I made a userscript that allows the user to toggle the visibility of the sidebar:
// ==UserScript==
// @name Toggle the right sidebar
// @version 0.1
// @author double-beep
// @include /^https://(?:[^/]+\.)?(?:(?:stackoverflow|serverfault|superuser|stackexchange|askubuntu|stackapps)\.com|mathoverflow\.net)/questions/\d+/
// @updateURL https://github.com/double-beep/my-userscripts/raw/master/toggleSidebar.user.js
// @grant none
// ==/UserScript==
(function($) {
$('#question-header').append('<a id="hide-sidebar" style="left: calc(-123px + 100%); top: 61px; position: absolute;">Hide sidebar >></a>');
const sidebar = $('#sidebar'), mainbar = $('#mainbar');
$('#hide-sidebar').click(function() {
if (sidebar.is(':visible')) {
sidebar.hide(200);
mainbar.animate({'width': '100%'}, 200);
$(this).html('<< Show sidebar');
} else {
sidebar.show(200);
mainbar.css('width', 'calc(-324px + 100%)');
$(this).html('Hide sidebar >>');
}
});
})(jQuery);