JSFiddle - React, Tailwind, and code Playground

HTML

<div class="tp_-_box" data-tp-settings="domainId:3660907"> 
    <a href="http://www.trustpilot.com/review/www.longtiestore.com" rel="nofollow" hidden>Long Tie Store Reviews</a>

</div>
-------------------------------------------------<br>
content should move with the height of the iframe

CSS

iframe {
    width:100% !important;
}
.tp-box { /*this css rule is not transfering to the iframe*/
    width:auto !important;
}

JavaScript

(function () {
    var a = "https:" == document.location.protocol ? "https://ssl.trustpilot.com" : "http://s.trustpilot.com",
        b = document.createElement("script");
    b.type = "text/javascript";
    b.async = true;
    b.src = a + "/tpelements/tp_elements_all.js";
    var c = document.getElementsByTagName("script")[0];
    c.parentNode.insertBefore(b, c)
})();





window.onload = function () {
    if (parent) {
        var oHead = document.getElementsByTagName("head")[0];
        var arrStyleSheets = parent.document.getElementsByTagName("style");
        for (var i = 0; i < arrStyleSheets.length; i++)
        oHead.appendChild(arrStyleSheets[i].cloneNode(true));
    }
}