examples/css/positioning/z_index.html

<!DOCTYPE html>
<html>
<head>
    <title>Example: Absolute positioning 2</title>
    <style>
        div {
            width: 200px;
            height: 200px;
        }

        #box_1 {
            background: #ee3e64;
            position: absolute;
            top: 0;
            left: 0;
            z-index: 3;
        }

        #box_2 {
            background: #44accf;
            position: absolute;
            top: 0;
            right: 0;
        }

        #box_3 {
            background: #b7d84b;
            position: absolute;
            bottom: 0;
            left: 0;
        }

        #box_4 {
            background: #ebde52;
            position: absolute;
            bottom: 0;
            right: 0;
        }

        #container {
            border: 1px solid black;
            width: 300px;
            height: 300px;
            position: relative;
        }
    </style>
</head>
<body>
<div id="container">
    <div id="box_1"></div>
    <div id="box_2"></div>
    <div id="box_3"></div>
    <div id="box_4"></div>
</div>
</body>
</html>