A heading outline that makes sense in HTML & CSS
HTML & CSS interview exercise on Accessibility, 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.
Mark up the outline of a help page: the page title "Help centre" (one h1), two sections "Your account" and "Billing", each with its own heading, and under Billing two sub-sections "Refunds" and "Invoices" with headings one level down. No level may be skipped, and only one h1.
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.