How to apply scss to Windows only

I have a simple css property I wish to apply only for my windows (Cordova UWP) build, ie I wish to do the following just for Windows…

ion-button { 
  max-width: 100px;

According to this documentation, I thought I could use the following…

.core ion-button {
   max-width: 100px

ie use .core for anything that is not ios or Android, but it is not picked up.

Is there anyway I can just target Windows?

Thanks in advance!