let inactivityTime = function() {
    let time;
    window.onload = resetTimer;
    document.onmousemove = resetTimer;
    document.onkeypress = resetTimer;
    function resetTimer() {
        clearTimeout(time);
        time = setTimeout(matrix, 2000)
    }
};
window.onload = function() {
    inactivityTime();
}


function matrix(){
    let canvasnodecreation = document.createElement('canvas')
    document.body.innerHTML=''
    document.body.appendChild(canvasnodecreation)
    var canvas = document.querySelector('canvas'),
        ctx = canvas.getContext('2d');

    canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;

    var letters = '010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101';
    letters = letters.split('');


    var fontSize = 10,
        columns = canvas.width / fontSize;


    var drops = [];
    for (var i = 0; i < columns; i++) {
        drops[i] = 1;
    }


    function draw() {
        ctx.fillStyle = 'rgba(0, 0, 0, .1)';
        ctx.fillRect(0, 0, canvas.width, canvas.height);
        for (var i = 0; i < drops.length; i++) {
            var text = letters[Math.floor(Math.random() * letters.length)];
            ctx.fillStyle = '#0f0';
            ctx.fillText(text, i * fontSize, drops[i] * fontSize);
            drops[i]++;
            if (drops[i] * fontSize > canvas.height && Math.random() > .95) {
                drops[i] = 0;
            }
        }
    }


    setInterval(draw, 33);
}