3D Transform z-index broken with firefox, preserve-3d not preserved
<p>3D transform in Firefox seems to have issues with z-index. It seems to me that the rendering is "ignoring" the 3D Z position, and simply uses the z-index from DOM. Interesting enough, when the visible portion is made smaller, so that only a part of the wheel is visible, the z-index is suddenly correct, although other artifacts start to appear.</p>

<p>There is this intersection bug demonstration which is bugged since 2011 in Firefox, but my circles are not intersecting - so I hope it is somehow possible.
<a href="http://jsfiddle.net/yNfQX/21/" rel="nofollow noreferrer">http://jsfiddle.net/yNfQX/21/</a></p>

<p>Firefox Bugtracker: <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=689498" rel="nofollow noreferrer">https://bugzilla.mozilla.org/show_bug.cgi?id=689498</a></p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-css lang-css prettyprint-override"><code>.perspective {
  width: 400px;
  height: 400px;
  position: relative;
  perspective: 3000px;
  display: block;
}
.dcw {
  width: 100%;
  height: 100%;
  position: absolute;
  transform-style: preserve-3d;
}
.dc {
  top: calc(50% - 44px);
  left: calc(50% - 44px);
  margin: auto;
  border-radius: 50%;
  position: absolute;
  cursor: pointer;
  transform-style: preserve-3d;
  width: 88px;
  height: 88px;
  border: 1px solid black;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="perspective"&gt;
  &lt;div class="dcw"&gt;
    &lt;div class="dc" style="background-color: rgba(255,0,0,1);transform:    rotateZ( 0deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(251,4,4,1);transform:    rotateZ( 10deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(248,7,7,1);transform:    rotateZ( 20deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(244,11,11,1);transform:    rotateZ( 30deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(241,14,14,1);transform:    rotateZ( 40deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(237,18,18,1);transform:    rotateZ( 50deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(234,21,21,1);transform:    rotateZ( 60deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(230,25,25,1);transform:    rotateZ( 70deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(227,28,28,1);transform:    rotateZ( 80deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(223,32,32,1);transform:    rotateZ( 90deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(219,36,36,1);transform:    rotateZ( 100deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(216,39,39,1);transform:    rotateZ( 110deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(212,43,43,1);transform:    rotateZ( 120deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(209,46,46,1);transform:    rotateZ( 130deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(205,50,50,1);transform:    rotateZ( 140deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(202,53,53,1);transform:    rotateZ( 150deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(198,57,57,1);transform:    rotateZ( 160deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(195,60,60,1);transform:    rotateZ( 170deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(191,64,64,1);transform:    rotateZ( 180deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(187,68,68,1);transform:    rotateZ( 190deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(184,71,71,1);transform:    rotateZ( 200deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(180,75,75,1);transform:    rotateZ( 210deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(177,78,78,1);transform:    rotateZ( 220deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(173,82,82,1);transform:    rotateZ( 230deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(170,85,85,1);transform:    rotateZ( 240deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(166,89,89,1);transform:    rotateZ( 250deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(163,92,92,1);transform:    rotateZ( 260deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(159,96,96,1);transform:    rotateZ( 270deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(155,100,100,1);transform:    rotateZ( 280deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(152,103,103,1);transform:    rotateZ( 290deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(148,107,107,1);transform:    rotateZ( 300deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(145,110,110,1);transform:    rotateZ( 310deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(141,114,114,1);transform:    rotateZ( 320deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(138,117,117,1);transform:    rotateZ( 330deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(134,121,121,1);transform:    rotateZ( 340deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
    &lt;div class="dc" style="background-color: rgba(131,124,124,1);transform:    rotateZ( 350deg ) translateX(125px) rotateX( -60deg ); "&gt;&lt;/div&gt;
  &lt;/div&gt;
&lt;/div&gt;</code></pre>
</div>
</div>
</p>

<p>JSFiddle of it:
<a href="https://jsfiddle.net/gvquf0g6/" rel="nofollow noreferrer">https://jsfiddle.net/gvquf0g6/</a></p>

<p>How it should look like (screenshot from Chrome):
<a href="https://i.stack.imgur.com/J3q3i.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/J3q3i.png" alt="How it should look like (screenshot from Chrome):"></a></p>

<p>z-index issue (screenshot from Firefox):</p>

<p><a href="https://i.stack.imgur.com/7YTaX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7YTaX.png" alt="z-index issue (screenshot from Firefox)"></a></p>

<p>Artifact issue, and working z-index with partial visible wheel (screenshot from Firefox):
<a href="https://i.stack.imgur.com/W0TbT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/W0TbT.png" alt="enter image description here"></a>
<a href="https://i.stack.imgur.com/NUz4z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NUz4z.png" alt="enter image description here"></a></p>

<p>Moving your mouse over the artifacts (missing blocks) fills them in as they should be when first rendered.</p>