CSS Styling Standards

The frontend uses Mantine v8 primitives + CSS Modules for page-local styling + a small global stylesheet. There is no Tailwind, no styled-components, no BEM. Don't introduce one.

Style architecture

CSS Module files in use: Compose.module.css, Grammar.module.css, Sentences.module.css, Verbs.module.css. Plain .css (not modules) is used for older pages: Database.css, Login.css, PublicationDetail.css, TranslationGame.css. Prefer Modules for any new page.

Mantine theme (current)

[theme.ts](../../../frontend/src/theme.ts) — keep changes here, not scattered in components:

• primaryColor: 'violet' (custom 10-shade palette).
• Secondary palette ocean (also 10 shades).
• primaryShade: { light: 6, dark: 8 }.
• fontFamily: native system stack (-apple-system, BlinkMacSystemFont, "Segoe UI", ...) — explicitly not Noto. Don't switch.
• headings.fontFamily: same system stack.
• defaultRadius: 'md', cursorType: 'pointer', autoContrast: true, luminanceThreshold: 0.3.

Color references in components should use Mantine tokens (c="violet.7", bg="gray.0") so theme changes propagate.

App is light-oriented

Despite the loading screen using #1a1b1e, there is no dark-mode toggle and no colorScheme: 'dark' configuration. The shipped UI is light. Don't author dark-first overrides unless we add a real toggle.

Mantine vs CSS — when to use what

• Spacing, layout, color, typography, radii, shadows: Mantine props (p, m, gap, c, bg, radius, shadow).
• Page-specific composition (a 3-column dictionary grid, a verb conjugation table): CSS Modules.
• App-shell, header, nav: [App.css](../../../frontend/src/App.css). Use class names already wired into <AppShell classNames={{ header: 'app-header', navbar: 'app-navbar' }}>.
• Inline style={{ ... }}: acceptable for one-off dynamic values; reach for a Module if it grows past ~3 declarations.

Multilingual / accented-character rules

• The native font stack renders Chuukese accents (á é í ó ú, ā ē ī ō ū) without extra config.
• Don't text-transform: uppercase Chuukese strings — it strips diacritics on some platforms. If you need visual emphasis, use weight/color.
• Word-break: Chuukese words are short; avoid word-break: break-all which breaks accent ligatures. Use overflow-wrap: anywhere only as a last resort on tight columns.
• For dictionary entries, monospace looks bad — stick with the proportional system stack.

Responsive breakpoints

Use Mantine's defaults via the visibleFrom / hiddenFrom props or theme.breakpoints rather than hand-rolled media queries. Existing custom breakpoints in [App.css](../../../frontend/src/App.css#L178) match Mantine's sm (48em) — keep alignment if you add new ones.

Accessibility

• Aim for WCAG AA. autoContrast: true plus luminanceThreshold: 0.3 handles most text-on-color cases automatically.
• Don't disable focus outlines globally. If they're ugly on a custom button, restyle them, don't hide them.
• All interactive elements get a real <button> or <a> (Mantine components do this by default).

Adding a new page's styles

// MyPage.tsx
import classes from './MyPage.module.css';
<div className={classes.grid}>...</div>

/* MyPage.module.css */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--mantine-spacing-md);
}

Use Mantine CSS variables (--mantine-color-, --mantine-spacing-, --mantine-radius-*) inside Module files instead of hard-coded values — they re-theme automatically.

Pitfalls

• Loading the Mantine CSS imports after index.css reorders the cascade and breaks several components — keep the order in [main.tsx](../../../frontend/src/main.tsx).
• @mantine/notifications and @mantine/dropzone need their own CSS imports; both are already wired up. Adding @mantine/charts (or any other Mantine sub-package) requires adding its styles.css import too.
• Don't import a CSS Module from a non-page component without prefixing class names — names get hashed but :global leaks if used carelessly.
• ModalsProvider is not currently mounted in main.tsx. If you start using @mantine/modals's imperative API (modals.open(...)), wire the provider first.