Bite-sized multiple-choice quizzes for web fundamentals — HTML, CSS, JS, TS, React, Next.js, Express, MongoDB, Socket.io — with the chunky, satisfying feel of Duolingo. Questions are authored in plain Markdown and progress is saved locally, so there's no sign-up.

Quiz content is in Vietnamese 🇻🇳.

• Duolingo-style lesson flow — 3D buttons, distinct choice states, a feedback panel that rises from the bottom, and randomized encouragement.
• Interactive Rive mascot that reacts to every answer.
• Sound + haptics — toggleable audio cues and vibration where supported.
• Markdown quizzes with server-side syntax highlighting (Shiki) and Next.js-docs–style code blocks + copy button.
• Keyboard friendly — press 1–4 to answer.
• Offline-first progress via localStorage (Zustand persist).
• SEO & share cards with next/og, sitemap, and robots.
• Accessible motion — honors prefers-reduced-motion.

Instant feedback, with the answer revealed and an explanation a tap away:

Correct	Incorrect

Next.js 16 (App Router · RSC · Partial Prerendering · React Compiler) · React 19 · TypeScript · Tailwind CSS v4 · Zustand · Rive · Shiki · Turborepo + pnpm

pnpm install
pnpm dev            # → http://localhost:3001

Requires Node ≥ 20 and pnpm. Other tasks: pnpm build, pnpm lint, pnpm type-check.

Turborepo monorepo — the app lives in apps/quizzy (an apps/admin is planned).