Original: https://www.drweb.de/responsive-navigation-css-dropdown-menue/

Responsive Dropdown Menü angepasst für DokuWiki.

Ich habe alles in eine Datei geschrieben. Natürlich ist es sinnvoller CSS, JS und HTML zu trennen.
Die Datei header_menu.html in das Verzeichnis /conf kopieren.

Bei dieser Version ist jQuery über CDN eingebunden. Da diese Server sich im Ausland befinden würde ich wegen DSGVO die Datei local einbinden.

header_menu.html

<!-- mit CDN 
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
-->
 
<script src="lib/scripts/jquery/jquery.min.js"></script>
 
<style>
div.breadcrumbs { 
	border-top:0 !important;
	margin-bottom: 1.6em !important;
}
 
@charset "UTF-8";
.xnavi {
  height: 70px;
  background: lightgray;
}
 
.xnavi .brand {
  position: absolute;
  padding-left: 20px;
  float: left;
  line-height: 70px;
  text-transform: uppercase;
  font-size: 1.4em;
}
.xnavi .brand a,
.xnavi .brand a:visited {
  color: #ffffff;
  text-decoration: none;
}
 
.xnavi .nav-container {
  max-width: 1000px;
  margin: 0 auto;
}
 
.xnavi nav {
  float: right;
}
.xnavi nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
.xnavi nav ul li {
  float: left;
  position: relative;
}
.xnavi nav ul li a,
.xnavi nav ul li a:visited {
  display: block;
  padding: 0 20px;
  line-height: 70px;
  background: lightgray !important;
  color: black !important;
  text-decoration: none;
}
.xnavi nav li { margin:0;}
.xnavi nav ul li a:hover,
.xnavi nav ul li a:visited:hover {
  background: gray !important;
  color: #ffffff !important;
  text-decoration: none !important;
}
.xnavi nav ul li a:not(:only-child):after,
.xnavi nav ul li a:visited:not(:only-child):after {
  padding-left: 4px;
  content: " ▾";
}
.xnavi nav ul li ul li {
  min-width: 190px;
}
.xnavi nav ul li ul li a {
  padding: 15px;
  line-height: 20px;
}
 
.xnavi .nav-dropdown {
  position: absolute;
  display: none;
  z-index: 1;
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.15);
}
 
/* Mobile navigation */
.xnavi .nav-mobile {
  display: none;
  position: absolute;
  top: 0;
  right: 0;
  background: lightgray;
  height: 70px;
  width: 70px;
}
 
@media only screen and (max-width: 798px) {
  .xnavi .nav-mobile {
    display: block;
  }
 
  .xnavi nav {
    width: 100%;
    padding: 70px 0 15px;
  }
  .xnavi nav ul {
    display: none;
  }
  .xnavi nav ul li {
    float: none;
  }
  .xnavi nav ul li a {
    padding: 15px;
    line-height: 20px;
  }
  .xnavi nav ul li ul li a {
    padding-left: 30px;
  }
 
  .nav-dropdown {
    position: static;
  }
}
 
@media screen and (min-width: 799px) {
  .xnavi .nav-list {
    display: block !important;
  }
}
 
/* aktive Submenu */
.nav-list a:active, .nav-list a:focus {
text-decoration: none ;
}
.xnavi #nav-toggle {
  position: absolute;
  left: 18px;
  top: 22px;
  cursor: pointer;
  padding: 10px 35px 16px 0px;
}
.xnavi #nav-toggle span,
.xnavi #nav-toggle span:before,
.xnavi #nav-toggle span:after {
  cursor: pointer;
  border-radius: 1px;
  height: 5px;
  width: 35px;
  background: #ffffff;
  position: absolute;
  display: block;
  content: "";
  transition: all 10ms ease-in-out;
}
.xnavi #nav-toggle span:before {
  top: -10px;
}
.xnavi #nav-toggle span:after {
  bottom: -10px;
}
.xnavi #nav-toggle.active span {
  background-color: transparent;
  text-decoration: none !important;
}
.xnavi #nav-toggle.active span:before,
.xnavi #nav-toggle.active span:after {

  top: 0;
}
.xnavi #nav-toggle.active span:before {
  transform: rotate(45deg);
}
.xnavi #nav-toggle.active span:after {
  transform: rotate(-45deg);
}
 
.xnavi article {
  max-width: 1000px;
  margin: 0 auto;
  padding: 10px;
}
 
</style>
 
<script>
(function($) { // Begin jQuery
  $(function() { // DOM ready
    // If a link has a dropdown, add sub menu toggle.
    $('nav ul li a:not(:only-child)').click(function(e) {
      $(this).siblings('.nav-dropdown').toggle();
      // Close one dropdown when selecting another
      $('.nav-dropdown').not($(this).siblings()).hide();
      e.stopPropagation();
    });
    // Clicking away from dropdown will remove the dropdown class
    $('html').click(function() {
      $('.nav-dropdown').hide();
    });
    // Toggle open and close nav styles on click
    $('#nav-toggle').click(function() {
      $('nav ul').slideToggle();
    });
    // Hamburger to X toggle
    $('#nav-toggle').on('click', function() {
      this.classList.toggle('active');
    });
  }); // end DOM ready
})(jQuery); // end jQuery
</script>
 
<section class="xnavi">
  <div class="nav-container">
    <div class="brand">
      <a >Menü</a>
    </div>
    <nav>
      <div class="nav-mobile"><a id="nav-toggle" href="#!"><span></span></a></div>
      <ul class="nav-list">
        <li>
          <a href="/">Home</a>
        </li>
 
        <li>
          <a href="#!">Hobby's</a>
          <ul class="nav-dropdown">
			<li><a href="doku.php?id=ahnenforschung">Ahnenforung</a></li>
			<li><a href="doku.php?id=amateurfunk">Amateurfunk</a></li>
			<li><a href="doku.php?id=carneval">Carneval</a></li>
			<li><a href="doku.php?id=geocacheing">GEO Caching</a></li>
			<li><a href="doku.php?id=programmieren">Programmieren</a></li>
          </ul>
        </li>
 
		 <li>
          <a href="#!">Über mich</a>
          <ul class="nav-dropdown">
			<li><a href="doku.php?id=ueber_mich">Allgemein</a></li>
			<li><a href="doku.php?id=transsexualitaet">Transsexualität</a></li>
			<li><a href="doku.php?id=memoiren">Memoarien</a></li>
			<li><a href="doku.php?id=sternzeichen">Sternzeichen</a></li>
          </ul>
        </li>
 
        <li><a href="doku.php?id=kontakt">Kontakt</a></li>
 
      </ul>
    </nav>
  </div>
</section>

Es ist keine autom. Menüstruktur Erstellung. Ihr müsst die Menüpunkte mit der Hand anpassen.

Die Datei /lib/tpl/dokuwiki/tpl_headler.html anpassen.
Dazu am Ende der Datei - aber vor <!– BREADRUMBS –> folgendes einfügen:

<div class="pad group" style="z-index: 1000; clear:both; content: ''; position:relative; ">
     <?php tpl_includeFile('header_menu.html') ?>
<div>