border-block-start-width
Defines the thickness of the logical 'start' border. It replaces 'border-top-width' in modern CSS to better support different writing directions.
It is documented as part of the CSS Logical Properties and Values specification.
Syntax
/* Usage Example */
header {
/* Logical top border */
border-block-start-width: 2px;
border-block-start-style: solid;
border-block-start-color: #333;
}
/* Syntax */
border-block-start-width: border-top-width;
/* Global values */
border-block-start-width: inherit;
border-block-start-width: initial;
border-block-start-width: revert;
border-block-start-width: revert-layer;
border-block-start-width: unset;border-block-start-width Browser support
Widely available
Since
2021 95% global usage
This feature is well established and works across many devices and browser versions. It has been available across browsers since 2021.
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