less.responsive.less

@small: ~"(max-width: 300px)";
@medium: ~"(max-width: 500px)";
// from responsive.less 
@font-size-base: 16px;

.font-size(@size) {
    @remValue: (unit(@size) / unit(@font-size-base));
    @pxValue: unit(@size);
    font-size: ~"@{pxValue}px";
    font-size: ~"@{remValue}rem";
}

.r1 {
  .font-size(18px);
  @media @medium { .font-size(16px); }
}