JSFiddle - React, Tailwind, and code Playground

HTML

<p>
    Let's go Zapata let's do it for the revolution, Zapatistas!!!   
</p>

CSS

span.highlight{
   background:#F60;
    padding:5px;
    display:inline-block;
    color:#FFF;
}

p{
   font-family:Verdana;   
}

JavaScript

jQuery.fn.highlight = function (str, className) {    
    var regex = new RegExp(str, "gi");

    return this.each(function () {
        this.innerHTML = this.innerHTML.replace(regex, function(matched) {return "<span class=\"" + className + "\">" + matched + "</span>";});
    });
};

$("p").highlight("Z","highlight");