css property

`border-block-start-style` CSS property

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

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

border-block-start-style: dotted;
writing-mode: horizontal-tb;

border-block-start-style: dotted;
writing-mode: vertical-rl;

border-block-start-style: groove;
writing-mode: horizontal-tb;

border-block-start-style: dashed;
writing-mode: vertical-lr;

<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

/* Keyword values */
border-block-start-style: dashed;
border-block-start-style: dotted;
border-block-start-style: groove;

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

Related properties are border-block-end-style, border-inline-start-style, and border-inline-end-style, which define the other border styles of the element.

Values

<line-style>
- : The line style of the border. See border-style.

Formal definition

Formal syntax

Examples

Dashed 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: 5px solid blue;
  border-block-start-style: dashed;
}

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.