A visual aid to show you which media query is active

I've found it handy during the development of responsive CSS to know what stylesheet or media query is active.

The following is an example of how to dynamically add labels to a page.

@media screen and (max-width:600px) {
  .site-time p::after { 
    content:" (0-600px)";
  }
}

@media (min-width: 601px) and (max-width: 800px) {
  .site-time p::after { 
    content:" (601-800px)";
  }
}

I've picked an element that was in every variant of the site layout, and appended some text indicating the active sheet.