I think there is an easier way to achieve what web developers want, without having to mess around with browser internals or circularity issues.
Currently it is not possible to make a custom property in CSS reference itself. But this could be useful for several cases, e.g. if you want to modify a number for every nesting level of the same element:
border: var(--border-width) solid red;
--border-width: calc(var(--border-width) / 2);
When it comes to responsive images there are two main topics that are handled by
Two months ago I posted about a proposal for container queries (aka element queries). This article is about an update to the syntax and an in-depth explanation of the intended browser implementation.
A “Prolyfill” or “forward polyfill” is similar to a Polyfill but instead of providing a feature which is already implemented by some browsers or part of the specification, it enables a new feature which will probably be implemented by a browser in the future. If a Prolyfill gets a great deal of attention from web developers, browser makers may think of implementing it.
In a discussion on GitHub I came up with the idea of a slightly different syntax and function for container queries which I want to explain in more detail here. Container Queries are a concept described by Mat Marquis on A List Apart as an evolution of element queries. If you want to know more about container queries in general, take a look at the RICG repositories on GitHub: container-queries, cq-demos and cq-usecases.