margin-block-start

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.

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. 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 value	`0`
Applies to	same as `margin`
Inherited	no
Percentages	depends on layout model
Media	visual
Computed value	if specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, `auto`
Animatable	no
Canonical order	the unique non-ambiguous order defined by the formal grammar

Syntax

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

Values

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

Formal syntax

<'margin-left'>

Example

HTML Content

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

CSS Content

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 Level 1 The definition of 'margin-block-start' in that specification.	Editor's Draft	Initial definition

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	Not supported	41.0 (41.0)^[1]	Not supported	Not supported	Not supported

Feature	Android	Firefox Mobile (Gecko)	IE Phone	Opera Mobile	Safari Mobile
Basic support	Not supported	41.0 (41.0)^[1]	Not supported	Not supported	Not supported

[1] Available since Gecko 38, but behind the preference layout.css.vertical-text.enabled, then disabled by default.

margin-block-start

Syntax

Values

Formal syntax

Example

HTML Content

CSS Content

Specification

Browser compatibility

See also

Document Tags and Contributors