Apparently, one has to be extremely careful when editing HTML/CSS even in a regular post! I’ve just wasted almost an hour trying to figure out why my post wouldn’t ‘save to draft’. It wouldn’t do the autosave, it got stuck on saving … the little wheel just kept spinning. I’m still not sure what I’d done wrong — there were no major edits, just a few links, but removing the post and pasting it back in as pure text solved the problem.
Before I came up with that splendid idea, I’d been through the whole, tedious procedure of disabling plugins, changing browser, changing themes and so on. Nothing helped and it seemed as if my page was down at times.
Perhaps I’d missed some little < tag > somewhere, I’ll never know — in any case, after that it went swimmingly.