example.scss

// Variables
$bodyFontColor: black;
$bodyFontColorLight: lighten($bodyFontColor, 25%);
$titleFontColor: cornflowerblue;
$linkColor: salmon;

// Mixins
@mixin box-shadow($opacity) {
    -webkit-box-shadow: 0px 0px 10px rgba(255,0,0,$opacity);
    -moz-box-shadow: 0px 0px 10px rgba(255,0,0,$opacity);
    box-shadow: 0px 0px 10px rgba(255,0,0,$opacity);
}

body {
  font: 14px "Lucida Grande", Helvetica, Arial, sans-serif;
  width: auto;
  height: auto;
  border: 3px grey dotted;
  padding: 5px;
  a {
    color: $linkColor;
    text-decoration: none;
  &:active, &:hover {
    color: darken($linkColor, 25%);
    }
  }
  .box:first-child {
    @include box-shadow(0.5)
  }
}