Fix media queries in Safari.

Safari doesn’t seem to support screen queries any more.

Author: gskinner

dev/sass/mobile.scss

@@ -1,5 +1,5 @@
 // keep synced with RegExr._initUI:
-@media only screen and (max-width: 900px) {
+@media (max-width: 900px) {
 	body {
 		//font-size: 14px;