Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.3)
// Compass (v1.0.0.alpha.18)
// ----

%placeholder {
  color: blue;
}

@mixin dostuff($color: red){
  @extend %placeholder;
  
  @media screen and (min-width: 768px){
    color: $color;
  }
}

a {
  @include dostuff(yellow);
  @media screen and (min-width: 768px){
    color: orange;
  }
}

SassMeister-output.css

a {
  color: blue;
}

@media screen and (min-width: 768px) {
  a {
    color: yellow;
  }
}
@media screen and (min-width: 768px) {
  a {
    color: orange;
  }
}