of the GNU Lesser General Public License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns.

  Each version is given a distinguishing version number. If the
Library as you received it specifies that a certain numbered version
of the GNU Lesser General Public License "or any later version"

background-image and -size.\n\n@mixin img-retina($file-1x, $file-2x, $width-1x, $height-1x) {\n  background-image: url($file-1x);\n\n  // Autoprefixer takes care of adding -webkit-min-device-pixel-ratio and -o-min-device-pixel-ratio,\n  // but doesn't convert dppx=>dpi.\n  // There's no such thing as unprefixed min-device-pixel-ratio since it's nonstandard.\n  // Compatibility info: https://caniuse.com/css-media-resolution\n  @media only screen and (min-resolution: 192dpi), // IE9-11 don't support dppx\n...