JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="postAr" id="messageB1">
    <div class="postInfo">
      fdasfads fasd fadsf adsf adsf adsf asd fasd f dfsa
    </div>
    <div class="editBtn" id="1">Edit</div>
  </div>
</div>

CSS

.container {
  margin: 0px auto;
  width: 100%;
  max-width: 550px;
  background-color: #d8dbdf;
  border-radius: 2px;
  margin-top: 50px;
  padding: 10px;
  overflow: hidden;
}

.postAr {
  padding: 20px;
  box-sizing: border-box;
  width: 100%;
  background-color: #f5f5f5;
  float: left;
  position: relative;
}

.postInfo {
  position: relative;
  width: 100%;
  float: left;
}

.editBtn {
  width: 50px;
  padding: 10px;
  background-color: red;
  float: left;
  position: relative;
  text-align: center;
  color: #ffffff;
  cursor: pointer;
}

JavaScript

$(document).ready(function() {

  $("body").on("click", ".editBtn", function() {
    var ID = $(this).attr("id");
    $('.postInfo').prop('disabled', 'true');
    var currentMessage = $("#messageB" + ID + " .postInfo").html();
    var editMarkUp = '<textarea rows="5" cols="80" id="txtmessage_' + ID + '">' + currentMessage + '</textarea><button name="ok" ">Save</button><button name="cancel">Cancel</button>';
    $("#messageB" + ID + " .postInfo").html(editMarkUp);
  });
});