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border-block-width

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 value medium
Applies to all elements
Inherited no
Percentages logical-width of containing block
Computed value absolute length; 0 if the border style is none or hidden
Animation type discrete

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

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
border-block-width 69 79 66 No 56 No
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
border-block-width 69 69 66 48 No 10.0

See also

© 2005–2020 Mozilla and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/border-block-width