This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage 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 specification 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.
/* <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 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 |
| Animation type | discrete |
| Canonical order | the unique non-ambiguous order defined by the formal grammar |
Syntax
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 |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | No support | 41.0 (41.0)[1] | No support | No support | No support |
| Feature | Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|
| Basic support | No support | 41.0 (41.0)[1] | No support | No support | No support |
[1] Available since Gecko 38, but behind the preference layout.css.vertical-text.enabled, then disabled by default. The preference has been removed in Gecko 51 and this property cannot be disabled since this version.
See also
- The mapped physical properties:
margin-top,margin-right,margin-bottom, andmargin-left writing-mode,direction,text-orientation