Why is "~" not working?

This is the code: https://codepen.io/Bard-the-scripter/pen/zYeMELM
I want to create a custom cursor and it works. but when I hover over a .btn or something else, I want to scale it or increase the width. The problem is that it doesnt work. In the developer tools I can't even see that bit of code being applied.
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