Is it possible to change only the Y value of background position in CSS?

Question

Is it possible to change only Y value of background position in CSS?

background-position-y is not a valid solution.

Answer 1

Only by reading (with JS) the current value of background-position (using a computed style method if it isn't set inline), parsing it to read the X value and then setting it again using the X value you just retrieved.

There is no way to say "Take the background position X value from the cascade and the Y value from this" in CSS.