border-block-start
==================

The **`border-block-start`** CSS property is a shorthand property for setting the individual logical block-start border property values in a single place in the style sheet.

Try it
------

Constituent properties
----------------------

This property is a shorthand for the following CSS properties:

* `border-block-start-color`
* `border-block-start-style`
* `border-block-start-width`
Syntax
------


```css
border-block-start: 1px;
border-block-start: 2px dotted;
border-block-start: medium dashed blue;

/\* Global values \*/
border-block-start: inherit;
border-block-start: initial;
border-block-start: revert;
border-block-start: revert-layer;
border-block-start: unset;
```


`border-block-start` can be used to set the values for one or more of `border-block-start-width`, `border-block-start-style`, and `border-block-start-color`. The physical border to which it maps depends on the element's writing mode, directionality, and text orientation. It corresponds to the `border-top`, `border-right`, `border-bottom`, or `border-left` property depending on the values defined for `writing-mode`, `direction`, and `text-orientation`.

Related properties are `border-block-end`, `border-inline-start`, and `border-inline-end`, which define the other borders of the element.

### Values

The `border-block-start` is specified with one or more of the following, in any order:

`<'border-width'>`

The width of the border. See `border-width`.

`<'border-style'>`

The line style of the border. See `border-style`.

`<color>`

The color of the border.

Formal definition
-----------------

|  |  |
| --- | --- |
| Initial value | as each of the properties of the shorthand:* `border-width`: as each of the properties of the shorthand:
    + `border-top-width`: `medium`
    + `border-right-width`: `medium`
    + `border-bottom-width`: `medium`
    + `border-left-width`: `medium`
* `border-style`: as each of the properties of the shorthand:
    + `border-top-style`: `none`
    + `border-right-style`: `none`
    + `border-bottom-style`: `none`
    + `border-left-style`: `none`
* `color`: `canvastext`
 |
| Applies to | all elements |
| Inherited | no |
| Computed value | as each of the properties of the shorthand:* `border-width`: as each of the properties of the shorthand:
    + `border-bottom-width`: the absolute length or `0` if `border-bottom-style` is `none` or `hidden`
    + `border-left-width`: the absolute length or `0` if `border-left-style` is `none` or `hidden`
    + `border-right-width`: the absolute length or `0` if `border-right-style` is `none` or `hidden`
    + `border-top-width`: the absolute length or `0` if `border-top-style` is `none` or `hidden`
* `border-style`: as each of the properties of the shorthand:
    + `border-bottom-style`: as specified
    + `border-left-style`: as specified
    + `border-right-style`: as specified
    + `border-top-style`: as specified
* `border-block-start-color`: computed color
 |
| Animation type | as each of the properties of the shorthand:* `border-block-start-color`: by computed value type
* `border-block-start-style`: discrete
* `border-block-start-width`: by computed value type
 |

Formal syntax
-------------
```

border-block-start =   
  <line-width>  ||  
  <line-style>  ||  
  <color>         
  
<line-width> =   
  <length [0,∞]>  |  
  thin            |  
  medium          |  
  thick             
  
<line-style> =   
  none    |  
  hidden  |  
  dotted  |  
  dashed  |  
  solid   |  
  double  |  
  groove  |  
  ridge   |  
  inset   |  
  outset    
  
```

Examples
--------

### Border with vertical text

#### HTML


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


#### CSS


```css
div {
  background-color: yellow;
  width: 120px;
  height: 120px;
}

.exampleText {
  writing-mode: vertical-rl;
  border-block-start: 5px dashed blue;
}
```

Specifications
--------------

| Specification |
| --- |
| CSS Logical Properties and Values Level 1 # border-shorthands |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* CSS Logical Properties and Values
* This property maps to one of the physical border properties: `border-top`, `border-right`, `border-bottom`, or `border-left`.
* `writing-mode`, `direction`, `text-orientation`