mezclar para transición css
/* Mixin for transition css */
@mixin transition($for: all, $time-in: 250ms, $type: ease-in-out, $time-out: 0s) {
transition: $for $time-in $type $time-out;
-moz-transition: $for $time-in $type $time-out;
-webkit-transition: $for $time-in $type $time-out;
-o-transition: $for $time-in $type $time-out;
}
/* IE10 (the first stable version of IE to support transition)
does not require the -ms- prefix. */
Mohan Munna