JSFiddle - React, Tailwind, and code Playground

HTML

<div id="app">
  <div style="border:1px solid red;"></div>
  <codemirror id="code"></codemirror>
  <div style="border:1px solid blue;"></div>
</div>

<link rel="stylesheet" href="https://codemirror.net/lib/codemirror.css">
<script src="https://codemirror.net/lib/codemirror.js"></script>
<script src="https://codemirror.net/mode/javascript/javascript.js"></script>

CSS

#app {
    display: grid;
    grid-template-rows: 100px minmax(0, 1fr) 100px;
}

html, body, #app, #code .CodeMirror  {
    height: 100%;
    width: 100%;
    margin: 0;
}

JavaScript

CodeMirror(code,  {
        styleActiveLine: true,
        autoCloseBrackets: true,
        tabSize: 4,
        mode: 'javascript',
        lineNumbers: true,
        line: true,
        value: `function whoIsOp() {
  return "хуй";
}

console.warn('OP is:', whoIsOp());
`,
   })