Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class="box">
  Hello world
</div>

SassMeister-input.scss

// ----
// Sass (v3.4.12)
// Compass (v1.0.3)
// ----

%box {
    width: 10em;
    height: 5em;
}

.box-blue {
    @extend %box;
    background-color: blue;
}

.box-green {
    @extend %box;
    background-color: green;
}

.box-yellow{
	@extend %box;
	background-color: yellow;
}

SassMeister-output.css

.box-blue, .box-green, .box-yellow {
  width: 10em;
  height: 5em;
}

.box-blue {
  background-color: blue;
}

.box-green {
  background-color: green;
}

.box-yellow {
  background-color: yellow;
}

SassMeister-rendered.html

<div class="box">
  Hello world
</div>