# v2 design tokens

The v2 UI kit is built on a small set of **numbered token scales** sourced from Radix and the "Probo Radix UI" Figma file. Every token family follows the same convention as color — a numbered scale exposed as Tailwind utilities — so the kit speaks one consistent visual language: `bg-sand-3`, `text-4`, `rounded-3`, `shadow-2`.

Theme entry: [`packages/ui/src/v2/theme.css`](../../packages/ui/src/v2/theme.css), aggregating `theme/colors.css`, `theme/typography.css`, `theme/radius.css`, `theme/shadows.css`, `theme/z-index.css`.

| Family | Utilities | Steps | Source |
|--------|-----------|-------|--------|
| Color | `bg-/text-/border-<hue>-<1–12>` | 12 | Radix Colors |
| Typography | `text-<1–9>` (+ font weights) | 9 | Radix type scale |
| Radius | `rounded-<1–6>` | 6 | Radix "Medium" radius |
| Shadow | `shadow-<1–6>`, `inset-shadow-<1–3>` | 6 / 3 | Radix elevation |
| Z-index | `z-<1–6>` | 6 | UI layer roles |
| Spacing | Tailwind native (`p-4`, `gap-2`, …) | — | not tokenized |

Each `--<family>-*` is reset to `initial` in its theme layer, so a v2 build exposes **only** the numbered scales — Tailwind's default palette, t-shirt type sizes, and `shadow-sm/md/lg` are intentionally unavailable. Use the numbered token; never reintroduce an ad-hoc value.

# Colors (Radix scale)

The v2 UI kit uses [Radix Colors](https://www.radix-ui.com/colors) 12-step scales as its color primitive. Each hue provides 12 numbered steps designed for specific use cases. Components consume these through Tailwind utility classes (`bg-sand-3`, `text-red-11`, `border-gold-7`, …).

## Available scales

| Scale | Role |
|-------|------|
| **sand** | Neutral — primary UI chrome (backgrounds, borders, text) |
| **gold** | Warm accent neutral |
| **red** | Destructive / error |
| **green** | Success / positive |
| **amber** | Warning |
| **sky** | Informational |

## Step-to-usage mapping

Every scale follows the same 12-step structure:

| Step | Use case | Tailwind example |
|------|----------|------------------|
| 1 | App background | `bg-sand-1` |
| 2 | Subtle background | `bg-sand-2` |
| 3 | UI element background | `bg-sand-3` |
| 4 | Hovered UI element background | `hover:bg-sand-4` |
| 5 | Active / selected UI element background | `bg-sand-5` |
| 6 | Subtle borders and separators | `border-sand-6` |
| 7 | UI element border and focus rings | `border-sand-7` |
| 8 | Hovered UI element border | `border-sand-8` |
| 9 | Solid backgrounds | `bg-green-9` |
| 10 | Hovered solid backgrounds | `hover:bg-green-10` |
| 11 | Low-contrast text | `text-sand-11` |
| 12 | High-contrast text | `text-sand-12` |

### Quick mental model

Three bands: **low = light/background**, **middle = borders**, **high = text/solid**.

- **1–2** → backgrounds
- **3–5** → component backgrounds (normal → hover → active)
- **6–8** → borders (subtle → default → strong)
- **9–10** → solid backgrounds (normal → hover)
- **11–12** → text (low-contrast → high-contrast)

## Choosing a color step

1. **What am I styling?**
   - Background → steps 1–5 (or 9–10 for solid fills)
   - Border → steps 6–8
   - Text / icon → steps 11–12
2. **What state?**
   - Default → lower step in the range (3, 6, 9, 11)
   - Hover → next step up (4, 7, 10)
   - Active / pressed → one more (5, 8)
3. **Which hue?**
   - Neutral UI → `sand`
   - Semantic meaning → `red` (error), `green` (success), `amber` (warning), `sky` (info)
   - Warm accent → `gold`

