# 047 — Treat presets as full style makeovers (not just color schemes) in UI and impl

## Summary

Tickets 012 and 020 already unified the *data model* for colour schemes
and custom CSS: `src/settings.rs` stores both built-in `ColorScheme`
variants and `CssEntry` (`Imported`/`Linked`) as equally-selectable themes
via `custom_theme_id`, and the doc comment at `src/settings.rs:44` notes
ticket 020 removed the old "use as theme" vs. "always-on overlay"
distinction. However, built-in presets themselves
(`webapp/src/lib/themes.ts` `BUILTIN_THEMES`) are still defined purely as
`ThemeVars` records of `--c-*` color variables — they can only ever
restyle colors, not layout — so the underlying premise of the wishlist
("presets are literally entire style makeovers that just happen to look
like color changes") isn't actually true of the built-ins yet, and the
settings UI may still read as "pick a colour scheme, optionally add CSS on
top" rather than "pick one style, which can be as small as a palette or as
large as a full redesign."

## Scope

- Audit the settings UI (`webapp/src/lib/useSettingsPanel.ts`,
  `webapp/src/App.tsx:126` and wherever the panel is rendered) for
  language/layout that still implies "colour scheme" and "CSS" are two
  separate features, and rework it to present a single list of
  interchangeable style presets (built-in or user-provided), any of which
  may be pure-palette or a full layout override.
- Confirm/ensure a user-provided style is not constrained to variable
  overrides — i.e. an imported/linked CSS entry can target arbitrary
  selectors and restructure layout, not just override `--c-*` variables
  (verify against `generateThemeCss`/`parseThemeCss` in
  `webapp/src/lib/themes.ts` and how `CssEntry` is applied to the
  document).
- No new built-in presets need to be layout-altering; this ticket is
  about removing the artificial ceiling and the UI framing, not about
  shipping a redesigned built-in theme.

## Acceptance criteria

- Settings UI presents colour schemes and custom/imported CSS as one
  unified list of selectable "styles," with no leftover UI copy or layout
  implying they're separate concepts.
- A user-supplied CSS entry can override layout-affecting rules (not just
  color variables) and have it take effect, verified manually with a
  sample stylesheet that changes more than colors.

## Depends on

None (builds on tickets 012, 020 — already merged).