css property

`border-block-color` CSS property

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.

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.

Interactive exampleOpen the canonical MDN source to run this embedded demo.

border-block-color: red;
writing-mode: horizontal-tb;

border-block-color: #32a1ce;
writing-mode: vertical-rl;

border-block-color: rgb(170 50 220 / 0.6);
writing-mode: horizontal-tb;
direction: rtl;

<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element">
    This is a box with a border around it.
  </div>
</section>

#example-element {
  background-color: #eeeeee;
  color: black;
  border: 0.75em solid;
  padding: 0.75em;
  width: 80%;
  height: 100px;
  unicode-bidi: bidi-override;
}

Syntax

border-block-color: yellow;
border-block-color: #f5f6f7;

/* Global values */
border-block-color: inherit;
border-block-color: initial;
border-block-color: revert;
border-block-color: revert-layer;
border-block-color: unset;

Values

This property is specified as one <color> value:

<color>
- : The color of the border.

Formal definition

Formal syntax

Examples

Border 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: 10px solid blue;
  border-block-color: red;
}

Results

Interactive exampleOpen the canonical MDN source to run this embedded demo.

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.