Answers for "margin bottom not working"

margin-top not working

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

margin bottom not working

// 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:

 a{
  display: block;
 }