Looks Fine Isn't a Ratio
Guess pass or fail before the ratio math proves you wrong.
the literal contrast-ratio formula computes on screen the instant you commit your guess — accessibility stops being a plugin you trust and becomes arithmetic you can catch a plugin getting borderline-wrong on
What goes in, what comes out
Timed rounds show a UI element pair — text-on-background color or a tap target — and the learner calls pass or fail against WCAG AA before any tool weighs in. The actual contrast-ratio or target-size math computes live the instant they commit.
call pass or fail on each round within a time limit; write the reason for one flagged item
a score against the real math plus a running confidence-versus-accuracy chart showing whether the learner over-trusts their eyes on contrast specifically
round count (10/20); WCAG level (AA/AAA); category mix of color contrast, target size, and alt-text presence
free accessibility glossary page, high GEO/SEO intent + Module 'Prompting the Interface' L1 warm-up
Go deeper, elsewhere
Hand-picked public explainers and open tools that complement this one — always optional, never required, never graded.
Concepts click when you open the machinery.
Three labs are already live and free — the same hands-on style this playground brings to its module.