margin bottom not working

1.form_head {
2    margin-top: 20px;
3    color:#58585a;
4    font-size:22px;  
5    display:block; /* Add this */ 
6}

1// Your problem is that link ("a") is an INLINE element and you cannot set margin to inlines elements. In order to make it work, you have to declare it as BLOCK element, by adding:
2
3 a{
4  display: block;
5 }