@each $prop, $abbrev in (width: w, height: h) { @each $bpname,$bpsize in $grid-breakpoints { @media (min-width: $bpsize) { @each $size, $length in $sizes { .#{$abbrev}-#{$bpname}-#{$size} { #{$prop}: $length; } .m#{$abbrev}-#{$bpname}-#{$size} { max-#{$prop}: $length; } } } } }