margin-block

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2021.

The margin-block CSS shorthand property defines the logical block start and end margins of an element, which maps to physical margins depending on the element's writing mode, directionality, and text orientation.

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Constituent properties

This property is a shorthand for the following CSS properties:

Syntax

css
/* <length> values */
margin-block: 10px 20px; /* An absolute length */
margin-block: 1em 2em; /* relative to the text size */
margin-block: 5% 2%; /* relative to the nearest block container's width */
margin-block: 10px; /* sets both start and end values */
margin-block: anchor-size(inline);
margin-block: calc(anchor-size(width) / 4) 1em;

/* Keyword values */
margin-block: auto;

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

This property corresponds to the margin-top and margin-bottom, or the margin-right and margin-left properties, depending on the values defined for writing-mode, direction, and text-orientation.

The margin-block property may be specified using one or two values.

  • When one value is specified, it applies the same margin to both start and end.
  • When two values are specified, the first margin applies to the start, the second to the end.

Values

The margin-block property takes the same values as the margin property.

Formal definition

Initial valueas each of the properties of the shorthand:
Applies tosame as margin
Inheritedno
Percentagesdepends on layout model
Computed valueas each of the properties of the shorthand:
  • margin-block-start: if specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, auto
  • margin-block-end: if specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, auto
Animation typea length

Formal syntax

margin-block = 
  <'margin-top'>{1,2}  

<margin-top> = 
  <length-percentage>  |
  auto                 |
  <anchor-size()>      

<length-percentage> = 
  <length>      |
  <percentage>  

<anchor-size()> = 
  anchor-size( [ <anchor-name> || <anchor-size> ]? , <length-percentage>? )  

<anchor-name> = 
  <dashed-ident>  

<anchor-size> = 
  width        |
  height       |
  block        |
  inline       |
  self-block   |
  self-inline

Examples

Setting block start and end margins

CSS

css
div {
  background-color: yellow;
  width: 120px;
  height: auto;
  border: 1px solid green;
}

p {
  margin: 0;
  margin-block: 20px 40px;
  background-color: tan;
}

.verticalExample {
  writing-mode: vertical-rl;
}

HTML

html
<div>
  <p>Example text</p>
</div>
<div class="verticalExample">
  <p>Example text</p>
</div>

Result

Specifications

Specification
CSS Logical Properties and Values Level 1
# propdef-margin-block

Browser compatibility

BCD tables only load in the browser

See also