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

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

border-block-color: yellow;
border-block-color: #F5F6F7;

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

Value not found in DB!



The color of the border. See color.

Formal syntax

Syntax not found in DB!


HTML Content

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

CSS Content

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

.exampleText {
  writing-mode: vertical-lr;
  border: 10px solid blue;
  border-block-color: red;


Browser compatibilityUpdate compatibility data on GitHub

Chrome Edge Firefox Internet Explorer Opera Safari
Basic support No No No No No No
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support No No No No No No No

See also

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