Comments

/* This comment will appear in the CSS output.
  This is nested beneath the comment,
  so it's part of it

// This comment will not appear in the CSS output.
  This is nested beneath the comment as well,
  so it also won't appear

At-rules and shortcuts

@mixin large-text
  color: #ff0000

@media (min-width: 600px)
  h1
    @include large-text

=large-text
  color: #ff0000

h1
  +large-text

Variables

$width: 5em
#main
  width: $width