<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Full-Screen Text Editor</title>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.62.0/codemirror.min.css">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.62.0/codemirror.min.js"></script>
    <style>
        body, html { 
       