Z-index and list items (newbie) - html

Question

I am working on a sheet music catalog. Available sheets are listed on an ordered list and when hovering on "view", a pop-up preview image shows. I noticed that as you scroll down previewing each sheet, certain elements from the < li > items below the current one can be seen through the image. I am sure this has to do with the stacking context/order or even with a missing 'position' somewhere, but I can't figure it out.
I have the scenario here: http://jsfiddle.net/4BwBX/
HTML:
<div id="SheetMusicStore">
<ol class="enlarge">
<li>
<span class="view">[ view ]</span>
<span class="preview"><img src="http://www.antonioromo.com/newsite/images/01gnw-tn.png" alt="Just Another Dusk" /><br />Just Another Dusk (Good Night Wishes)</span>
<span class="name">Just Another Dusk (Good Night Wishes)</span>
<span class="price">$3.99 BUY</span>
</li>
<li>
<span class="view">[ view ]</span>
<span class="preview"><img src="http://www.antonioromo.com/newsite/images/02gnw-tn.png" alt="My Nightlight" /><br />My Nightlight (Good Night Wishes)</span>
<span class="name">My Nightlight (Good Night Wishes)</span>
<span class="price">$3.99 BUY</span>
</li>
<li>
<span class="view">[ view ]</span>
<span class="preview"><img src="http://www.antonioromo.com/newsite/images/03gnw-tn.png" alt="Whisper of Love" /><br />Whisper of Love (Good Night Wishes)</span>
<span class="name">Whisper of Love (Good Night Wishes)</span>
<span class="price">$3.99 BUY</span>
</li>
</ol>
</div>
CSS:
/** Sheet Music Store **/
#SheetMusicStore {
width: 500px;
margin: 40px auto;
}
ol.enlarge{
margin-left:0;
font-family: 'Trebuchet MS', Helvetica, Tahoma, Arial, Sans-serif;
font-size: 1em;
color: #999;
padding: 10px 20px;
box-shadow: inset 0 2px 2px #582E58;
border-radius: 6px;
background: url(http://www.antonioromo.com/newsite/images/sheet-bg.png) repeat 0 0 scroll;
color: #AAA;
}
ol.enlarge li{
position: relative;
z-index: 0; /*resets the stack order of the list items - later we'll increase this*/
text-shadow: 0 1px 1px rgba(0, 0, 0, .6);
background: transparent url(http://www.antonioromo.com/newsite/images/sheet-item-bg.png) repeat-x bottom left scroll;
padding: 5px 0 7px 0;
list-style-position: inside;
font-size: 12px;
}
ol.enlarge img{
background-color: #eae9d4;
padding: 6px;
box-shadow: 0 0 6px rgba(132, 132, 132, .75);
border-radius: 4px;
}
ol.enlarge span.preview{
position: absolute;
left: -9999px;
background-color: #eae9d4;
padding: 10px;
font-family: 'Trebuchet MS', Helvetica, 'Droid Sans', sans-serif;
font-size: .9em;
text-align: center;
color: #495a62;
box-shadow: 0 0 20px rgba(0,0,0, .75);
border-radius: 8px;
}
ol.enlarge li:hover{
color: #EEE;
}
ol.enlarge li:hover .view{
color:#FFFFCC !important;
}
ol.enlarge .view:hover{
cursor: pointer;
}
ol.enlarge span.preview img{
padding: 2px;
background: #ccc;
}
span.view:hover ~ span.preview{
top: -300px; /*the distance from the bottom of the thumbnail to the top of the popup image*/
left: 300px; /*distance from the left of the thumbnail to the left of the popup image*/
z-index: 50;
}
ol.enlarge .price {
width: 62px;
height: 16px;
position: absolute;
top: 7px;
right: 0;
border-radius: 8px;
background: transparent url(http://www.antonioromo.com/newsite/images/buy-bg.png) repeat 0 0 scroll;
margin: 0 0 0 10px;
font-size: 10px;
text-align: center;
line-height: 16px;
text-shadow: none;
color: #BBB;
text-decoration: none;
}
ol.enlarge .price:hover {
color: #EEE;
cursor: pointer;
}
I need the preview image to be on top of anything else. Thank you in advance for your help!

Answer 1

I fixed this by removing the z-index:0; declaration from ol.enlarge li:
ol.enlarge li{
position: relative;
/*z-index: 0; */ /*resets the stack order of the list items - later we'll increase this*/
text-shadow: 0 1px 1px rgba(0, 0, 0, .6);
background: transparent url(http://www.antonioromo.com/newsite/images/sheet-item-bg.png) repeat-x bottom left scroll;
padding: 5px 0 7px 0;
list-style-position: inside;
font-size: 12px;
}
JSfiddle
Z-index is still a bit of a dark art to me, but I believe that by declaring z-index: 0 you were taking the li out of the natural stacking order (which is actually what you wanted in this case, since they merely serve as an "anchor" for your .preview images). This was causing each li to "stack" on top of each other – albeit in a different order than the normal top down flow – and that was why you the content of the li above the hovered li was visible.