Zen Mode

// ==UserScript==
// @name         Old zen
// @namespace    http://tampermonkey.net/
// @version      0.3
// @description  Partially restore the old zen mode
// @match        https://*.lichess.org/*
// @require      https://code.jquery.com/jquery-3.2.1.min.js
// ==/UserScript==

$(document).ready(function zenify() {
    'use strict';
    var zen = true;
    if ($('.control.icons').length) {
        if (zen) {
            $('.board_left')[0].style.visibility = 'hidden';
            $('.underboard > .center')[0].style.visibility = 'hidden';
            $('.username')[0].style.display = 'none';
            $('.username')[1].style.display = 'none';
            $('.replay')[0].style.display = 'none';
            $('#top').children().each(function() {this.style.visibility = 'hidden';});
            $('#friend_box').children().each(function() {this.style.visibility = 'hidden';});
            $('#friend_box')[0].style.opacity = 0;
        }

        $(document).bind("keypress", function (e) {
            console.log(e);
            if (e.key == "x") {
                zen = !zen;
                if (zen) {
                    $('.board_left')[0].style.visibility = 'hidden';
                    $('.underboard > .center')[0].style.visibility = 'hidden';
                    $('.username')[0].style.display = 'none';
                    $('.username')[1].style.display = 'none';
                    $('.replay')[0].style.display = 'none';
                    $('#top').children().each(function() {this.style.visibility = 'hidden';});
                    $('#friend_box').children().each(function() {this.style.visibility = 'hidden';});
                    $('#friend_box')[0].style.opacity = 0;
                } else {
                    $('.board_left')[0].style.visibility = 'visible';
                    $('.underboard > .center')[0].style.visibility = 'visible';
                    $('.username')[0].style.display = 'flex';
                    $('.username')[1].style.display = 'flex';
                    $('.replay')[0].style.display = 'block';
                    $('#top').children().each(function() {this.style.visibility = 'visible';});
                    $('#friend_box').children().each(function() {this.style.visibility = 'visible';});
                    $('#friend_box')[0].style.opacity = 1;
                }
            }
        });

        //Left side bar
        $('#site_header').bind('mouseenter', function(e) {
            $('.board_left')[0].style.visibility = 'visible';
        });
        $('#site_header').bind('mouseleave', function(e) {
            $('.board_left')[0].style.visibility = zen ? 'hidden' : 'visible';
        });

        //Player names and move history
        $('.lichess_ground').bind('mouseenter', function(e) {
            $('.username')[0].style.display = 'flex';
            $('.username')[1].style.display = 'flex';
            $('.replay')[0].style.display = 'block';
        });
        $('.lichess_ground').bind('mouseleave', function(e) {
            $('.username')[0].style.display = zen ? 'none' : 'flex';
            $('.username')[1].style.display = zen ? 'none' : 'flex';
            $('.replay')[0].style.display = zen ? 'none' : 'block';
        });

        //Crosstable
        $('.underboard').bind('mouseenter', function(e) {
            $('.underboard > .center')[0].style.visibility = 'visible';
        });
        $('.underboard').bind('mouseleave', function(e) {
            $('.underboard > .center')[0].style.visibility = zen ? 'hidden' : 'visible';
        });

        //Nav bar
        $('#top').bind('mouseenter', function(e) {
            $('#top').children().each(function() {this.style.visibility = 'visible';});
        });
        $('#top').bind('mouseleave', function(e) {
            $('#top').children().each(function() {this.style.visibility = zen ? 'hidden' : 'visible';});
        });

        //Loneliness Indicator
        $('#friend_box').bind('mouseenter', function(e) {
            $('#friend_box').children().each(function() {this.style.visibility = 'visible';});
            $('#friend_box')[0].style.opacity = 1;
        });
        $('#friend_box').bind('mouseleave', function(e) {
            $('#friend_box').children().each(function() {this.style.visibility = zen ? 'hidden' : 'visible';});
            $('#friend_box')[0].style.opacity = zen ? 0 : 1;
        });
    }
});