A Sass Mixin to add Responsiveness to a Site

responsive_mixin.sass

// Responsive Mixin

@mixin responsive($width)
  
  @if $width == 300
    @media all and (min-width:300px)
      @content
  
  @if $width == 600
    @media all and (min-width:600px)
      @content
  
  @if $width == 900
    @media all and (min-width:900px)
      @content
  
  @if $width == 1020
    @media all and (min-width:1020px)
      @content