CSS3D and WebGL

Both CSS and WebGL have their strong points, in different scenarios.
For example, HTML/CSS3D input-elements are very optimized for smartphone-users.
Here's a small performance-matrix which SearXR uses to decide which ui-technology has the best performance/UX-ratio:

scenario	HTML/CSS3D ui-elements	HTML-2-canvas ui-elements (AFRAME)	WebGL custom ui elements	Iframe (*)
smartphone AR	✓			✓
tablet AR	✓			✓
desktop 3D	✓			✓
smartphone VR		✓	✓
headset VR		✓	✓

* = only same-origin iframe's can ensure a nice UX.

NOTE: the pattern seems to be, that stereoscopic vision automatically disqualifies HTML/CSS3D.

Rule engine to the rescue

SearXR uses a tiny rule engine for feature-sensemaking.
Basically, functions only fire when certain conditions are met:

ps. click image for enlarged version