"Let us prepare our minds as if we'd come to the very end of life. Let us postpone nothing. Let us balance life's books each day ... The one who puts the finishing touches on their life each day is never short of time."
Seneca

border-block-width

The border-block-width CSS property defines the width of the logical block borders of an element, which maps to a physical border width depending on the element's writing mode, directionality, and text orientation. It corresponds to the border-top-width and border-bottom-width, or border-left-width, and border-right-width property depending on the values defined for writing-mode, direction, and text-orientation.
border-block-width css reference