SASS Mixin: Full Width Pseudo Elements

fullwidth.scss

// adapted from 
// https://css-tricks.com/full-browser-width-bars/
@mixin full-width-pseudo($bg, $pos: relative) {
	/* negative offset = section padding */
  margin: 0 -30px;
  /* add back section padding value */
  padding: 0.25rem 30px;
  position: 'absolute';
  background: $bg;

	&:before, &:after {
    content: "";
    position: absolute;
    /* fill vertically */
    top: 0;
    bottom: 0;
    width: 9600px;
    right: 100%;
    background: $bg;
  }

  &:after {
    width: 320px;
    left: 100%;
    /* you're free to do something totally different here */
    background: $bg;
  }
}