类选择器 - CSS（层叠样式表） 编辑

概述

在一个HTML文档中，CSS类选择器会根据元素的类属性中的内容匹配元素。类属性被定义为一个以空格分隔的列表项，在这组类名中，必须有一项与类选择器中的类名完全匹配，此条样式声明才会生效。

语法

.类名 {样式声明 }

注意它与下面的语句等价  attribute selector:

[class~=类名] {样式声明 }

示例

span.classy {
  background-color: DodgerBlue;
}

上面的CSS作用于下面的HTML代码:

  <span class="classy">Here's a span with some text.</span>
  <span>Here's another.</span>

则会产生这样的效果:

Here's a span with some text.

Here's another.

规范

Specification	Status	Comment
CSS Selectors Level 3	Recommendation
CSS 2.1	Recommendation
CSS 1	Recommendation

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

• Desktop
• Mobile

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari
Basic support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

Feature	Android	Chrome for Android	Firefox Mobile (Gecko)	IE Mobile	Opera Mobile	Safari Mobile
Basic support	?	?	?	?	?	?

See also