Class on Extended Properties

Hi Comunity,

One question, how can i implement a class verifing the media screen in px the user has?
Imagine i apply on a table records on extended properties a class like:

If(max-width: 568px, "firstClass", "secondClass").
Notice that where is "max-width: 568px" i want to that parameter check my screen pixels and adopt the class i want.
how can i specify dinamicly that parameter.

Best Regards!
Andrew Tabata
I would approach it another way.
only one class, only in the css, change the class-properties depending on the size.

@media (max-width: 979px) {
    .yourClass {
       specific stuff
@media (min-width: 980px) {
    .yourClass {
       other second specific stuff