector, class selector, ID selector, or pseudo-class.
与后代选择器无关.
但是，在 选择器级别4，:not() 接受复杂选择器，其中包括后代组合器.浏览器对该规范的支持仍然很弱.
HOWEVER, in Selectors Level 4, :not() accepts complex selectors, which would include descendant combinators. Browser support is still quite weak for this specification.
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