Скачать или смотреть CSS : background-position percentage not working

CSS : background-position percentage not working
To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

I promised to reveal a secret feature to you, and now it's time to share it.
This is a YouTube's feature which works on Desktop.
First, Make sure this video is playing.
Then, type the letters 'awesome' on the keyboard.
It will change your youtube progress bar into a flashing rainbow.

Here's a brief description of who I am,
Hello, I am Delphi.
Let me help you get the answers you need to your questions.
CSS : background-position percentage not working
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percentage background-position working : not CSS