Theming the midgard panels

The same six query params restyle both /login and /register. Pass them on the URL you redirect users to — there's no separate config step.

Parameters

Name	Meaning	Format	Example
`font`	font-family stack	letters, digits, spaces, commas, quotes, hyphens; ≤120 chars	`Inter,system-ui`
`fg`	text color	hex: `#rgb`, `#rgba`, `#rrggbb`, `#rrggbbaa`	`%23eeeeee`
`bg`	page background color	hex	`%23111827`
`btn`	primary button color	hex	`%237c3aed`
`radius`	card / input / button rounding (px)	integer 0–32	`10`
`title`	replaces the card heading	free text, trimmed to 60 chars	`Sign+in+to+Acme`

Example

https://midgard.fly.dev/login
  ?title=Sign+in+to+Acme
  &font=Inter,system-ui
  &bg=%23111827
  &fg=%23eeeeee
  &btn=%237c3aed
  &radius=10
  &return=https://acme.fly.dev/

Behavior

All values are strictly validated client-side; invalid input is silently dropped, so there's no HTML/CSS-injection risk.
Button text color is auto-derived from btn for contrast — no separate param needed.
When no colors are passed the panel honors the browser's prefers-color-scheme, so unstyled embeds still look native in light and dark.
Theme params are preserved on the cross-link between /login and /register, along with any ?return= you pass.
There's no css= or logo= knob. For deeper customization, iframe midgard and style the surrounding chrome.

The JSON API is documented at /docs (openapi.json).