[data-collapse] a {
  background: url("../images/arrow.png") 15px 13px no-repeat;
  display: block;
  padding: 10px;
  padding-left: 32px;
  margin: 0;  
  text-decoration: none;
  border-top: 1px solid #C5C5C5;
  border-bottom: 1px solid #C5C5C5;
}

[data-collapse] .open a { 
	background-position: 13px -25px;
  border-bottom: 0px; 
}