z-index management

zindex.scss

// | ------------- | ------------ | ------------------------------------------ |
// | z-index range | content type | details                                    |
// | ------------- | ------------ | ------------------------------------------ |
// | < 0           | Background   |                                            |
// |               | Elements     |                                            |
// | ------------- | ------------ | ------------------------------------------ |
// | 0 - 4,999     | Main Content | Standard ad tags in place with regular     |
// |               | Standard Ads | content. Includes OBA Self Regulation      |
// |               |              | Message (CLEAR Ad Notice)                  |
// | ------------- | ------------ | ------------------------------------------ |
// | 5,000 -       | Expanding    | The entire expandable ad unit should be    |
// | 1,999,999     | Advertising  | set within this range                      |
// | ------------- | ------------ | ------------------------------------------ |
// | 2,000,000 -   | Floating     | Over The Page ads (OTP’s)                  |
// | 2,999,999     | Advertising  |                                            |
// | ------------- | ------------ | ------------------------------------------ |
// | 3,000,000 -   | Pop-up       | Chat windows, message notifications        |
// | 3,999,999     | Elements     |                                            |
// | ------------- | ------------ | ------------------------------------------ |
// | 4,000,000 -   | Non-anchored | Survey recruitment panels                  |
// | 4,999,999     | Floating     |                                            |
// |               | Elements     |                                            |
// | ------------- | ------------ | ------------------------------------------ |
// | 5,000,000 -   | Expanding    | Drop down navigation, site warnings, etc.  |
// | 5,999,999     | Site         | Only the expanding portion of navigation   |
// |               | Navigation   | elements should be included on this level. |
// |               | Elements     |                                            |
// | ------------- | ------------ | ------------------------------------------ |
// | 6,000,000 +   | Full-page    | Full-window Over-the-Page (OTP) ads and    |
// |               | Overlays     | Between-the-Page ads IF they cover page    |
// |               |              | content                                    |
// | ------------- | ------------ | ------------------------------------------ |
$z-layers: (
    "fullscreen": 9999999,
    "dialog":     10004
);

@function map-has-nested-keys($map, $keys...) {
    @each $key in $keys {
        @if not map-has-key($map, $key) {
            @return false;
        }
        $map: map-get($map, $key);
    }

    @return true;
}

@function map-deep-get($map, $keys...) {
    @each $key in $keys {
        $map: map-get($map, $key);
    }

    @return $map;
}

@function z($layers...) {
    @if not map-has-nested-keys($z-layers, $layers...) {
        @warn "No layer found for `#{inspect($layers...)}` in $z-layers map. Property omitted.";
    }

    @return map-deep-get($z-layers, $layers...);
}