在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 相关话题

CSS class selector matches elements based on the contents of their class 属性。

/* All elements with class="spacious" */
.spacious {
  margin: 2em;
}
/* All <li> elements with class="spacious" */
li.spacious {
  margin: 2em;
}
/* All <li> elements with a class list that includes both "spacious" and "elegant" */
/* For example, class="elegant retro spacious" */
li.spacious.elegant {
  margin: 2em;
}
					

句法

.class_name { style properties }
					

Note that this is equivalent to the following attribute selector :

[class~=class_name] { style properties }
					

范例

CSS

.red {
  color: #f33;
}
.yellow-bg {
  background: #ffa;
}
.fancy {
  font-weight: bold;
  text-shadow: 4px 4px 3px #77f;
}
					

HTML

<p class="red">This paragraph has red text.</p>
<p class="red yellow-bg">This paragraph has red text and a yellow background.</p>
<p class="red fancy">This paragraph has red text and "fancy" styling.</p>
<p>This is just a regular paragraph.</p>
					

结果

规范

规范	状态	注释
Selectors Level 4 The definition of 'class selectors' in that specification.	工作草案	No changes
Selectors Level 3 The definition of 'class selectors' in that specification.	推荐
CSS Level 2 (Revision 1) The definition of 'child selectors' in that specification.	推荐
CSS Level 1 The definition of 'child selectors' in that specification.	推荐	初始定义

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
Class selector ( .className )	Chrome 完整支持 1	Edge 完整支持 12	Firefox 完整支持 1	IE 完整支持 3	Opera 完整支持 3.5	Safari 完整支持 1	WebView Android 完整支持 ≤37	Chrome Android 完整支持 18	Firefox Android 完整支持 4	Opera Android 完整支持 10.1	Safari iOS 完整支持 1	Samsung Internet Android 完整支持 1.0

图例

完整支持

完整支持

元数据

• 最后修改： Jul 27, 2020

相关话题

1. CSS
2. CSS 参考
3. CSS Selectors
4. 指南

   1. Using the :target pseudo-class in selectors
5. 特性

   1. 选择器列表
6. Basic Selectors

   1. Type selectors
   2. Class selectors
   3. ID selectors
   4. Universal selectors
   5. Attribute selectors
7. 组合器

   1. Adjacent sibling combinator
   2. General sibling combinator
   3. Child combinator
   4. Descendant combinator
   5. Column combinator
8. Pseudo-classes

   1. :active
   2. :any-link
   3. :checked
   4. :blank
   5. :default
   6. :defined
   7. :dir()
   8. :disabled
   9. :empty
   10. :enabled
   11. :first
   12. :first-child
   13. :first-of-type
   14. :fullscreen
   15. :focus
   16. :focus-visible
   17. :focus-within
   18. :has()
   19. :host()
   20. :host-context()
   21. :hover
   22. :indeterminate
   23. :in-range
   24. :invalid
   25. :is() (:matches(), :any())
   26. :lang()
   27. :last-child
   28. :last-of-type
   29. :left
   30. :link
   31. :not()
   32. :nth-child()
   33. :nth-last-child()
   34. :nth-last-of-type()
   35. :nth-of-type()
   36. :only-child
   37. :only-of-type
   38. :optional
   39. :out-of-range
   40. :placeholder-shown
   41. :read-only
   42. :read-write
   43. :required
   44. :right
   45. :root
   46. :scope
   47. :target
   48. :valid
   49. :visited
   50. :where()
9. Pseudo-elements

   1. ::-moz-progress-bar
   2. ::-moz-range-progress
   3. ::-moz-range-thumb
   4. ::-moz-range-track
   5. ::-webkit-progress-bar
   6. ::-webkit-progress-value
   7. ::-webkit-slider-runnable-track
   8. ::-webkit-slider-thumb
   9. ::after (:after)
   10. ::backdrop
   11. ::before (:before)
   12. ::cue
   13. ::cue-region
   14. ::first-letter (:first-letter)
   15. ::first-line (:first-line)
   16. ::grammar-error
   17. ::marker
   18. ::part()
   19. ::placeholder
   20. ::selection
   21. ::slotted()
   22. ::spelling-error