.list2a {
    margin-bottom: 8px;
    padding:0;
    list-style: none;
    counter-reset: li;
}    
.list2a li {
    position: relative;
    border: 2px solid #337AB7;
    background: #EBF3FA;
    padding:16px 20px 16px 28px;
    margin:12px 0 12px 40px;
    -webkit-transition-duration: 0.3s;
    transition-duration: 0.3s;
}
.list2a li:hover {
    background: #FFF;
}
.list2a li:before {
    line-height: 32px;
    position: absolute;
    top: 4px;
    left:-40px;
    width:40px;
    text-align:center;
    font-size: 16px;
    font-weight: bold;
    color: #FFF;
    background: #337AB7;
    counter-increment: li;
    content: counter(li);
    -webkit-transition-duration: 0.2s;
    transition-duration: 0.2s;
}
.list2a li:hover:before {
    width:46px;
}
.list2a li:after {
    position: absolute;
    left: 0;
    top: 4px;
    content: "";
    height: 0;
    width: 0;
    border: 16px solid transparent;
    border-left-color: #337AB7;
    -webkit-transition-duration: 0.2s;
    transition-duration: 0.2s
}
.list2a li:hover:after {
    margin-left: 6px;
}