Generated by SassMeister.com.

SassMeister-input-HTML.html

<header>
  <h1>This is a heading</h1>
</header>

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

h1 {
  color: #D00;
  font-size: 36px;
  margin: 0;
  padding: 0;
}
header {
  width: 100%;
  background-color: darken(#FFF, 40%);
}

SassMeister-output.css

h1 {
  color: #D00;
  font-size: 36px;
  margin: 0;
  padding: 0;
}

header {
  width: 100%;
  background-color: #999999;
}

SassMeister-rendered.html

<header>
  <h1>This is a heading</h1>
</header>