To illustrate my problem, i made two codepens: example uses em and example uses px.
My problem is, in the first example, where i use em unit for text-shadow. Initially i set text-shadow: 0 0 0.08em #EB509E, and then in JS, I wrote exactly the same property of text-shadow(0 0 0.08em #EB509E). So I expect there will be no animation. However, if you open the pen in the debug mode, you will see the the 0.08em goes up to a very high value and then goes down.
In the second example where I use px instead of em, it works properly.
Is there any way to fix this? Thank you!