Hide one side of box shadow

by kuyabiye

HTML

<div></div>

http://starikovs.com/2011/11/09/css3-one-side-shadow/

CSS

div {
    margin: 30px;
    height: 100px;
    width: 100px;
    position:relative;
    overflow: hidden;
    padding: 7px 7px 0 7px;
  }
 
  div:before {
    position: absolute; 
    content: ' '; 
    top: 7px; 
    right: 7px; 
    bottom: -7px;
    left: 7px; 
    background-color: transparent; 
    box-shadow: 0 0 5px black;
    border: 1px solid red;
  }