SASS: Mixins
// MIXINS
// Media Query
=respond-to($device...)
@if length($device) == 1
@media screen and (max-width: nth($device, 1))
@content
@else if length($device) == 2
@media screen and (max-width: nth($device, 1) and (min-width: nth($device, 2)))
@content
// Float Grid
=grid($column, $margin)
float: left
margin-right: $margin
margin-bottom: $margin
width: ((100% - (($column - 1) * $margin)) / $column)
&:nth-child(#{column}n)
margin-right: 0