Forms that feel like code
Label always above
Every field has a mono uppercase label sitting 6px above. Placeholders hint example input, never replace the field's purpose. aria-label mirrors the visible label.
Validate on blur
Don't error-color on every keystroke — it's hostile. Red on blur after the user leaves. Async success only after a verified roundtrip (DNS / lookup / verification).
Help text is the contract
Below every field is one help line — example, constraint, or unit. No help text means label + placeholder cover everything. Never let users guess.
Keyboard always works
Every control is reachable by Tab. Switches respond to Space, selects open with Enter, sliders take ← →. ⌘K focuses global search.
Loading is a state
Async fields show a warn (yellow) ring while pending — never "no feedback". OTP fields highlight as they fill. File uploads show progress bars per file.
Errors are specific
"Required" is lazy. Use "Phone must be 10 digits" or "Use a domain you own — try acme.com". Errors include the fix, not just the failure.