JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btnStart">Start</button>




<div>
  Some text, 
    <a href="#">link<span>Hint.<br/>Second line of hint.</span></a>
  , some text, and another
  <a href="#">link<span>Hint</span></a>.
</div>

CSS

a {
    position:relative;
}
a {
    position:relative;
}

a span
{
  display:none;
}
a:hover span
{
  position:absolute;
  display:inline;
  border: 1px solid #0000FF;
  margin: 0px 0px 0px 10px;
  padding: 5px;
  color: #000000;
  background: #faffc3;
  opacity:.90;
    right:0;
    margin-right:25px;
}

JavaScript

var pause = true,
    auto_refresh = setInterval(function () {
        if (pause) return;
        $('body').append('Hello World<br/>');
    }, 2000);
    

$("#btnStart").click(function() {
    pause = !pause;
    $(this).text(pause ? 'Start' : 'Stop');
});