## Neutral vs accent

Use **sand** for all general UI chrome: page backgrounds, card backgrounds, borders, primary text. Use hue scales only when conveying semantic meaning:

```tsx
// Neutral card
<div className="rounded-lg border border-sand-6 bg-sand-2 p-4">
  <p className="text-sand-12">Title</p>
  <p className="text-sand-11">Description</p>
</div>

// Error state
<div className="rounded-lg border border-red-6 bg-red-3 p-4">
  <p className="text-red-11">Something went wrong</p>
</div>

// Success badge
<span className="rounded bg-green-3 px-2 py-0.5 text-green-11">Approved</span>
```

## Contrast guarantees

Per the [Radix spec](https://www.radix-ui.com/colors/docs/palette-composition/understanding-the-scale), steps 11 and 12 — which are designed for text — are guaranteed to reach Lc 60 and Lc 90 APCA contrast respectively on top of a **step 2** background from the same scale. So both `text-sand-11` and `text-sand-12` are readable on `bg-sand-2`. The guarantee is documented against step 2 only; step 1 is the more extreme background (lighter in light mode, darker in dark mode), so text steps stay at least as readable there in practice, but Radix does not state it as a guarantee.

## Dark mode

**Never apply dark-mode color overrides in components.** The v2 theme imports `@radix-ui/colors` CSS files which handle light/dark switching automatically. Dark mode activates when a `.dark` class is present on `<html>`:

```ts
document.documentElement.classList.toggle("dark", isDark);
```

The same Tailwind classes (`bg-sand-1`, `text-red-11`, etc.) resolve to the correct dark values automatically because the `@theme inline` mappings reference the Radix variables (`var(--sand-1)`, etc.) which switch based on the `.dark` class. P3 wide-gamut colors are included for both light and dark modes on supported displays.

This is independent of v1's dark mode which uses `@variant dark` / `prefers-color-scheme`.

## Isolation from v1

v2 is a standalone theme isolated at the build level, not via a runtime DOM scope. An app opts into v2 by importing the v2 theme instead of the v1 `theme.css`:

```css
/* app index.css — v2 build */
@import "tailwindcss";
@import "@probo/ui/src/v2/theme.css";
```

The v2 theme wipes Tailwind's default palette (`--color-*: initial`), keeping only `transparent`, `black`, `white`, and the Radix scales below. Within a v2 build these color utilities are global — there is no `[data-theme="v2"]` ancestor requirement. A given build is either v1 or v2; the two do not coexist on the same page.

## Do / don't

### Use the numbered scale

```tsx
// Good — numbered scale step
<div className="border border-sand-7 bg-sand-3">...</div>

// Bad — hardcoded hex
<div className="border border-[#cfceca] bg-[#f1f0ef]">...</div>

// Bad — v1 semantic color names in a v2 component
<div className="border border-border-low bg-subtle">...</div>
```

### Respect step ranges

```tsx
// Good — step 3 for element background, step 11 for text
<button className="bg-sand-3 text-sand-12 hover:bg-sand-4">Save</button>

// Bad — step 11 is a text step, not a background step
<button className="bg-sand-11 text-white">Save</button>
```

### Do not mix v1 and v2 colors

```tsx
// Bad — mixing v1 (txt-primary) and v2 (sand-3) in one component
<div className="bg-sand-3 text-txt-primary">...</div>

// Good — all v2
<div className="bg-sand-3 text-sand-12">...</div>
```

### Let the theme handle dark mode

```tsx
// Bad — manual dark: overrides for v2 colors
<div className="bg-sand-1 dark:bg-sand-12">...</div>

// Good — just use the scale; dark values come from the theme scope
<div className="bg-sand-1">...</div>
```

### Solid backgrounds (steps 9–10)

Steps 9 and 10 are designed for prominent, solid-color backgrounds (primary buttons, badges, banners). Most step 9 colors are designed for white foreground text. Exceptions: **sky**, **amber** are designed for dark foreground text on steps 9–10.

```tsx
// Good — green solid button with white text
<button className="bg-green-9 text-white hover:bg-green-10">Approve</button>

// Good — amber badge with dark text (amber 9-10 are light/bright)
<span className="bg-amber-9 text-amber-12">Warning</span>
```

# Typography (`text-1` … `text-9`)

The type scale mirrors the color scale: numbered steps, not t-shirt sizes. Each `text-<n>` utility carries its paired font-size, line-height, and letter-spacing.

