:after und :before und der z-index
HTML
<div id="target">
<div>Text to appear in front</div>
</div>
CSS
#target {
position: absolute;
background: red;
width: 200px;
height: 200px;
padding: 45px;
}
#target:before {
content: "";
position: absolute;
top: -10%;
left: -10%;
width: 110%;
height: 100%;
border-right: 1px solid black;
border-bottom: 1px solid black;
z-index: -1;
}