Formatting code (Syntax highlighter) for snippets in ASP.Net Core MVC

Greetings sir,

The programs on the questions were decorated similarly to a real Visual Studio Editor with numbering, colors, formatting, scroll bar etc.

Also, some blog will even decorate the colors of the code like a real Visual Studio Editor.

I believe is not manually done with CSS because it will take lots and lots of time.

Please sir, give me an idea of how this is done

I really meant formatting the browser to render codes saved as plain text to look like a visual Studio editor. When it is retrieved or rendered in Asp.net core mvc.

thanks