1 /* media queries which are guaranteed to evaluate to true */
2 @media all and (min-width: 1px), (max-width: 1000em) { }
4 /* media queries which are guaranteed to evaluate to false */
5 @media all and (max-width: 0px), (min-width: 1000em) { }
6 @media (min-width: 20px) and (max-width: 10px) { }