mixins.styl

placeholder(color)
  &::-webkit-input-placeholder
    color color
  &:-moz-placeholder
    color color
  &::-moz-placeholder
    color color
  &:-ms-input-placeholder
    color color

xs()
  @media screen and (max-width: 567px)
    {block}

sm()
  @media screen and (max-width: 767px)
    {block}

md()
  @media screen and (max-width: 991px)
    {block}

lg()
  @media screen and (max-width: 1299px)
    {block}
    
xl()
  @media screen and (min-width: 1300px)
    {block}
    
max($width)
  @media (max-width $width)
    {block}
    
min($width)
  @media (min-width $width)
    {block}