How to pull all the rules in which there is a font-size from the entire .css file and generate a separate file?

Question

css

Need to find all rules with font-size: *px; and get
.header{
font-size: 14px;
}
.wrapper{
font-size: 14px;
}
etc., i.e. discarding everything else.

Answer 1

a little barley with the css module , and it's done