Add CSS element to my content (.md) post?

Trying to add some style formatted code from a css file in the .md file (blog) page. I don’t think short codes will work for me, as it’s custom CSS. Basically I’m looking how to style my blog posts.

title: "My blog 1"
date: 2018-09-12T12:52:36+06:00

Here is some code <code> some code formatted from css style sheet </code>

Why not?

The only non-shortcode way I know of is, in your config.toml, add this:

	defaultMarkdownHandler = "goldmark"
		unsafe = true

and then you can use in Markdown like <div class = "foo"><!-- content --></div>. I’d recommend shortcodes though.