Edit in JSFiddle

.box {
    width: 200px;
    height: 100px;
    position: relative;
    margin-bottom: 20px;
    border: 1px solid;
}

.box span {
    position: absolute;
    background:hsla( 0, 100%, 50%, 0.5 );
}

#alpha span {
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
}

#beta span{
    left: 20px;
    top: 0px;
    right: 10px;
    bottom: -10px;
}

<div id="alpha" class="box">
    <span></span>
</div>

<div id="beta" class="box">
    <span></span>
</div>