Question of css

Question

can we add properties to any specific character that we write throughout the code eg. # .please specify how.

Answer 1

Here you go...
https://code.sololearn.com/Wj5LktyDi9N9/?ref=app

Answer 2

No way to do it using CSS only,
need to use Javascript to do scanning.

Answer 3

so how can I do that in js