How to add Mermaid.js to Blogger.com with dark theme

1. Go to Blogger dashboard > Theme > Edit HTML.
2. Add these lines before </head>. Note: Please go to https://mermaid.js.org/config/usage.html to check the latest usage.

<script src='https://cdn.jsdelivr.net/npm/mermaid@11.6.0/dist/mermaid.min.js'/>
<script>
  mermaid.initialize({startOnLoad: true, theme: 'dark'});
</script>

3. Finally, the example mermaid.js code and diagram will be like below:

<div class="mermaid">
  graph TD;
    A-->B;
    A-->C;
    B-->D;
    C-->D;
</div>

graph TD; A-->B; A-->C; B-->D; C-->D;