A colour with a contrast check, an upload cap and a support number.
This is a live form, not a screenshot — fill it in and submit it. The code tab is the exact file that is running, read from disk at build time, so the two cannot drift.
A settings page, and a deliberate demonstration of a warning that does not block. Pale yellow on white is unreadable and perfectly legal, so minContrast says so and lets the form submit anyway. Blocking on it would be the wrong call.
Hex out, any format in, with a live WCAG ratio.
MB and MiB are different numbers, and it keeps them different.
Country selector, per-country formatting, E.164 out.
A mask that survives mid-string editing and paste.