border-block-width

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The border-block-width CSS property defines the width of the logical block borders of an element, which maps to a physical border width depending on the element's writing mode, directionality, and text orientation. It corresponds to the border-top-width and border-bottom-width, or border-left-width, and border-right-width property depending on the values defined for writing-mode, direction, and text-orientation.

/* <'border-width'> values */
border-block-width: 5px;
border-block-width: thick;

The border width in the other dimension can be set with border-inline-width, which sets border-inline-start-width, and border-inline-end-width.

Syntax

Values

<'border-width'>
The width of the border. See border-width.

Formal definition

Initial valuemedium
Applies toall elements
Inheritedno
Percentageslogical-width of containing block
Computed valueabsolute length; 0 if the border style is none or hidden
Animation typediscrete

Formal syntax

<'border-top-width'>

Examples

Border width with vertical text

HTML

<div>
  <p class="exampleText">Example text</p>
</div>

CSS

div {
  background-color: yellow;
  width: 120px;
  height: 120px;
}

.exampleText {
  writing-mode: vertical-lr;
  border: 1px solid blue;
  border-block-width: 5px;
}

Results

Specifications

Specification Status Comment
CSS Logical Properties and Values Level 1
The definition of 'border-block-width' in that specification.
Editor's Draft Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
border-block-widthChrome Full support 69Edge Full support 79Firefox Full support 66IE No support NoOpera Full support 56Safari No support NoWebView Android Full support 69Chrome Android Full support 69Firefox Android Full support 66Opera Android Full support 48Safari iOS No support NoSamsung Internet Android Full support 10.0

Legend

Full support  
Full support
No support  
No support

See also