css Inner dashed border

HTML

<ul>
    <li><a>Number one</a></li>
</ul>

CSS

ul {list-style-type:none;}
li {
    padding: 10px;
    width: 180px;
    height: 30px;
    line-height: 24px;
    background-color: #dedede;
}
a {
    display: block;
    margin 4px;
    height: 26px;
    line-height: 24px;
    border: dashed 1px #363636;
}