Boxshadow only on one or more sides

boxshadow-only-on-side.css

.box-shadow {
    background-color: #AC92EC;
    width: 160px;
    height: 90px;
    margin-top: -45px;
    margin-left: -80px;
    position: absolute;
    top: 50%;
    left: 50%;
}
.box-shadow:after {
    content: "";
    width: 150px;
    height: 1px;
    margin-top: 88px;
    margin-left: -75px;
    display: block;
    position: absolute;
    left: 50%;
    z-index: -1;
    box-shadow: 0px 0px 8px 2px #000000;
}