Answers for "how to select element in iframe css"

how to get element in iframe using javascript

const iframe = document.getElementById("myIframe");

const iWindow = iframe.contentWindow;
const iDocument = iWindow.document;

// accessing the element
const element = iDocument.getElementsByTagName("p")[0];
element.style.color = "green";

change element in iframe

// so you got an iframe (id="myiframe"). In that page you have an element id="theprice" and you want to change its value
// from the parent page do this in your javascript:
var iframevar = document.getElementById('myiframe');
var elmnt = iframevar.contentWindow.document.getElementById("theprice");
elmnt.innerHTML = theNewPrice;