Possible to give file-attachment link a class

When working with a page or a post and you wanna add one or more file-attachments to it, you can do so by uploading the files to the post and then insert a link where you want them to show up in your content.

For example it could look something like this (the output):

<h1>Headline of post</h1>
<p>Some random text about something... after this paragraph I will upload a PDF file and insert into post</p>
<p>
    <a href="https://www.mysite.com/wp-content/uploads/2010/10/myfile.pdf">My PDF file</a>
</p>

My problem is that my attachment link doesn’t give me anything to work with when it comes to style the it. In the above example I used a PDF file, how cool wouldn’t it be if the link got a class that said it was an attachment and a PDF file, kinda like:

<p>
    <a class="attachment pdf" href="https://www.mysite.com/wp-content/uploads/2010/10/myfile.pdf">My PDF file</a>
</p>

Well I hope you boys and girls understand what I’m looking for. Would be great if anyone know a hack or a plugin for this.

Btw: I found this post, and it worked pretty good, problem is I wanna do this and be able to choose where in my text I wanna have each of the file-attachments.

https://www.tgrayimages.com/automate-file-attachments-on-your-wordpress-posts/