Radios that belong together in HTML & CSS
HTML & CSS interview exercise on Forms, difficulty 1 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Offer a choice of plan: Free, Pro monthly and Pro yearly, as three radio buttons that belong to one group (only one can be chosen), each with a clickable label, Free selected to begin with. Group them under a legend that says Plan.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.