Define variables in media queries?

[JamesCoyle]

It seems this doesn't work but should according to the spec AFAIK. I read about it here.

@media screen and (max-width: 1280px) {
    :root {
        --total-width: 1000px;
    }
}

The above code should change the value of the --total-width variable if the media query is active. I believe when supported the browser should be able to handle this. To make it work with Myth though it would require pulling every definition where the variable is used up into the media query.