border-block-start-style

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

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.

Try it

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;


  
    This is a box with a border around it.

#example-element {
  background-color: #eee;
  color: #000;
  border: 0.75em solid;
  padding: 0.75em;
  width: 80%;
  height: 100px;
  unicode-bidi: bidi-override;
}

Syntax

css

/* <'border-style'> 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

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

Formal definition

Initial value	`none`
Applies to	all elements
Inherited	no
Computed value	as specified
Animation type	discrete

Formal syntax

border-block-start-style = 
    

 = 
  none    |
  hidden  |
  dotted  |
  dashed  |
  solid   |
  double  |
  groove  |
  ridge   |
  inset   |
  outset

Examples

Dashed border with vertical text

HTML

html


  Example text

CSS

css

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

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

Results

Specifications

Specification
CSS Logical Properties and Values Level 1 # border-style