Regardless of who you think your target audience is, there is not a single good argument for excluding anyone from comfortably using software. Anything done to improve accessibility benefits everyone—if not immediately, then eventually—as we are all only temporarily able at best.
I find myself debating this point far too frequently, but nothing speaks clearer than action so this post exists as an evolving record of some of the accessibility features of this website.
16pt+ body typeType smaller than this is considered illegibile by Apple, Google, and a large percentage of the population.
AAA contrast ratioA minimum 7:1 contrast ratio is necessary to ensure people with poor eyesight can comfortably read content.
Reduced motionMotion can make some people feel unwell. Careful use and
prefers-reduced-motionquerying is important.
Reduced transparencyTransparency can help blend with the OS and add depth, but also reduce readability. Allow it to be disabled.
prefers-contrastis checked, users expect borders around buttons and a contrast ratio greater than 7:1.
ARIA rolesARIA attributes make it possible to add semantics to UI state which, in turn, helps screen readers.
Dark ModeAppearance is not just a gimmick or personal preference—in some situations, it is better UX.
SpeedSpeed is a feature. Having content load quickly makes it accessible to those on poor connections or old devices.
Screen reader supportPeople with little-to-no vision experience the web through audio. You can make this experience nice too.
Offline supportThere are many parts of the world without cell coverage. Your website or application should work there too.
Keyboard controlIt is important that people who are unable to use a pointing device can navigate via a keyboard with ease.