[html] CSS z-index not working (position absolute)

I am trying to make the black div (relative) above the second yellow one (absolute). The black div's parent has a position absolute, too.

#relative {_x000D_
 position: relative;_x000D_
 width: 40px;_x000D_
 height: 100px;_x000D_
 background: #000;_x000D_
 z-index: 1;_x000D_
 margin-top: 30px;_x000D_
}_x000D_
.absolute {_x000D_
 position: absolute;_x000D_
 top: 0; left: 0;_x000D_
 width: 200px;_x000D_
 height: 50px;_x000D_
 background: yellow;_x000D_
 z-index: 0;_x000D_
}

<div class="absolute">_x000D_
    <div id="relative"></div>_x000D_
</div>_x000D_
<div class="absolute" style="top: 54px"></div>

Expected Result:

Just add the second .absolute div before the other .second div:

<div class="absolute" style="top: 54px"></div>
<div class="absolute">
    <div id="relative"></div>
</div>

Because the two elements have an index 0.

How about this?

http://jsfiddle.net/P7c9q/4/

<div class="relative">
  <div class="yellow-div"></div>
  <div class="yellow-div"></div>
  <div class="absolute"></div>
</div>

.relative{
position:relative;
}

.absolute {
position:absolute;
width: 40px;
height: 100px;
background: #000;
z-index: 1;
top:30px;
left:0px;
}
.yellow-div {
position:relative;
width: 200px;
height: 50px;
background: yellow;
margin-bottom:4px;
z-index:0;
}

use the relative div as wrapper and let the yellow div's have normal positioning.

Only the black block need to have an absolute position then.

I was struggling to figure it out how to put a div over an image like this:

No matter how I configured z-index in both divs (the image wrapper) and the section I was getting this:

Turns out I hadn't set up the background of the section to be background: white;

so basically it's like this:

<div class="img-wrp">
  <img src="myimage.svg"/>
</div>
<section>
 <other content>
</section>

section{
  position: relative;
  background: white; /* THIS IS THE IMPORTANT PART NOT TO FORGET */
}
.img-wrp{
  position: absolute;
  z-index: -1; /* also worked with 0 but just to be sure */
}

JSFiddle

You have to put the second div on top of the first one because the both have an z-index of zero so that the order in the dom will decide which is on top. This also affects the relative positioned div because its z-index relates to elements inside the parent div.

<div class="absolute" style="top: 54px"></div>
<div class="absolute">
    <div id="relative"></div>
</div>

Css stays the same.

try this code:

.absolute {
    position: absolute;
    top: 0; left: 0;
    width: 200px;
    height: 50px;
    background: yellow;

}

http://jsfiddle.net/manojmcet/ks7ds/

I solved my z-index problem by making the body wrapper z-index:-1 and the body z-index:-2, and the other divs z-index:1.

And then the later divs didn't work unless I had z-index 200+. Even though I had position:relative on each element, with the body at default z-index it wouldn't work.

Hope this helps somebody.

I was struggling with this problem, and I learned (thanks to this post) that:

opacity can also affect the z-index

div:first-child {_x000D_
  opacity: .99; _x000D_
}_x000D_
_x000D_
.red, .green, .blue {_x000D_
  position: absolute;_x000D_
  width: 100px;_x000D_
  color: white;_x000D_
  line-height: 100px;_x000D_
  text-align: center;_x000D_
}_x000D_
_x000D_
.red {_x000D_
  z-index: 1;_x000D_
  top: 20px;_x000D_
  left: 20px;_x000D_
  background: red;_x000D_
}_x000D_
_x000D_
.green {_x000D_
  top: 60px;_x000D_
  left: 60px;_x000D_
  background: green;_x000D_
}_x000D_
_x000D_
.blue {_x000D_
  top: 100px;_x000D_
  left: 100px;_x000D_
  background: blue;_x000D_
}

<div>_x000D_
  <span class="red">Red</span>_x000D_
</div>_x000D_
<div>_x000D_
  <span class="green">Green</span>_x000D_
</div>_x000D_
<div>_x000D_
  <span class="blue">Blue</span>_x000D_
</div>

This is because of the Stacking Context, setting a z-index will make it apply to all children as well.

You could make the two <div>s siblings instead of descendants.

<div class="absolute"></div>
<div id="relative"></div>

http://jsfiddle.net/P7c9q/3/