JSFiddle - React, Tailwind, and code Playground

HTML

<p>just 12 an 1234 example</p>

CSS

body{
    font-family: Arial;
    color: blue;
}

.number {
   font-family: Verdana;
    color: red;
}

JavaScript

$('p').html(function(i, v){
    return v.replace(/(\d)/g, '<span class="number">$1</span>');
});