Slack's second column (contact details, threads, etc) in fullscreen

slack-fullscreen.user.css

/* ==UserStyle==
@name         Slack fullscreen details
@namespace    https://gist.github.com/PedroHLC/78f05e1ba215d00c113c6d984d3f8fb2
@homepageURL  https://gist.github.com/PedroHLC/78f05e1ba215d00c113c6d984d3f8fb2
@updateURL    https://gist.githubusercontent.com/PedroHLC/78f05e1ba215d00c113c6d984d3f8fb2/raw/slack-fullscreen.user.css
@version      0.9.0
@license      Other
@description  Slack's second column (contact details, threads, etc) in fullscreen
@author       PedroHLC (https://pedrohlc.com)
==/UserStyle== */
@-moz-document domain("app.slack.com") {

.p-workspace__secondary_view_contents {
    position: fixed;
    width: 100vw;
    height: calc(100vh - 38px);
    z-index: 100;
    left: 0;
    top: 38px;
    right: 0 !important;
    background-color: black;
}

}