index.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
        <link rel="preload" as="font" href="./fonts/ArcadeClassic.woff" type="font/woff">
        <link rel="preload" as="style" href="./styles.css">
        <link rel="stylesheet" type="text/css" href="./styles.css">
        <title>Ping Pong</title>
    </head>
    <body>
        <canvas id="mesa" draggable="false"></canvas>
        <script src="script.js"></script>

        <button id="fullscreen" onclick="fullscreen()">⛶</button>
        <script>
            function fullscreen() {
                var mesa = document.getElementById('mesa');

                if (mesa.webkitRequestFullScreen) {
                    mesa.webkitRequestFullScreen();
                } else {
                    mesa.mozRequestFullScreen();
                }
            }
        </script>

    </body>
</html>