JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.20.2/codemirror.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.20.2/addon/scroll/simplescrollbars.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.20.2/codemirror.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.20.2/addon/scroll/simplescrollbars.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.20.2/mode/javascript/javascript.min.js"></script>
<script type="text/javascript">
	var myCodeMirror = CodeMirror(document.body, {
  	value: "function myScript(){return 100;}",
    mode:  "javascript",
    lineSeparator: null,
    theme: "default", // theme directory
    indentUnit: 2,
    smartIndent: true,
    tabSize: 2,
    indentWithTabs: false,
    electricChars: true,
    extraKeys: null,
    lineWrapping: false,
    lineNumbers: true,
    firstLineNumber: 1,
    scrollbarStyle: "overlay",
    inputStyle: "contenteditable",
    readOnly: false, // also "nocursor"
    showCursorWhenSelecting: false,
    lineWiseCopyCut: true,
    undoDepth: 200,
    historyEventDelay: 1250,
    autofocus: true
  });
</script>
  
 <div id="content">
   ABC
   <div id="popup">
     DEF
   </div>
 </div>

CSS

.CodeMirror {
  height: calc(100vh - 25px);
  width: 100%;
}
#content {
  cursor: pointer;
  position: relative;
}
#popup {
  display: none;
  position: absolute;
  top: 0;
  z-index: 1;
  width: 100%;
}

JavaScript

$(document).ready(function(){
    $('#content').click(
        function(){
            popup = $('#popup');
            if (popup.hasClass('show')) {
                popup.slideUp(250, function() {
                    popup.fadeOut(250).removeClass('show');
                });
            } else {
                popup.slideDown(250, function() {
                    popup.fadeIn(250).addClass('show');
                });
            };
        }
    );
});