     div.setAttribute('style', 'position: absolute; width: 0; height: 0; overflow: hidden;')
            div.innerHTML = e.target.responseText
            document.body.prepend(div)
        }
        ajax.send()
    </script>
    <script>
        if ('serviceWorker' in navigator) {
            navigator.serviceWorker.register('/ui/sw.js');
        }
        function isPWA() {
            return ["fullscreen", "standalone", "minimal-ui"].some(
                (displayMode) => window.matchMedia('(display-mode