JSFiddle - React, Tailwind, and code Playground

HTML

<td>
<span>
<a title="Back to Previous View" href="javascript:controller.navigateBack();">
<img width="11" height="13" alt="Back to Previous View" title="Back to Previous View" src="http://www.trumba.com/i/DgC4zgBAwusa93o2xKoNIHtu.gif?color=%2308799f"></a></span></td>
<button>
Toggle Margin
</button>

CSS

a[title="Back to Previous View"] img{
      display:block;
      margin-top:20px;
      background-color:pink;  /*test*/
}
img.nomargin {
  margin-top: 0 !important;
}

JavaScript

$('button').on('click', function() {
	$('img').toggleClass('nomargin')
 });