Anki Markdown Card Template - Syntax highlighting, KaTex support respects light/dark modes

template.html

<!-- FRONT CARD -->
<script type="module" src="https://cdn.jsdelivr.net/npm/zero-md@3?register"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">

<zero-md>
  <template data-append>
    <style>
      div {
        background-color: transparent !important;
      }
    </style>
  </template>
  <script type="text/markdown">
{{Front}}
  </script>
</zero-md>

<!-- BACK CARD -->
<script type="module" src="https://cdn.jsdelivr.net/npm/zero-md@3?register"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">

<zero-md>
  <template data-append>
    <style>
      div {
        background-color: transparent !important;
      }
    </style>
  </template>
  <script type="text/markdown">
{{Front}}
  </script>
</zero-md>

<hr id=answer>

<zero-md>
  <template data-append>
    <style>
      div {
        background-color: transparent !important;
      }
    </style>
  </template>
  <script type="text/markdown">
{{Back}}
  </script>
</zero-md>

<script>
(function() {
  function unescapeEntities(text) {
    return text
      .replace(/&amp;/g, '&')
      .replace(/&lt;/g, '<')
      .replace(/&gt;/g, '>')
      .replace(/&quot;/g, '"');
  }
  
  function fixMarkdownScripts() {
    document.querySelectorAll('script[type="text/markdown"]').forEach(script => {
      const original = script.textContent;
      const fixed = unescapeEntities(original);
      if (original !== fixed) {
        script.textContent = fixed;
      }
    });
  }
  
  fixMarkdownScripts();
  
  // Watch for any DOM changes (like when Anki flips cards)
  const observer = new MutationObserver(() => {
    fixMarkdownScripts();
  });
  
  observer.observe(document.body, {
    childList: true,
    subtree: true
  });
  
  // Also fix on visibility change (when card is shown/hidden)
  document.addEventListener('visibilitychange', fixMarkdownScripts);
})();
</script>

Outputs: