<a href="https://css-tricks.com/pseudo-class-selectors/" target="_blank">Đây cũng là link tham khảo của mình luôn :v</a>
a:link{
  color:red;
}
a:visited{
  color:green;
}
a:hover{
  color:yellow;
}
a:active{
  color:pink;
}

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