Love this idea, thanks @rootsh3ll, @Johani
There is apparently a CSS filter for this:
as in:
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
But looks like support is patchy! Browser support (surprisingly Chrome doesn’t support it ootb)?:
This works in Safari (!). Thanks to @Johani for pointing out the naughty space in my original code snippet