Gradient border SCSS mixin

GradientBorder.scss

@mixin gradientBorder($leftColor,$rightColor,$borderWidth)
{
   -webkit-appearance:none;
  border:none;
  background-image:linear-gradient(to right,$leftColor,$rightColor),linear-gradient(to right,$leftColor,$rightColor);
  outline:none;
  border-left:$borderWidth solid $leftColor;
  border-right:$borderWidth solid $rightColor;
  background-repeat:no-repeat;
  background-size:100% $borderWidth;
  background-color:transparent;
  background-position: 0 0, 0 100%;
}