The border-block-width CSS property is shorthand for border-block-start-width and border-block-end-width.
CSS
border-block-width: value;
JS
object.style.borderBlockWidth = "value";
Values
<'border-block-width'> = <'border-top-width'>{1,2}
<'border-top-width'> = <line-width>
<line-width> = <length [0,∞]> | thin | medium | thick
<length>
Specifies the length using a number followed by a unit of measurement.
Initial
length
medium
thick
thin
JS
Internal
External