keep in mind that the support for the `background-size` shorthand is relatively new:

[Sept 2012 for Chrome - WebKit v528](https://bugs.webkit.org/show_bug.cgi?id=27577) and [Sept 2012 for Firefox - Gecko 18.0](https://bugzilla.mozilla.org/show_bug.cgi?id=570326)

we might be okay considering these are dev pages, but it's likely something to watch out for,