beta-scss/src/opacity.scss

@import "variables";

@each $name, $value in $opacities {
  .opacity\:#{$name} {
    opacity: $value;
  }
}

@each $variantName, $variantValue in $variants {
  @each $name, $value in $opacities {
    .#{$variantName}\:opacity\:#{$name}:#{$variantValue} {
      opacity: $value;
    }
  }
}