The inset-block-start CSS property defines the logical block start offset of an element, which maps to a physical inset depending on the element's writing mode, directionality, and text orientation. It corresponds to the top, right, bottom, or left property depending on the values defined for writing-mode, direction, and text-orientation.
/* <length> values */ inset-block-start: 3px; inset-block-start: 2.4em; /* <percentage>s of the width or height of the containing block */ inset-block-start: 10%; /* Keyword value */ inset-block-start: auto; /* Global values */ inset-block-start: inherit; inset-block-start: initial; inset-block-start: unset;
Syntax
Values
The inset-block-start property takes the same values as the left property.
Formal definition
| Initial value | auto |
|---|---|
| Applies to | positioned elements |
| Inherited | no |
| Percentages | logical-height of containing block |
| Computed value | same as box offsets: top, right, bottom, left properties except that directions are logical |
| Animation type | a length, percentage or calc(); |
Formal syntax
<'top'>
Examples
Setting block start offset
HTML
<div> <p class="exampleText">Example text</p> </div>
CSS
div {
background-color: yellow;
width: 120px;
height: 120px;
}
.exampleText {
writing-mode: vertical-lr;
position: relative;
inset-block-start: 20px;
background-color: #c8c800;
}
Specifications
| Specification | Status | Comment |
|---|---|---|
| CSS Logical Properties and Values Level 1 The definition of 'inset-block-start' in that specification. |
Editor's Draft | Initial definition |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
inset-block-start | Chrome
Full support
69
| Edge
Full support
79
| Firefox
Full support
63
| IE No support No | Opera
Full support
56
| Safari No support No | WebView Android No support No | Chrome Android
Full support
69
| Firefox Android
Full support
63
| Opera Android
Full support
48
| Safari iOS No support No | Samsung Internet Android No support No |
Legend
- Full support
- Full support
- No support
- No support
- User must explicitly enable this feature.
- User must explicitly enable this feature.
- Uses a non-standard name.
- Uses a non-standard name.
See also
- The properties which defines other insets:
inset-block-end,inset-inline-start, andinset-inline-end - The mapped physical properties:
top,right,bottom, andleft writing-mode,direction,text-orientation
