CSS - border-block-start-style


HTML Content

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

CSS Content

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

.exampleText {
  writing-mode: vertical-lr;
  border: 5px solid blue;
  border-block-start-style: dashed;


border-block-start-style: dashed;
border-block-start-style: dotted;
border-block-start-style: groove;


See border-style

Formal syntax



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-styleborder-right-styleborder-bottom-style, or border-left-style property depending on the values defined for writing-mode, direction, and text-orientation.

It relates to border-block-end-styleborder-inline-start-style, and border-inline-end-style, which define the other border styles of the element.

Initial valuenone
Applies toall elements
Computed valueas specified
Canonical orderthe unique non-ambiguous order defined by the formal grammar

Browser Compatibility  

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support Not supported 41.0 (41.0)[1] Not supported Not supported Not supported
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support Not supported 41.0 (41.0)[1] Not supported Not supported Not supported

[1] Available since Gecko 38, but behind the preference layout.css.vertical-text.enabled, then disabled by default.

See Also  


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


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