Why Doesn't My High Z-index Value Always Work?

z-index Property: In-Depth Analysis of Z-Index Values

In web development, z-index is a crucial property used to control the layering order of overlapping elements. However, developers sometimes encounter an issue where elements are displayed behind other elements despite assigning high z-index values. To understand this, it's essential to delve into the limitations and specifics of z-index values.

According to the CSS specification, z-index values can theoretically be any integers, but practical implementations may have limitations. Most browsers limit z-index values to signed 32-bit integers, ranging from -2147483648 to 2147483647.

This limitation arises from the fact that z-index values are stored as signed 32-bit integers in the browser's memory. Attempting to assign a value outside this range may result in unexpected behavior or failure. While higher z-index values are expected to display on top, there is no upper or lower limit defined in the CSS standard itself.

Therefore, if an element is being displayed behind another element despite assigning a high z-index value, it's likely that the assigned value is not within the practical range supported by the browser. In such cases, consider using alternative methods to control the layering order, such as positioning or using the CSS order property.

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