@function rem($multiplier) {
  $font-size: 10px;
  @return $multiplier * $font-size;
}

// Gets a color from a theme palette (the output of mat-palette).
// The hue can be one of the standard values (500, A400, etc.), one of the three preconfigured
// hues (default, lighter, darker), or any of the aforementioned prefixed with "-contrast".
//
// @param $color-map The theme palette (output of mat-palette).
// @param $hue The hue from the palette to use. If this is a value between 0 and 1, it will
//     be treated as opacity.
// @param $opacity The alpha channel value for the color.
@function mat-color($palette, $hue: default, $opacity: null) {
  // If hueKey is a number between zero and one, then it actually contains an
  // opacity value, so recall this function with the default hue and that given opacity.
  @if type-of($hue) == number and $hue >= 0 and $hue <= 1 {
    @return mat-color($palette, default, $hue);
  }

  $color: map-get($palette, $hue);
  $opacity: if($opacity == null, opacity($color), $opacity);

  @return rgba($color, $opacity);
}