What are the Minimum and Maximum Z-Index Values in CSS and Why Do They Matter?

Z-Index Minimum and Maximum Values in CSS

In HTML, it's possible to encounter an issue where a DIV is hidden behind other elements despite having a high z-index value.

Why is This Happening?

CSS lacks explicit minimum or maximum values for the z-index property, so the browser handles it as follows:

• Integers Accepted: Z-index values can be positive or negative integers, including zero.
• Real Numbers Disallowed: Fractional (real) numbers are not accepted as valid z-index values.
• Browser Limitations: Browsers may limit z-index values to signed 32-bit integers, ranging from -2147483648 to 2147483647.

Solution:

To resolve the issue described in the HTML, ensure that:

• The z-index value for the DIV is a valid integer.
• The value is sufficiently high compared to other elements on the page.
• Other properties like position are set correctly (e.g., absolute or relative).
• Check that the DIV's parent element has a stacking context (e.g., position: relative or transform: translateZ(0)).

The above is the detailed content of What are the Minimum and Maximum Z-Index Values in CSS and Why Do They Matter?. For more information, please follow other related articles on the PHP Chinese website!