Bug 882140 - [calendar] progress spinner: Text is too long 

sure. `inline` & `block` are explicit, `initial` we have no idea what is the value that you're trying to set.

looking at Harly comment it looks like problem is the `margin` and `padding` values and not the `display` property.. did you try to tweak that instead? - main thing is that changes should make sense in the future to reduce the likelihood of introducing regressions.