outline-offset

The outline-offset CSS property sets the amount of space between an outline and the edge or border of an element.

An outline is a line that is drawn around an element, outside the border edge. The space between an element and its outline is transparent. In other words, it is the same as the parent element’s background.

Values: <length> The width of the space between the element and its outline. A negative value places the outline inside the element. A value of 0 places the outline so that there is no space between it and the element.

Syntax example: outline-offset: 3px;