The border-block CSS property is a shorthand property for setting the individual logical block border property values in a single place in the style sheet.

border-block can be used to set the values for one or more of border-block-width, border-block-style, and border-block-color setting both the start and end in the block dimension at once. The physical borders to which it maps depends on the element's writing mode, directionality, and text orientation. It corresponds to the border-top and border-bottom or border-right, and border-left properties depending on the values defined for writing-mode, direction, and text-orientation.

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

Constituent properties

This property is a shorthand for the following CSS properties:


border-block: 1px;
border-block: 2px dotted;
border-block: medium dashed blue;

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


The border-block is specified with one or more of the following, in any order:

The width of the border. See border-width.
The line style of the border. See border-style.
The color of the border. See color.

Formal definition

Initial valueas each of the properties of the shorthand:
Applies toall elements
Computed valueas each of the properties of the shorthand:
Animation typediscrete

Formal syntax

<'border-top-width'> || <'border-top-style'> || <color>

<color> = <rgb()> | <rgba()> | <hsl()> | <hsla()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>

<rgb()> = rgb( <percentage>{3} [ / <alpha-value> ]? ) | rgb( <number>{3} [ / <alpha-value> ]? ) | rgb( <percentage>#{3} , <alpha-value>? ) | rgb( <number>#{3} , <alpha-value>? )
<rgba()> = rgba( <percentage>{3} [ / <alpha-value> ]? ) | rgba( <number>{3} [ / <alpha-value> ]? ) | rgba( <percentage>#{3} , <alpha-value>? ) | rgba( <number>#{3} , <alpha-value>? )
<hsl()> = hsl( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsl( <hue>, <percentage>, <percentage>, <alpha-value>? )
<hsla()> = hsla( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsla( <hue>, <percentage>, <percentage>, <alpha-value>? )

<alpha-value> = <number> | <percentage>
<hue> = <number> | <angle>


Border with vertical text


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


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

.exampleText {
  writing-mode: vertical-rl;
  border-block: 5px dashed blue;



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

Browser compatibility

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See also