.billforsnav a { 
  color: black; 
  float: left;  
  font-size: 1.5em; 
  width: 100%;
  padding-top: 5px;
  padding-bottom: 5px;
  border-top: #ddd 4px solid;
  text-align: center;
  text-decoration: none;
  box-sizing: border-box;
}
.billforsnav .active {
  background: #bbb;
}
.billforsnav a:hover { background: #ddd; }