css help icon

1<style>
2.help_icon{
3    width:16px;
4    height:16px;
5    line-height:16px;
6    text-align:center;
7    display:inline-block;
8    border-radius:100%;
9    font-size:14px;
10    text-decoration:none;
11    -webkit-box-shadow: inset -1px -1px 1px 0px rgba(0,0,0,0.4);
12    -moz-box-shadow: inset -1px -1px 1px 0px rgba(0,0,0,0.4);
13    box-shadow: inset -1px -1px 1px 0px rgba(0,0,0,0.4);
14    color:#000;
15    background-color:#f2cd5c;
16}
17</style>
18<a class="help_icon">?</a>