I had the same reaction but the weird thing is: it looked ok in FireFox..?
PS Neat website and explanations, but talking about the liquid glass as a design principle in general, I would rather ui elements in a random website not use that much of gpu for not great reasons but maybe that's my problem of not thinking different.
These are in the specification here: https://drafts.fxtf.org/filter-effects-1/#typedef-filter-url
And used by backdrop-filter here: https://drafts.fxtf.org/filter-effects-2/#BackdropFilterProp...
It works on Chromium-based browsers but it does not look great, probably needs some filtering.