没有媒体类型的@media 规则是做什么的？

Question

我继承了这个，想知道没有 "media type" 的媒体查询有什么作用？

 @media (min-width: 768px) {
   .commentlist-item .commentlist-item {
    padding: 0 0 0 2em;
   }
}

www.w3schools 的标准语法。com/css/css3_mediaqueries.asp

  @media not|only mediatype and (expressions) {
    CSS-Code;
}

Answer 1

If the media type is not explicitly given it is all. ~ W3C Media Queries

换句话说，没有媒体类型的@media 规则是shorthand 语法，其中隐含all。

更多来自规范：

2. Media Queries

A shorthand syntax is offered for media queries that apply to all media types; the keyword all can be left out (along with the trailing and). I.e. if the media type is not explicitly given it is all.

EXAMPLE 5

I.e. these are identical:
@media all and (min-width: 500px) { ... } 
@media (min-width: 500px) { ... }
As are these:
@media (orientation: portrait) { ... }
@media all and (orientation: portrait) { ... }
...

EXAMPLE 7

I.e. these are equivalent:
@media all { ... }
@media { ... }
_{source: https://www.w3.org/TR/css3-mediaqueries/#media0}

没有媒体类型的@media 规则是做什么的？

What's a @media rule without a media type do?

css

media-queries