JSFiddle - React, Tailwind, and code Playground

HTML

<div id="app">
  <div style="height:100px;border:1px solid red;"></div>
  <codemirror id="code"></codemirror>
  <div style="height:100px;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: flex;
    flex-flow: column nowrap;
    align-items: stretch;
}

#code {
    flex: 1;
    min-height: 0;
}

#code .CodeMirror {
    height: 100%;
}

html, body, #app {
    height: 100vh;
    width: 100vw;
    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());
`,
   })