## Issue summary [Screencast](https://screenshot.click/screencast_2021-10-29_16-36-23.mp4) I think this stems from some specificity that was added [here](https://github.com/Shopify/polaris-react/pull/4556/files#diff-12888031b1f0e16bf9d7ee02978c37cbdfd6b64f8912ad164ab1cc51410fd538R10) It's overriding `margin-left: spacing(none)` [here](https://github.com/Shopify/polaris-react/blob/main/src/components/Stack/Stack.scss#L103-L106) Context as to why `:not(:empty)` was added can be found [here](https://github.com/Shopify/polaris-react/issues/1890)
