box-shadow: inset 1px 1px 0 #000, inset -1px -1px 0 #000;
{{Box-shadow border}} provides style declarations to show a visual line, similar to a border, at one or more sides of an element.
This template is useful where an element should not have a border, or uses a border already. Navboxes, in particular, use borders to give the appearance of spacing between elements.
This template should complement text, instead of taking the place of text. Color blind and visually impaired users may also only perceive the text.
Wide borders may overlap the text inside the navbox elements since the borders are drawn on the inside of the element. To avoid this overlap, increase the cell padding using value greater than the border width. For a title navbox, the default title padding is '0.25em 1em', so a "left right" border of size '2em' should be offset with between '2.25em' and '3em' padding on the left and right depending on the desired appearance.