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.

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

Values

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

Formal syntax

<'margin-left'>

Example

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;
}

Specification

Specification Status Comment
CSS Logical Properties and Values Level 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 38 — 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 38 — 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  
Full support
No support  
No support
User must explicitly enable this feature.
User must explicitly enable this feature.

See also