.rectangle-list a{
    position: relative;
    display: block;
    padding: .4em .4em .4em .8em;
    *padding: .4em;
    margin: .5em 0 .5em 2.5em;
    background: #ddd;
    color: #444;
    text-decoration: none;
    transition: all .3s ease-out;
  }

  .rectangle-list a:hover{
    background: #eee;
  }

  .rectangle-list a:before{
    content: counter(li);
    counter-increment: li;
    position: absolute;
    left: -2.5em;
    top: 50%;
    margin-top: -1em;
    background: #fa8072;
    height: 2em;
    width: 2em;
    line-height: 2em;
    text-align: center;
    font-weight: bold;
  }

  .rectangle-list a:after{
    position: absolute;
    content: '';
    border: .5em solid transparent;
    left: -1em;
    top: 50%;
    margin-top: -.5em;
    transition: all .3s ease-out;
  }

  .rectangle-list a:hover:after{
    left: -.5em;
    border-left-color: #fa8072;
  }