Fix media-queries to work on firefox

as per https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Media_queries#-moz-device-pixel-ratio,
the `min` is infront on firefix, and is deprecated since gecko version 16 (current is
30ish), so also adding the standard one which is `min-resolution`.
Merge pull request #1286 from omega/omega/firefox-responsive-logo

Fix media-queries to work on firefox