Useful UI/UX snippet resources

A post to compile UI/UX snippet resources, as:

Description:

With nothing but a couple of lines of CSS and a few ARIA attributes, we
managed to create CSS-powered footnotes that are accessible and do not
need any JavaScript.

Screenshoot:

Source:

Comment
From the interface perspective, an alternative is usign tooltips (it means JS) for the references.

Feel free to extend the list with more snippets…

Description:

Annotator is an open-source JavaScript library to easily add annotation functionality to any webpage.

Screenshoot:

Source:
http://annotatorjs.org

Demo:
http://annotatorjs.org/showcase.html

Comment:
This feature (unsure if exactly this library) was mentioned in a technical committee meeting as a replacement for comments in OxS tools. I like a lot the idea, but IMHO it need to be integrated in eLENS interface.

Description:

A technique to implement progressive loading of CSS working right now in Firefox/IE and compliant with Chrome and Safari.

Source:

Demo:
https://jakearchibald-demos.herokuapp.com/progressive-css/

Comment:
Firefox & Edge/IE will give you a lovely progressive render, whereas Chrome & Safari give you a white screen until all the CSS loads. The current Chrome/Safari behaviour is no worse than putting all your stylesheets in the , so you can start using this method today. Over the coming months, Chrome will move to the Edge model, and more users will get a faster render.