The aria-labelledby attribute identifies the element (or elements) that labels the element it is applied to.| MDN Web Docs
TL;DR: Stop using the word pop-up. Instead choose a term that accurately describes the control you want. I encourage you to read my post Stop Using ‘Drop-down’, which provides the set-up for this post. Along with another term I would prefer everyone stopped using. As you embark on a design,…| Adrian Roselli
1. Introduction| drafts.csswg.org
A disclosure widget is a simple control whose sole purpose is to hide or show stuff. Native HTML has one built in via the and elements. Until recently, if you wanted to use it in modern browsers you needed to use a polyfill. In most cases it was…| Adrian Roselli
The prefers-reduced-motion CSS media feature is used to detect if a user has enabled a setting on their device to minimize the amount of non-essential motion. The setting is used to convey to the browser on the device that the user prefers an interface that removes, reduces, or replaces motion-based animations.| MDN Web Docs
HTML: The Living Standard| html.spec.whatwg.org
Open UI| open-ui.org
Screen Reader User Survey #9 Results| webaim.org
Rather than continuing to update this post (where this would have been the 6th time I made some major revisions to the text) please instead see my updated ...| www.scottohara.me
Accessibility of web content requires semantic information about widgets, structures, and behaviors, in order to allow assistive technologies to convey appropriate information to persons with disabilities. This specification provides an ontology of roles, states, and properties that define accessible user interface elements and can be used to improve the accessibility and interoperability of web content and applications. These semantics are designed to allow an author to properly convey user ...| www.w3.org