[riggsdk]

I did a CSS experiment back in 2008 (before CSS allowed for backdrop-blur) that did the same'ish effect: https://webdev.andersriggelsen.dk/aero/

It works by using a fixed-position pre-blurred (with glass effects) background image: https://webdev.andersriggelsen.dk/aero/bgl.jpg

This is a lot more performant than a live gaussian blur but it of course has all the drawbacks of not allowing for a dynamic background image.

[Lorin]

I took it one step further even earlier using a Flash file as a backdrop which was able to achieve the glass effect while still being in a dynamic moveable frame. Can't recall if it used iframes, would need to dig up the code but considering the era it probably did.

[djmips]

The floating window doesn't update for me past the initial position. Windows 10 19045.5131. Chrome is up to date Version 131.0.6778.86 (Official Build) (64-bit)

[riggsdk]

That is quite strange Chrome behavior. Seems to only update it's background position when the window size changes. Looks like a Chrome bug to me! Probably some optimization effort that went wrong. I'm quite sure that it worked back in the days in Chrome.

This works as expected in Firefox.