CSS z-index does not take effect
I expect with the following code 'max-button' be visible but it hides behind the grid. What is wrong?
<html>
<head>
<title>Grid</title>
<style>
#sketch {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
background: transparent url(grid.gif) repeat scroll 0 0;
z-index: 0;
}
#max-button {
z-index: 9999;
}
</style>
</head>
<body>
<div id="sketch"></div>
<div id="max-button"><img src="maximize.gif"></div>
</body>
</html>
And here are the two images:
maximize.gif: alt text http://www.fr开发者_如何学运维eeimagehosting.net/uploads/8c213c4a8a.gif grid.gif: alt text http://www.freeimagehosting.net/uploads/af716eaf7d.gif
#maxbutton
needs to be absolutely positioned as well.
Explanation: the grid is taken out of the default document flow, hence the button is ending up underneath where the grid would have taken it. Absolute positioning enables z-index.
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