In order to apply the z-index property to an element, you must first apply a position value of relative, absolute, or fixed. The Z-Index CSS Property: A Comprehensive Look . Here are the same boxes with position: relative added to each, and their z-index values maintained: . z- index to enhance the site's template, weaving year and date. This is because the Z-Index does not work with static positioning. Z-Index requires an element's positioning to be either fixed, relative, or absolute. Judging .