<!DOCTYPE html>
<!--
    Error 504: Gateway Timeout
    Description: The gateway has timed out
-->
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="robots" content="noindex, nofollow"/>
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>504 - Gateway Timeout</title>
    <style>
        html, body {
            margin: 0;
            background-color: #222;
            color: #aaa;
            font-family: 'Hack', monospace;
            font-size: 0;
        }

        .full-height {
            height: 100vh;
        }

        .flex-center {
            align-items: center;
            display: flex;
            justify-content: center;
        }

        #error_text {
            font-size: 32px;
        }

        /*  */
    </style>
</head>
<body>
<div class="flex-center full-height">
    <div>
        <div id="error_text">
            <span class="source">504: <span data-l10n>Gateway Timeout</span></span>
            <span class="target"></span>
        </div>
        
    </div>
</div>

<script>
    'use strict';

    /**
     * @param {HTMLElement} $el
     */
    const Shuffle = function ($el) {
        const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890-=+<>,./?[{()}]!@#$%^&*~`\|'.split(''),
            $source = $el.querySelector('.source'), $target = $el.querySelector('.target');

        let cursor = 0, scrambleInterval = undefined, cursorDelayInterval = undefined, cursorInterval = undefined;

        /**
         * @param {Number} len
         * @return {string}
         */
        const getRandomizedString = function (len) {
            let s = '';

            for (let i = 0; i < len; i++) {
                s += chars[Math.floor(Math.random() * chars.length)];
            }

            return s;
        };

        this.start = function () {
            $source.style.display = 'none';
            $target.style.display = 'block';

            scrambleInterval = window.setInterval(() => {
                if (cursor <= $source.innerText.length) {
                    $target.innerText = $source.innerText.substring(0, cursor) + getRandomizedString($source.innerText.length - cursor);
                }
            }, 450 / 30);

            cursorDelayInterval = window.setTimeout(() => {
                cursorInterval = window.setInterval(() => {
                    if (cursor > $source.innerText.length - 1) {
                        this.stop();
                    }

                    cursor++;
                }, 70);
            }, 350);
        };

        this.stop = function () {
            $source.style.display = 'block';
            $target.style.display = 'none';
            $target.innerText = '';
            cursor = 0;

            if (scrambleInterval !== undefined) {
                window.clearInterval(scrambleInterval);
                scrambleInterval = undefined;
            }

            if (cursorInterval !== undefined) {
                window.clearInterval(cursorInterval);
                cursorInterval = undefined;
            }

            if (cursorDelayInterval !== undefined) {
                window.clearInterval(cursorDelayInterval);
                cursorDelayInterval = undefined;
            }
        };
    };

    (new Shuffle(document.getElementById('error_text'))).start();

    // 

    // 
    if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
        ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
            s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
            s.async = s.defer = true;
            s.addEventListener('load', () => p.removeChild(s));
            p.appendChild(s);
        })(document.createElement('script'), document.body);
    }
    // 
</script>
</body>
<!--
    Error 504: Gateway Timeout
    Description: The gateway has timed out
-->
</html>