Firefox 117 released with CSS nesting support

<a href="https:&#x2F;&#x2F;developer.chrome.com&#x2F;articles&#x2F;css-nesting&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;developer.chrome.com&#x2F;articles&#x2F;css-nesting&#x2F;</a><p>CSS nesting explained

One of the best CSS feature to be ever added in my opinion ! Also, what happens if an app ships nested CSS to some user who has not yet updated his browser ? Does the app brakes ?