Optimize CSS Assets safe = true

[JulienMelissas]

I was running into some issues on production builds with z-indexes as well as a few more advanced background gradients, etc. This issue linked to a solution I thought I should try which fixed it right away. By default I think this should be included in all builds.

[swalkinshaw]

Would be nice to see an example and the size difference.

[oxyc]

I've had the issue with Foundation back in Sage 8 as well. Same fix.

[JulienMelissas]

Would be nice to see an example and the size difference.

So I have 2 css files in my build, main.css and critical.css
Here's with this PR:

main: 121kb
critical: 13kb

And before:

main: 120kb
critical: 13kb

This is a production project with 99% of the code written. Not much of a difference iirc 😉

[JulienMelissas]

Oops, sorry you also said an example. On this one project in critical.css I have a z-index set to 2000 for an object that needs to be on top of EVERYTHING on the page at the beginning of the page load (in this example it's an 21+ screen for a brewery). With safe off, it transforms the z-index to 3. It also takes the background gradient animation and totally screws it up. Not exactly sure what it's doing there but I know it doesn't work. Probably a keyframe optimization thing.

[oxyc]

Related #1610 (comment)

[JulienMelissas]

@oxyc oh word! looks like this just didn't get ported over in the new Sage.