Discussion on: Why you should stop z-index:9999

[Vesa Piittinen]

I've worked on two complex sites and you should survive with less than 10. The need for some occur with modals and navigation layers, and with content you need a couple for elements that popup on top of other content (but should obviously not go on top of navigation and modal layers).

Also, as CSS has advanced the need for z-index tricks has become a rarer thing.

So even for a complex layout something like this should be near the maximum required:

:root {
    --zContentLayout: 1;
    --zPopupOverlay: 2;
    --zPopupLayout: 3;
    --zNavOverlay: 4;
    --zNavLayer: 5;
    --zModalOverlay: 6;
    --zModalLayer: 7;
}

And even these can be compacted if DOM structure is well maintained, but that is not a guarantee when working on a site with a lot of contributions.