Thanks for the feedback @Foresthillnick and @RachaelDunlop.
I’ll have a fiddle in the database and see if I can get the banner back for you. In the meantime, if you open a private browsing window you’ll see the banner again.
I hear what you’re saying about the size, although the banner is intended to be a “splash screen” welcome to new users which is then dismissed by them. I could make the x more prominent (and have a round semitransparent white circle behind it to make it clearer, as per example below?) [update: this is now done]
One thing that shouldn’t happen is a vertical scroll bar though. It may be, as mods, that you can see the edit button at the foot of the banner, which causes the scrollbar? (others will not see this). If not it could be that things render differently in browsers on Windows? I’ve only tried it in macOS so far.
Regarding the busy design, I’m sure there are things we can do with the graphic (or perhaps a different graphic) to make it less dominating. I’ve been playing around with some effects and I’ll post some suggestions onto this topic.
If the buttons need changing, that’s easily done.