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                // Strip the units from a value
@function strip-units($value) {
  @return $value / ($value * 0 + 1);

// Calculate ems from a px value
@function em($px, $base-val: 16px) {
  @if not unitless($px) {
    $px: strip-units($px);
  @if not unitless($base-val) {
    $base-val: strip-units($base-val);
  @return ($px / $base-val) * 1em;

// Managing Z-Layers & icon font names
@function z($layer: "base") {
  @if not map-has-key($z-layers, $layer) {
    @warn "No z-index found in $z-layers map for '#{$layer}'. Property omitted.";
  @return map-get($z-layers, $layer);

// Clearfix
@mixin clearfix {
  &:after {
    display: table;
    content: "";
  &:after {
    clear: both;

// Sizing
@mixin size($width, $height: $width) {
  width: $width;
  height: $height;

// Align the right way
@mixin align($horizontal: true, $vertical: true) {
  position: absolute;
  @if ($horizontal and $vertical) {
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
  } @else if ($horizontal) {
    left: 50%;
    transform: translate(-50%, 0);
  } @else if ($vertical) {
    top: 50%;
    transform: translate(0, -50%);

@mixin visual-hide() {
  border: 0;
  clip: rect(0 0 0 0); height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;

@mixin filter($opacity: 0.3, $background: #000) {
  &:before {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 100%;
    display: block;
    content: " ";
    background: $background;
    opacity: $opacity;
    transition: opacity 0.3s ease;