[css-shaders] GLSL implementation defined limits

Up until this point, AFAIK, CSS you either have a feature (like 3D css) or
you don't but if you do have the feature then for the most part there
aren't too many situations where you'll run into serious limits.

In other words, while you have to worry that whether or not gradients
exist, if they do exist you can generally count on them working for all
reasonable inputs.

But that's not true with CSS shaders.  It will be very easy to create CSS
shaders that work on some hardware but not on others either by making them
too long or by exceeding other limits of the user's GPU.

WebGL leaves this up to the dev to deal with but it's a programatic API.
You can check that it failed at runtime.

CSS is generally declare and forget.

Should it be that if any CSS shader on a page does not compile that all CSS
shaders on the page should be ignored? That would at least mean that you
don't have some elements displaced and others not. You either get
everything you intended or you get your fallback, no CSSshader layout.

Of course that's problematic since CSS shaders can be changed and/or
applied on the fly

Maybe specifying some maximum limits or min spec hardware or something...?