slack-more-space-for-channels.js

// ==UserScript==
// @name         Slack: more space for channels
// @version      0.1
// @description  try to take over the world!
// @author       Cezary Nowak
// @match        https://app.slack.com/client/*
// @icon         https://www.google.com/s2/favicons?domain=slack.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    const style = document.createElement('style');
    style.innerText = `.p-workspace__sidebar {
    top: -40px;
    z-index: 999;
    position: absolute;
    height: 100vh;
}
.p-workspace-layout {
  overflow: visible !important;
}
`;
    document.body.appendChild(style);
})();