Generated by SassMeister.com.

SassMeister-input-HTML.html

<div>
  <div class="a">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
  <div class="b">
    <p>Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
  <div class="c">
    <p>Incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
  <div class="d">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
</div>

SassMeister-input.scss

// ----
// Sass (v3.3.14)
// Compass (v1.0.0)
// Breakpoint (v2.5.0)
// ----


// ======================================================
// Place in external scss file
// ======================================================
// Breakpoint wrapper to handle context when extending
$_breakpoint-context-key-at-render-time:'';
@mixin media($breakpointkeys...){
  @each $key, $value in $breakpointkeys {
    $_breakpoint-context-key-at-render-time:$key !global;
    @include respond-to($key, $no-query:false){ @content; };
    $_breakpoint-context-key-at-render-time:''   !global;
  }
};
// Extend mixins
@mixin extends(){ @content; @each $key, $value in $breakpoints { @include media($key){ @content; } } }
@mixin new-extend($name){ %#{$_breakpoint-context-key-at-render-time + $name}{ @content; } }
@mixin extend($name){ & { @extend %#{$_breakpoint-context-key-at-render-time + $name};  }  }


// ======================================================
// Styles 
// ======================================================
@import "breakpoint";
// @import "thescssabove"

$breakpoints: add-breakpoint(mobile , 0px 480px);
$breakpoints: add-breakpoint(tablet , 480px 960px);
$breakpoints: add-breakpoint(desktop, 961px);



// Create the extends 
@include extends(){
  @include new-extend(foo){ content:'foo'; }
  @include new-extend(bar){ content:'bar'; }
  @include new-extend(doh){ content:'doh'; }
  @include new-extend(doh){ content:'doh number two'; }
}


// At base level normal extend works 
.a { 
  @extend %foo; 
  @include extend(foo);
}

// Double extends work
.b {
  @extend %doh; 
  @include extend(doh);
}

// Nested
.c1 {
  @include media(mobile){
    @include extend(foo);
    @include extend(bar);
    @include extend(doh);
  }
}
.c2 {
  @include media(mobile){
    @include extend(foo);
    @include extend(bar);
    @include extend(doh);
  }
}
// Wrapped
@include media(mobile){
  .c3 {
    @include extend(foo);
    @include extend(bar);
    @include extend(doh);
  }  
}

SassMeister-output.css

.a { content: 'foo'; }

.b { content: 'doh'; }

.b { content: 'doh number two'; }

@media (min-width: 0px) and (max-width: 480px) { .c1, .c2, .c3 { content: 'foo'; }
  .c1, .c2, .c3 { content: 'bar'; }
  .c1, .c2, .c3 { content: 'doh'; }
  .c1, .c2, .c3 { content: 'doh number two'; } }

SassMeister-rendered.html

<div>
  <div class="a">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
  <div class="b">
    <p>Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
  <div class="c">
    <p>Incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
  <div class="d">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
</div>