$shadow-key-umbra-opacity: 0.2 !default;
$shadow-key-penumbra-opacity: 0.14 !default;
$shadow-ambient-shadow-opacity: 0.12 !default;


@mixin shadow-1dp() {
  box-shadow: 0 1px 1px 0 rgba(0, 0, 0, $shadow-key-penumbra-opacity),
              0 2px 1px -1px rgba(0, 0, 0, $shadow-key-umbra-opacity),
              0 1px 2px 0 rgba(0, 0, 0, $shadow-ambient-shadow-opacity);
}

@mixin shadow-2dp() {
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, $shadow-key-penumbra-opacity),
              0 3px 1px -2px rgba(0, 0, 0, $shadow-key-umbra-opacity),
              0 1px 5px 0 rgba(0, 0, 0, $shadow-ambient-shadow-opacity);
}

@mixin shadow-4dp() {
  box-shadow: 0 4px 5px 0 rgba(0, 0, 0, $shadow-key-penumbra-opacity),
              0 1px 10px 0 rgba(0, 0, 0, $shadow-ambient-shadow-opacity),
              0 2px 4px -1px rgba(0, 0, 0, $shadow-key-umbra-opacity);
}