Zigzag

$zzheight: 10px;
$zzhalfheight: calc($zzheight / 2);
$zzthickness: 130%; // increase to make the line thicker
$zzoffset: 4px;
$zzdegree: 135deg;

@mixin zigzag($bgcolor) {
  position: relative;
  z-index: 1;

  display: block;

  height: $zzheight;

  background: $bgcolor;

  &::after,
  &::before {
    content: '';

    position: absolute;
    right: 0;
    left: 0;

    display: block;
  }

  &::before {
    top: $zzthickness;

    height: ($zzheight - $zzoffset);

    background:
      linear-gradient(-$zzdegree, $zzlinecolor $zzhalfheight, transparent 0) 0 $zzhalfheight,
      linear-gradient($zzdegree, $zzlinecolor $zzhalfheight, transparent 0) 0 $zzhalfheight;
    background-repeat: repeat-x;
    background-position: top left;
    background-size: $zzheight $zzheight;
  }

  &::after {
    top: 100%;

    height: $zzheight;

    background:
      linear-gradient(-$zzdegree, $bgcolor $zzhalfheight, transparent 0) 0 $zzhalfheight,
      linear-gradient($zzdegree, $bgcolor $zzhalfheight, transparent 0) 0 $zzhalfheight;
    background-repeat: repeat-x;
    background-position: top left;
    background-size: $zzheight $zzheight;
  }
}

.zigzag,
%zigzag {
  @include zigzag($zzbgc);
}