Tab order is the DOM, read one block at a time
Your tab order isn't your visual layout. It's your DOM in source order, and Tab visits every control inside a container before it reaches anything after it.
Topic
Accessibility
4 articles
What it took to retrofit accessibility onto a shipped app
WAVE, axe, NVDA, VoiceOver, 400% zoom and a codebase scanner, run against an app that already thought it was accessible. What each one caught.
Contrast is measured, and your borders have to pass it too
#767676 on white passes at 4.54:1 and #777777 fails at 4.47:1. Contrast as a number instead of a judgment, and the criterion covering borders and focus rings.
What you give up when you use a div instead of a button
A clickable div and a real button look identical. Here is every behavior the browser stops handing you, and what it costs to write back.