FAQ: CSS Display and Positioning - Z-Index


This community-built FAQ covers the “Z-Index” exercise from the lesson “CSS Display and Positioning”.

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This exercise can be found in the following Codecademy content:

Web Development

Learn CSS

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why is the value of z-index is 10 here?


The number is arbitrarily higher than zero. It could be 1, or 100, or 1000 and not matter so long as it is higher than the element we are attempting to overlap. All elements have z-index = 0 by default.


Just curious, does codecademy have the fixed and absolute positioning rules backwards? It seems like the lesson was saying when the position of an element is set to absolute it should scroll with the user(when I did it, it didn’t do that), and when it is set to fixed, it should stay fixed on the page and not go with the scroll(which is what happened when I scrolled). I don’t know if I misunderstood the article or if the developers got it wrong. Who knows?