This web app was made using the Bootstrap CSS framework. Most CSS components, browser elements, and JavaScript code should be compatible with most contemporary browsers. This version of the quiz reduces its use of JavaScript to process and evaluate results, and uses JavaScript for animations and other effects in the interface. So it should be compatible more widely.
If you notice any incompatibilities or strange browser behaviour, please let me know and I'll try and see how I can fix it.
Bootstrap as a CSS web design framework is built with a lot of accessibility features and guidance in mind, and the supporting documentation gave some guidance on what fields and metadata to populate to make page elements accessible to screen readers. I used the existing Bootstrap CSS classes and templates, and followed most existing guidance to enter metadata for html elements. This should hopefully facilitate screen readers being able to parse the page effectively. If there are any issues with this, let me know and I can make sure the page is structured in a way that is screen reader friendly.
Besides that, the colour schemes and fonts have been the standard fonts to ensure that they are legible and familiar. All links are also navigable by the keyboard alone, and this should make it a lot easier to interact with the quiz (especially when having to answer several questions).
Admittedly, this quiz is rather long. There are a lot of questions to answer. Although not all questions are mandatory, and a user need not fill in all answers in order to proceed.
Because of how I re-structured this to be a web app running on the server, the way in which I host this site has changed considerably. There may be issues with how the various ports forward to each other on the server. I will monitor this. If there are any problems with accessing this, let me know and I will try to fix it.