<div style="position: absolute; width: 100px; height: 100px; background-color: red; z-index: -1;"></div>
<div style="height: 50px; background-color: green; width: 100px;"></div>
<div id="target">
    <div style="display: inline-block; width: 20px; height: 20px; margin-top: -25px;"></div>
</div>
<div style="height: 50px; background-color: green; width: 100px;"></div>