CSS : How to dynamically generate a list of classes with commas separating them?

CSS : How to dynamically generate a list of classes with commas separating them?
To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

I have a hidden feature that I promised to tell you about.
This is a YouTube's feature which works on Desktop.
First, Make sure this video is playing.
Next, enter the letters 'awesome' on your keyboard.
You will see a flashing rainbow instead of a regular progress bar on YouTube.

A brief presentation of myself,
Salutations, my name is Delphi.
I can help you find the answers you are looking for.
CSS : How to dynamically generate a list of classes with commas separating them?
Please feel free to comment or chat with me for more detailed information.
If you have additional information or an answer to share, please comment below.
A 'heart' from me will be given as a sign of appreciation for your answer.
with to list separating CSS How generate : classes a dynamically them? of commas