margin-block-start

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

Syntax

/* <length> values */
margin-block-start: 10px;  /* An absolute length */
margin-block-start: 1em;   /* relative to the text size */
margin-block-start: 5%;    /* relative to the nearest block container's width */

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

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

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

It relates to margin-block-end, margin-inline-start, and margin-inline-end, which define the other margins of the element.

Values

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

Formal definition

Initial value0
Applies tosame as margin
Inheritedno
Percentagesdepends on layout model
Computed valueif specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, auto
Animation typea length

Formal syntax

<'margin-left'>

Examples

Setting block start margin

HTML

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

CSS

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

.exampleText {
  writing-mode: vertical-lr;
  margin-block-start: 20px;
  background-color: #c8c800;
}

Result

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
margin-block-startChrome Full support 69Edge Full support 79Firefox Full support 41
Full support 41
No support 38Ā ā€” 51
Disabled
Disabled From version 38 until version 51 (exclusive): this feature is behind the layout.css.vertical-text.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 56Safari Full support 12.1WebView Android Full support 69Chrome Android Full support 69Firefox Android Full support 41
Full support 41
No support 38Ā ā€” 51
Disabled
Disabled From version 38 until version 51 (exclusive): this feature is behind the layout.css.vertical-text.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 48Safari iOS Full support 12.2Samsung Internet Android Full support 10.0

Legend

Full support Ā 
Full support
No support Ā 
No support
User must explicitly enable this feature.
User must explicitly enable this feature.

See also