border-block-start
A shorthand for setting the width, style, and color of the 'start' side border in the block dimension. Effectively styles the top border in horizontal writing modes.
It is documented as part of the CSS Logical Properties and Values specification.
Syntax
/* Usage Example */
main {
/* Logical equivalent of border-top */
border-block-start: 2px solid #000;
}
/* Syntax */
border-block-start: border-top-width;
border-block-start: border-top-style;
/* 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 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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