The pseudo-element, the size of this block with a border, have absolute positioning exactly over it. Then the pseudo-element makes a border on the right and the top do not. That's all. A similar example:
Do not forget about pointer-events: none, not to obstruct access to the content.
Aliya.Hickle answered on March 19th 20 at 08:52
Stand two blocks from the image. One OVER the border, the second UNDER.
zoila.Hal answered on March 19th 20 at 08:54
the designer would hands pootryvat )) Do a pseudo-element right border z-index