A simple highlightjs plugin to add a fullscreenscreen button to your code blocks.
<html>
<head>
<!-- Highlightjs -->
<link rel="stylesheet" href="static/css/default.min.css" />
<script src="static/js/highlight.min.js"></script>
<!-- Highlightjs-Fullscreen -->
<link rel="stylesheet" href="static/css/highlightjs-fullscreen.css" />
<script src="static/js/highlightjs-fullscreen.js"></script>
<!-- optional, Highlightjs-Copy (https://github.com/arronhunt/highlightjs-copy) -->
<link rel="stylesheet" href="static/css/highlightjs-copy.min.css" />
<script src="static/js/highlightjs-copy.min.js"></script>
</head>
<body>
<pre class="border">
<code style="display: block; max-height: 30em; overflow: auto;" class="language-json">
{"output": "Hello World"}
</code>
</pre>
<script>
// Enable Copy plugin (https://github.com/arronhunt/highlightjs-copy)
hljs.addPlugin(new CopyButtonPlugin());
// Enable FullScreen plugin
hljs.addPlugin(new FullscreenButtonPlugin());
// highlight all
hljs.highlightAll();
</script>
</body>
</html>