$breakpoint-s: 800px;
$breakpoint-m: 1000px;
$breakpoint-l: 1200px;

$screen-m-and-up: "only screen and (min-width : #{$breakpoint-s + 1})";
$screen-l-and-up: "only screen and (min-width : #{$breakpoint-m + 1})";
$screen-s-and-down: "only screen and (max-width : #{$breakpoint-s})";
$screen-m-and-down: "only screen and (max-width : #{$breakpoint-m})";
$screen-m-only: "only screen and (min-width : #{$breakpoint-s + 1}) and (max-width : #{$breakpoint-m})";