JSFiddle - React, Tailwind, and code Playground

HTML

<span class="b" style="border-width:5px;">Element with border-width as inlinestyle</span>
<br />
<br />
<span class="be">Element with border-width in css file</span>
<br />
<br />
<span class="b">Element just with border</span>

CSS

span.be {border:5px solid #000;border-width:5px;}
span.b {border:5px solid #000;}

JavaScript

$('span').filter(':not(.aniBorder)').hover(function(){
    $(this).stop().animate({borderWidth:10},1500);
},function(){
    $(this).stop().animate({borderWidth:5},200);
});