Perspective disables position:fixed in firefox 31 - 35

Question

Today I've updated Firefox to version 31. Since then a perspective disables the fixed position of any child. It didn't happen in earlier versions of Firefox neither does it in Chrome.

              Fiddle
FF 31-35 required

Is it intended behavour or a bug? And how to avoid it?

Dragoman

There is also another issue with fixed elements in FF31. When a fixed element is inside another fixed element, the inner will behave like it were absolutely positioned. Hope there will be a new version soon... – Trodden

what if you go through the absolutely positioned children elements and manually set 'perspective:none;`? – Paloma

Answer 1

Try using this settings:

.perspective {
    width: 100%;
    height: 100px;
    position: fixed;
    perspective: 500px;
    top: 0;
}

This will make the container stay on top and be fixed.
Working Fiddle: Fiddle

Ho