Twelve explained decisions about component contracts, forms, styling, feature probes, testing, and fallback retirement. Choose one answer and inspect the explanation before testing the related contract.
Related lessons
Custom Element Upgrade and Reconnection; Shadow Slots, Events, and Focus Contracts; Form-Associated Custom Controls and Native Fallback; Shadow Style Tokens, Parts, and Shared Sheets; Feature Probes and Functional Fallbacks; Polyfill Cost and Target Browser Policy; Cross-Browser Input and Device Contracts; Capability Rollout and Fallback Retirement.