Lesson Practice
Every exercise and find-the-bug challenge that belongs to a lesson. Preparing for interviews instead? Browse the interview questions.
Learn HTML from the original HTML5andCSS3.org tutorial chapters, A complete step‑by‑step HTML tutorial with interactive examples and live Try‑It editor.
Learn CSS from first principles through modern layout, responsive components, accessible interfaces, animation, performance, and production architecture.
Learn JavaScript fundamentals including variables, functions, conditions, arrays, objects, and DOM interactions.
Learn data structures and algorithms in JavaScript — arrays, hash maps, trees, graphs, recursion and the patterns interviews actually ask about.
Learn React with function components and hooks — JSX, props, state, effects, context and custom hooks, every example runnable in the browser.
162 lessons · 1785 challenges
