Hi,
I use ph-css as my maven plugin to minify css now, but I facing the following error
Unexpected rule '@': Unknown rule in the middle of a rule-set is not allowed!

This happened when I use @-moz-document inside an media queries, e.g.:
@media (max-width: 959px) {
...
@-moz-document url-prefix() {
.test-class {
height: 1vh;
visibility: collapse;
}
}
}

Would you add support to this situation? thanks