JSFiddle - React, Tailwind, and code Playground

HTML

<div id="popup">
  <div class="main">
    <a href="https://www.wikipedia.org/#">This text should be white</a>
    <a href="https://www.wikipedia.org/">This text should also be white</a>
  </div>
</div>

CSS

#popup {
  all: initial;
}

#popup * {
  all: initial;
  display: block;
}

#popup .main a {
  padding: 10px;
  background-color: #aaa;
  color: #fff;
  margin: 20px;
}

#popup .main a:visited {
  color: #fff; /* also ignored */
}