.post-tag a{
  font-weight: normal;
  color:black;
  background-color:lightgray;
}
.post-tag a:before{
  border-right:8px solid lightgray;
}
.post-tag a:after{
  background-color:black;
}
.post-tag a:hover{
  font-weight: normal;
  color:white;
  background:gray;
}
.post-tag a:hover:before{
  border-right-color:gray;
}
.post-tag a:hover:after{
  background-color:white;
}