JSFiddle - React, Tailwind, and code Playground

HTML

<audio id="player" src="//stream-tx3.radioparadise.com/ogg-96?1490785983" autoplay></audio>
<button id="btn">play/pause</button>

CSS

button {
  margin: 1ex;
  outline: dashed 2px green;
}
button.pause {
  margin: 1ex;
  outline: dashed 2px orange;
}

JavaScript

btn.addEventListener('click', function(){
  if (player.paused) {
    this.classList.remove('pause')
    player.play()
  } else {
    this.classList.add('pause')
    player.pause()
  }
})