Flutter and Dart as the official docs teach them — the cross-platform UI toolkit and the language underneath it. Master Dart first: sound null safety (?, !, late, required), const vs final, futures and async/await, streams, classes, mixins, and extensions, records and pattern matching, collection-if and spreads. Then Flutter's core model: everything is a widget, Stateless vs Stateful and the State lifecycle (initState, didUpdateWidget, dispose), keys and when they matter, BuildContext pitfalls, and the layout algorithm — constraints go down, sizes go up, the parent sets position — including the unbounded-height errors every beginner hits. Plus state management fundamentals (setState, InheritedWidget, and the lay of provider/riverpod/bloc), navigation, pubspec and assets, widget testing (pumpWidget, pump, pumpAndSettle), platform channels, and hot reload vs hot restart. Predict-the-output and spot-the-bug items test real understanding; every explanation names the concept, the classic confusion, and a portable rule. Authored from docs.flutter.dev and dart.dev at the current stable release. Part of the Developer track.