Question 1

What selector conventions does Fun UI Playground use?

Accepted Answer

Every challenge follows the same four rules: semantic HTML first (real ,

Question 2

Does Fun UI Playground have a live backend for real HTTP behavior?

Accepted Answer

Yes. Challenges tagged "live backend" use real HTTP behavior served by a tiny stateless API under /api, with CORS open and nothing stored — including HTTP Basic Auth, arbitrary status codes, a configurable response delay, file downloads with a real Content-Disposition header, and file upload.

Question 3

How do I speed up timer-driven challenges for CI runs?

Accepted Answer

Every timer-driven page accepts a ?delay=… query parameter to shrink its built-in waits, including Dynamic Loading, Dynamic Controls, Tooltips, Obscured Elements, Streaming Feed and Session Timeout. On the network side, /api/slow?ms=… lets you dial latency precisely.

Question 4

What are the bug-hunt pages?

Accepted Answer

The bug-hunt pages each hide an exactly-stated number of intentional bugs, defined as deviations from the spec printed on the page. You can hunt manually or write assertions against the spec and watch them fail — spoilers are gated behind a confirmation click.