In RSD 2229 - foundation
You can type in the style tags in the head, they work, but you can't paste in the css.
It used to work, then in 2208 you could shut it down and on restart then it worked
but now it won't show up with on preview & view source, or after a save restart.

The reason is I'm testing an off canvas full screen nav and the classes aren't built into the drop list yet.
So I wanted to run it using a quick header style first.

I tried this, just with some flex styling that I pasted into the 'head' section under settings, and then two rows of images on the canvas. It didn't work within the programme (I guess pasted-in css never does), but when I previewed it in a browser, it worked fine. After saving, closing and reopening it still worked fine.