I updated the forum. Thanks to the no-support design of this lovely FOSS forum, I have to redo the theme from scratch every time they decide to rearrange the theme format.

// ==UserScript==
// @name          Hydrogenaudio
// @description   Slightly improve the looks and usability of current HA
// @version       1.0
// @namespace     https://hydrogenaud.io
// @include       https://hydrogenaud.io/*
// @run-at        document-start
// @grant         none
// @noframes
// ==/UserScript==

(function(){
  var css = `
    #forumtitle a, #forumtitle a:link, #forumtitle a:hover {
      padding: 0 !important;
      margin: 0 !important;
      border: 0 !important;
    }
    body {
      color: #000 !important;
    }
    #top_section {
      border: #555 !important;
      border-top: 1px solid !important;
      border-bottom: 1px solid !important;
      border-radius: 0 !important;
      background: #fafafa !important;
      box-shadow: none !important;
    }
    #footer_section {
      border-top: 1px solid #555 !important;
      box-shadow: none !important;
    }
    #footer_section a, #footer_section a:link, #footer_section a:hover, #footer_section a:visited {
      color: #bbb !important;
    }
    #wrapper {
      border: 1px solid #555 !important;
      border-radius: 0 !important;
      box-shadow: none !important;
    }
    .wrapper {
      max-width: 90% !important;
    }
    a, a:link, a:link, a:visited, a.new_win:link, a.new_win:visited {
      color: #000 !important;
    }
    .listlevel1 { margin: 0 !important; padding: 0 !important; }
    #menu_nav .linklevel1, #menu_nav .linklevel1:link, #menu_nav .linklevel1:visited, #menu_current_area > strong > .linklevel1 {
      color: #000 !important;
      border-color: #555 !important;
      background: #f4f4f4 !important;
    }
    #menu_nav .linklevel1:hover, .listlevel1:hover .linklevel1, .linklevel2:hover, .listlevel2:hover .linklevel2, .linklevel3:hover, .listlevel3:hover .linklevel3, #menu_sidebar .linklevel1:hover, #menu_sidebar .listlevel1:hover .linklevel1 {
      color: #000 !important;
      border-color: #555 !important;
      background: #fafafa !important;
    }
    #menu_nav .linklevel1.active, .buttonlist .linklevel1.active, #collapse_button .linklevel1, .pm_indicator, .likes_indicator {
      color: #fff !important;
      border-color: #555 !important;
      background: #5176b5 !important;
    }
    #menu_nav .linklevel1.active:hover, .buttonlist .linklevel1.active:hover, .listlevel1:hover .linklevel1.active, #collapse_button .linklevel1:hover, .linklevel1:hover .pm_indicator, .listlevel1:hover .active {
      color: #fff !important;
      border-color: #555 !important;
      background: #6186c5 !important;
    }
    .linktree:last-child, .linktree:last-child::after, .linktree:last-child a, .linktree:last-child a:link, .linktree:last-child a:visited {
      color: #fff !important;
      background: #5176b5 !important;
    }
    .linktree:hover, .linktree:hover::after, .linktree:last-child:hover, .linktree-last-child:hover::after, .linktree:last-child a:hover {
      color: #fff !important;
      background: #6186c5 !important;
    }
    .category_header, .content_category .category_header {
      color: #fff !important;
      background: #5176b5 !important;
      text-shadow: none !important;
    }
    .category_header a:link, .category_header a:visited, .category_header a:hover {
      color: #fff !important;
    }
    ::selection {
      color: #fff !important;
      background: #5176b5 !important;
    }
  `;

  function addStyle(css) {
    let node=document.createElement("style");
    node.type="text/css";
    node.setAttribute("id", "custom_style");
    node.appendChild(document.createTextNode(css));
    let heads=document.getElementsByTagName("head");
    if (heads.length > 0) {
      heads[0].appendChild(node);
    } else {
      document.documentElement.appendChild(node);
    }
  }

  addStyle(css);

  function main() {
    let logo=document.getElementById("logobox");
    if (logo) {
      let link=document.createElement("a");
      link.href="/";
      link.innerHTML=logo.outerHTML;
      logo.parentNode.replaceChild(link, logo);
    }
  }

  function checkreadiness() {
    let ready=false;
    if (document.readyState === "interactive" || document.readyState === "complete") {
      ready=true;
    } else {
      let logo=document.getElementById("logobox");
      if (logo) ready=true;
    }
    if (ready) {
      main();
    } else {
      window.setTimeout(checkreadiness, 10);
    }
  }

  window.setTimeout(checkreadiness, 1);
})();

I updated the forum.

I updated the forum. Thanks to the no-support design of this lovely FOSS forum, I have to redo the theme from scratch every time they decide to rearrange the theme format. This also means that the old "dark" theme, Silence, is completely broken, even though I updated it to the latest version before giving up and removing it.

I'll have to redo the colors, and bug the developers about why they hard coded a fixed width into the forum theme even though I have it configured to 100% in the settings.

<li id="button_forum" class="listlevel1">
<a class="linklevel1" href="https://hydrogenaud.io/index.php?action=forum"><i class="icon icon-menu icon-lg " title="Forum"></i> <span class="button_title" aria-hidden="true">Forum</span></a>
	</li>

I used to be able to search by keyword within a single thread. Now, as far as I can see, it is only possible to narrow the search down to sub-boards. Did I overlook some menu item or command button? If not, is there any plan to restore the functionality or is it a permanent change?
Search by thread is extremely important, I'd dare say vital, for foobies browsing the jscript support thread, to give but one example.