:first-child

:first-child CSS pseudo-class đại diện cho phần tử đầu tiên trong số các phần tử anh chị em của nó.

/* Chọn thẻ <p> đầu tiên trong số các thẻ anh chị em của nó*/
p:first-child {
  color: lime;
}

Note: As originally defined, the selected element had to have a parent. Beginning with Selectors Level 4, this is no longer required.

Cú pháp

:first-child

Ví dụ

Ví dụ đơn giản

HTML

<div>
  <p>This text is selected!</p>
  <p>This text isn't selected.</p>
</div>

<div>
  <h2>This text isn't selected: it's not a `p`.</h2>
  <p>This text isn't selected.</p>
</div>

CSS

p:first-child {
  color: lime;
  background-color: black;
  padding: 5px;
}

Kết quả

Styling một danh sách

HTML

<ul>
  <li>Item 1</li>
  <li>Item 2</li>
  <li>Item 3
    <ul>
      <li>Item 3.1</li>
      <li>Item 3.2</li>
      <li>Item 3.3</li>
    </ul>
  </li>
</ul>

CSS

ul li {
  color: blue;
}

ul li:first-child {
  color: red;
  font-weight: bold;
}

Result

Specifications

Specification Status Comment
Selectors Level 4
The definition of ':first-child' in that specification.
Working Draft Matching elements are not required to have a parent.
Selectors Level 3
The definition of ':first-child' in that specification.
Recommendation No change.
CSS Level 2 (Revision 1)
The definition of ':first-child' in that specification.
Recommendation Initial definition.

Khả năng tương thích của trình duyệt

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
:first-childChrome Full support 4Edge Full support 12Firefox Full support 3IE Full support 7
Notes
Full support 7
Notes
Notes Internet Explorer 7 doesn't update :first-child styles when elements are added dynamically.
Notes In Internet Explorer 8, if an element is inserted dynamically by clicking on a link, then the :first-child style isn't applied until the link loses focus.
Opera Full support 9.5Safari Full support 3.1WebView Android Full support ≤37Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 4Samsung Internet Android Full support 1.0
Matches elements with no parentChrome Full support 57Edge No support NoFirefox Full support 52IE No support NoOpera Full support 44Safari No support NoWebView Android Full support 57Chrome Android Full support 57Firefox Android Full support 52Opera Android Full support 43Safari iOS No support NoSamsung Internet Android Full support 7.0

Legend

Full support  
Full support
No support  
No support
See implementation notes.
See implementation notes.

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