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Raising Child Element Above Parent Using z-Index
In HTML, elements follow a hierarchical structure called the Document Object Model (DOM). When multiple overlapping elements exist, their z-index property determines which one is displayed on top.
Consider the following HTML code:
<div class="parent"> <div class="child"> Hello world </div> </div> <div class="wholePage"></div>
Suppose you want the "child" div to appear above the "wholePage" div. However, by default, the "parent" div's z-index affects all its child elements.
// Wrong approach .parent { z-index: 100; position: relative; } // Incorrect output: "child" is hidden behind "wholePage"
Solution:
As mentioned in the answer provided, it's impossible to set a child's z-index higher than its parent's using only CSS. However, there are two workarounds:
1. Remove z-index from Parent:
Remove the z-index property from the "parent" div:
.parent { position: relative; }
This allows the "child" div to inherit its own z-index, which can be set to be higher than "wholePage".
2. Make Sibling Instead of Child:
Instead of being a child of the "parent" div, make the "child" div a sibling of "wholePage" and set its z-index accordingly:
<div class="sibling"> <div class="child"> Hello world </div> </div> <div class="wholePage"></div>
.sibling { position: absolute; z-index: 100; } .child { position: absolute; z-index: 150; }
In this case, both "child" and "wholePage" are siblings, and the "child" div's higher z-index ensures it appears on top. Note that using "position: absolute;" instead of "position: relative;" in this context allows the child to be positioned outside its parent's flow.
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