Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.5)
// Compass (v1.0.0.alpha.18)
// ----

$mit-red: #a31f34;

.button--special,
.button {
  border-radius: 5px;
  background-image: linear-gradient(
    top,
    $mit-red,
    darken($mit-red, 40%));
}

.button--special {
  background-image: linear-gradient(
    top,
    #00f,
    darken(#00f, 40%));
}

SassMeister-output.css

.button--special,
.button {
  border-radius: 5px;
  background-image: linear-gradient(top, #a31f34, black);
}

.button--special {
  background-image: linear-gradient(top, blue, #000033);
}