hr { &.on-dark { color: lighten($black, 10%); } &.on-light { color: lighten($white, 10%); } @media (-webkit-min-device-pixel-ratio: 0.75), (min--moz-device-pixel-ratio: 0.75), (-o-device-pixel-ratio: 3/4), (min-device-pixel-ratio: 0.75), (min-resolution: 0.75dppx), (min-resolution: 120dpi), { height:0.75px; } @media (-webkit-min-device-pixel-ratio: 1), (min--moz-device-pixel-ratio: 1), (-o-device-pixel-ratio: 1), (min-device-pixel-ratio: 1), (min-resolution: 1dppx), (min-resolution: 160dpi) { height:1px; } @media (-webkit-min-device-pixel-ratio: 1.33), (min--moz-device-pixel-ratio: 1.33), (-o-device-pixel-ratio: 133/100), (min-device-pixel-ratio: 1.33), (min-resolution: 1.33dppx), (min-resolution: 213dpi) { height:1.333px; } @media (-webkit-min-device-pixel-ratio: 1.5), (min--moz-device-pixel-ratio: 1.5), (-o-device-pixel-ratio: 3/2), (min-device-pixel-ratio: 1.5), (min-resolution: 1.5dppx), (min-resolution: 240dpi) { height:1.5px; } @media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-device-pixel-ratio: 2/1), (min-device-pixel-ratio: 2), (min-resolution: 2dppx), (min-resolution: 380dpi) { height:2px; } @media (-webkit-min-device-pixel-ratio: 3), (min--moz-device-pixel-ratio: 3), (-o-device-pixel-ratio: 3/1), (min-device-pixel-ratio: 3), (min-resolution: 3dppx), (min-resolution: 480dpi) { height:3px; } @media (-webkit-min-device-pixel-ratio: 4), (min--moz-device-pixel-ratio: 4), (-o-device-pixel-ratio: 4/1), (min-device-pixel-ratio: 3), (min-resolution: 4dppx), (min-resolution: 640dpi) { height:4px; } }