JSFiddle - React, Tailwind, and code Playground

HTML

<div class="tab">
  <button class="tablinks" onclick="openCity(event, 'London')">London</button>
  <button class="tablinks" onclick="openCity(event, 'Paris')">Paris</button>
  <button class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</button>
</div>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
  <div id="outsidediv">This div should appear no matter which tab is selected.</div>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p> 
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

<script>
function openCity(evt, cityName) {
  var i, tabcontent, tablinks;
  tabcontent = document.getElementsByClassName("tabcontent");
  for (i = 0; i < tabcontent.length; i++) {
    tabcontent[i].style.visibility = "hidden";
    tabcontent[i].style.position = "fixed";
    tabcontent[i].style.top = "-1000px";
  }
  tablinks = document.getElementsByClassName("tablinks");
  for (i = 0; i < tablinks.length; i++) {
    tablinks[i].className = tablinks[i].className.replace(" active", "");
  }
  document.getElementById(cityName).style.visibility = "visible";
  document.getElementById(cityName).style.position = "relative";
  document.getElementById(cityName).style.top = "0";
  evt.currentTarget.className += " active";
}
</script>

CSS

.tab {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
}

.tab button {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  transition: 0.3s;
  font-size: 17px;
}

.tab button:hover {
  background-color: #ddd;
}


.tab button.active {
  background-color: #ccc;
}


.tabcontent {
  visibility: hidden;
  padding: 6px 12px;
  border: 1px solid #ccc;
  border-top: none;
}

#outsidediv {
  position: fixed;
  top: 80px;
  right: 50px;
  background: pink;
  visibility: visible;
  }