html line after text

1h2 {
2    overflow: hidden;
3}
4
5h2:after {
6    content:"";
7    display: inline-block;
8    height: 0.5em;
9    vertical-align: bottom;
10    width: 100%;
11    margin-right: -100%;
12    margin-left: 10px;
13    border-top: 1px solid black;
14}