sass --watch main.scss ../stylesheet.css

@import "definitions";
@import "global";
@import "frontpage";

Al iniciar el documento:

@import url("https://fonts.googleapis.com/css?family=Kreon|Bitter");

$font-title: "Kreon", "Courier New", monospace;
font-family: $font-default;

$scale-large: (
    h1: 2.961rem,
    h2: 2.2rem,
    h3: 1.2rem,
    p: 1rem,
    p-little: 0.8rem
);
...
font-size: map-get($scale-large, h2);

@mixin size($elem) {
  font-size: map-get($scale-large, $elem);
  @media (max-width: $responsive-medium) {
    font-size: map-get($scale-medium, $elem);
  }
  @media (max-width: $responsive-small) {
    font-size: map-get($scale-small, $elem);
  }
}
...
@include size(h2);