How to make a styled Markdown admonition box in a GitHub Gist?

I am trying to make a Markdown admonition box such as note box, warning box for GitHub Gist. I do some search on Google I find Python markdown admonition but these admonitions don't seem to work on GitHub Gist.

I have tried following Python warning admonition But this markdown syntax doesn't work on GitHub Gist.

!!! Hello Admonition

I also tried bootstrap boxes like this but it does not have style as expected:

<div class="alert alert-danger" role="alert">
	<div class="row vertical-align">
		<div class="col-xs-1 text-center">
			<i class="fa fa-exclamation-triangle fa-2x"></i>
		</div>
		<div class="col-xs-11">
				<strong>Error:</strong> 				  
		</div>   
	</div> 
</div>

Is there any admonition syntax or HTML code method for GitHub Gist?

Use emoji to call the user attention

> :warning: **If you are using mobile browser**: Be very careful here!

Here is list of others emojis (just copy paste):

https://gist.github.com/roachhd/1f029bd4b50b8a524f3c

Or you can also use GitHub markdown:

https://gist.github.com/rxaviers/7360908

You can make a box with some bold text in by using tables, like so:

| WARNING: be careful to baz the quux before initializing the retro encabulator! |
| --- |

This renders like this:

It's a bit of an abuse of syntax, but it works. There's unfortunately no way to apply other formatting like colours, as Chris noted.

Most repositories I've been a part of use the blockquote to simulate an admonition:

> **WARNING**: Be careful, or else!

Below is an example of it being used at the top, as well as inside, a section:

In standard markdown using the UTF8 symbol this looks pretty good:

> **⚠ WARNING: Aliens are coming.**  
> A description of the colour, smell and dangerous behaviour of the aliens.

Which Renders like this: > ⚠ WARNING: Aliens are coming.
> A description of the colour, smell and dangerous behaviour of the aliens.

GitHub Flavored Markdown doesn't have anything like that and its HTML, generated or inline, is aggressively sanitized.

You'll likely have to make do with the basics, e.g.

_**Warning:** Be very careful here._

or

### Warning

Be very careful here

While not exactly an admonition, this is supported (beta tested) since May 2022, as reported by Diego Haz and described in discussion 16925

> To better highlight and separate certain information from the rest in your documentation on GitHub, we now render a special and accessible note or warning blockquote in Markdown documents. > >We are using the existing syntax for blockquote and bold text. > > The first line must be exactly as shown below.
The first letter is case sensitive. The second line can contain your content. > > This input: > > > > **Note** > > This is a note > > > **Warning** > > This is a warning > >Becomes: > >

Warning: the syntax might still evolve and is debated in the discussion. For instance, Brenton M. Wiernik comments:

> In addition to syntax issues and semantic web problems raised by others, I am also concerned about this introducing a major incompatibility between GitHub-Flavored Markdown and pandoc markdown or CommonMark.
> > A large number of R developers write READMEs and other documentation in RMarkdown, which is generally processed using pandoc.
> > This change would mean that users would be unable to get consistent rendering with the same syntax when their package documentation is displayed on GitHub vs elsewhere. > > Overloading the blockquote in this way creates an opaque difference in the meaning of syntax across markdown flavors that is very difficult to write around for developers.

You can this alerts in your md file

https://squidfunk.github.io/mkdocs-material/reference/admonitions/#supported-types

A simple highlighted warning can be achieved like this:

>[!WARNING]
>This is a warning

This is what it looks like: