This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The offset-block-start CSS property defines the logical block start offset of an element, which maps to a physical offset 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 */ offset-block-start: 3px; offset-block-start: 2.4em; /* <percentage>s of the width or height of the containing block */ offset-block-start: 10%; /* Keyword value */ offset-block-start: auto; /* Global values */ offset-block-start: inherit; offset-block-start: initial; offset-block-start: unset;
It relates to offset-block-end, offset-inline-start, and offset-inline-end, which define the other offsets of the element.
| Initial value | auto |
|---|---|
| Applies to | positioned elements |
| Inherited | no |
| Percentages | logical-height of containing block |
| Media | visual |
| Computed value | same as box offsets: top, right, bottom, left properties except that directions are logical |
| Animation type | discrete |
| Canonical order | the unique non-ambiguous order defined by the formal grammar |
The offset-block-start property takes the same values as the left property.
<'left'>
<div> <p class="exampleText">Example text</p> </div>
div {
background-color: yellow;
width: 120px;
height: 120px;
}
.exampleText {
writing-mode: vertical-lr;
position: relative;
offset-block-start: 20px;
background-color: #c8c800;
} | Specification | Status | Comment |
|---|---|---|
| CSS Logical Properties and Values Level 1 The definition of 'offset-block-start' in that specification. | Editor's Draft | Initial definition |
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | No | ? |
41 38 — 511 |
No | No | No |
| Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
|---|---|---|---|---|---|---|---|
| Basic support | No | ? | ? |
41 38 — 511 |
No | No | ? |
1. 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.
top, right, bottom, and left
writing-mode, direction, text-orientation
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/offset-block-start