## Migrate twenty-ui from Emotion to Linaria
Completes the migration of all `twenty-ui` components from Emotion
(runtime CSS-in-JS) to Linaria (zero-runtime, CSS extracted at build
time).
- Replaced `@emotion/styled` with `@linaria/react` across ~170 files
- Removed all Emotion dependencies from `twenty-ui`
- Introduced a CSS custom properties-based theme system:
`themeCssVariables` where every leaf is a `var(--t-xxx)` reference,
injected onto `document.documentElement` by
`ThemeCssVariableInjectorEffect`
- No more `theme` prop threading — styled components reference
`themeCssVariables.x.y` directly at build time
- Updated `twenty-front` consumers to remove `theme={theme}` prop
passing
**Before / After:**
```tsx
// Emotion
color: ${({ theme }) => theme.font.color.primary};
padding: ${({ theme }) => theme.spacing(4)};
// Linaria
color: ${themeCssVariables.font.color.primary};
padding: ${themeCssVariables.spacing[4]};
```
### Theme architecture
Two build-time utilities produce the theme system:
- **`buildThemeReferencingRootCssVariables`** — walks the theme object
and builds a nested mirror where every leaf is a `var(--t-xxx)` string
(evaluated at build time by wyw-in-js)
- **`prepareThemeForRootCssVariableInjection`** — walks the runtime
theme and collects flat `[--css-variable-name, value]` pairs, injected
onto `document.documentElement` by `ThemeCssVariableInjectorEffect`
Both share naming conventions (`camelToKebab`, `SPACING_VALUES`,
`formatSpacingKey`) and are unit tested.
### Spacing cleanup
Spacing scale now uses integers 0–32 (generated via loop), with `0.5`
and `1.5` as the only fractional exceptions. All other fractional
spacing usages (`0.25`, `0.75`, `1.25`, `2.5`, `3.5`) were replaced with
literal pixel values across ~20 twenty-front files.
### Framer Motion integration
Linaria doesn't support `styled(motion.div)` — wrapping a motion element
with `styled()` causes the component body to be stripped at build time.
Instead, we define the styled component first, then wrap it with
`motion.create()`:
```tsx
const StyledBarBase = styled.div`
background-color: ${themeCssVariables.font.color.primary};
height: 100%;
`;
const StyledBar = motion.create(StyledBarBase);
```
### Block interpolations
Linaria doesn't support interpolations that return multiple CSS
declarations (Linaria wraps the entire block in a single `var()`,
producing invalid CSS). These were split into individual property
interpolations:
```tsx
// Emotion — single interpolation returning multiple declarations
border-left: ${({ divider, theme }) => {
const border = `1px solid ${theme.border.color.light}`;
return divider ? `border-${divider}: ${border}` : '';
}}
// Linaria — one interpolation per property
border-left: ${({ divider }) =>
divider === 'left' ? `1px solid ${themeCssVariables.border.color.light}` : 'none'};
border-right: ${({ divider }) =>
divider === 'right' ? `1px solid ${themeCssVariables.border.color.light}` : 'none'};
```
### Dynamic styles via CSS variables
When a component needs to compute styles from multiple props with
complex branching logic (e.g. `Button` combining `variant`, `accent`,
`inverted`, `disabled`, `focus`, `position`), Linaria's prop
interpolations become unwieldy. In those cases we use a
`computeDynamicStyles` function that returns a `CSSProperties` object
injected via `style={}`, referenced from the static CSS with `var()`:
```tsx
const StyledButton = styled.button`
background: var(--btn-bg);
border-color: var(--btn-border-color);
&:hover { background: var(--btn-hover-bg); }
`;
const dynamicStyles = useMemo(() => {
const s = computeButtonDynamicStyles(variant, accent, ...);
return { '--btn-bg': s.background, '--btn-hover-bg': s.hoverBackground } as CSSProperties;
}, [variant, accent, ...]);
return <StyledButton style={dynamicStyles} />;
```
### CSS var + unit concatenation
CSS custom properties can't be concatenated with unit suffixes directly
(`var(--x)px` is invalid). Values that need units use `calc()`:
```tsx
// Broken
transition: background ${themeCssVariables.animation.duration.instant}s ease;
// Fixed
transition: background calc(${themeCssVariables.animation.duration.instant} * 1s) ease;
```
# Complete color refactoring
Closes https://github.com/twentyhq/core-team-issues/issues/1779
- Updated all colors to use Radix colors with P3 color space allowing
for brighter colors
- Created our own gray scale interpolated on Radix's scale to have the
same values for grays as the old ones in the app
- Introduced dark and light colors as well as there transparent versions
- Added many new colors from radix that can be used in the tags or in
the graphs
- Updated multiple color utilities to match new behaviors
- Changed the computation of Avatar colors to return only colors from
the theme (before it was random hsl)
These changes allow the user to use new colors in tags or charts, the
colors are brighter and with better contrast. We have a full range of
color variations from 1 to 12 where before we only had 4 adaptative
colors.
All these changes will allow us to develop custom themes for the user
soon, where users can choose their accent colors, background colors and
there contrast.
Charles Bochet