Theme file: [`packages/ui/src/v2/theme/typography.css`](../../packages/ui/src/v2/theme/typography.css)

| Step | Size | Typical use |
|------|------|-------------|
| 1 | 12px | Fine print, captions, metadata |
| 2 | 14px | Secondary / dense body, table cells |
| 3 | 16px | Body default |
| 4 | 18px | Lead paragraph, small headings |
| 5 | 20px | Section heading |
| 6 | 24px | Page heading |
| 7 | 28px | Large heading |
| 8 | 35px | Display |
| 9 | 60px | Hero |

Font family is **Inter Variable** (`font-sans`); mono is a system stack (`font-mono`). Weights: `font-light` (300), `font-normal` (400), `font-medium` (500), `font-bold` (700).

```tsx
// Good — numbered type step + weight + color step
<h1 className="text-6 font-medium text-sand-12">Measures</h1>
<p className="text-3 text-sand-11">Description</p>

// Bad — Tailwind default size (wiped in v2) or arbitrary value
<h1 className="text-2xl">Measures</h1>
<p className="text-[15px]">Description</p>
```

> Prefer the kit's `Text` / `Heading` / `Code` components over raw elements with these classes — they encode the step choice once. See [Typography: components over raw text elements](ui.md#typography-components-over-raw-text-elements).

# Radius (`rounded-1` … `rounded-6`)

Numbered radius scale (Radix "Medium" set). The static `rounded-none` / `rounded-full` utilities still work; the numeric ramp replaces Tailwind's `rounded-sm/md/lg`.

Theme file: [`packages/ui/src/v2/theme/radius.css`](../../packages/ui/src/v2/theme/radius.css)

| Step | Value | Typical use |
|------|-------|-------------|
| 1 | 3px | Subtle rounding (chips, small inputs) |
| 2 | 4px | Inputs, small buttons |
| 3 | 6px | Buttons, list items |
| 4 | 8px | Cards, dialogs |
| 5 | 12px | Large surfaces |
| 6 | 16px | Hero panels, modals |

```tsx
// Good — numbered radius
<div className="rounded-4 bg-sand-2">…</div>

// Bad — Tailwind default radius (wiped) or arbitrary value
<div className="rounded-lg">…</div>
<div className="rounded-[10px]">…</div>
```

# Shadows (`shadow-1` … `shadow-6`, `inset-shadow-1` … `inset-shadow-3`)

Drop-shadow elevation ramp, sand-tinted so it adapts to dark mode automatically (built from alpha tokens that flip light↔dark). Inset shadows live in the separate `inset-shadow-*` slot.

Theme file: [`packages/ui/src/v2/theme/shadows.css`](../../packages/ui/src/v2/theme/shadows.css)

| Step | Typical use |
|------|-------------|
| 1 | Hairline lift (resting cards) |
| 2 | Raised cards, inputs |
| 3 | Dropdowns, popovers |
| 4 | Dialogs |
| 5 | Large overlays |
| 6 | Highest elevation (modals over modals) |

```tsx
// Good — numbered elevation; dark mode is automatic
<div className="rounded-4 bg-sand-2 shadow-2">…</div>

// Bad — Tailwind default shadow (wiped) or a manual dark: override
<div className="shadow-md dark:shadow-none">…</div>
```

# Z-index (`z-1` … `z-6`)

Stacking scale by **UI layer role**, not arbitrary elevation. Prefer the step that matches the element type; never invent ad-hoc values (`z-10`, `z-[999]`) in a v2 build.

Theme file: [`packages/ui/src/v2/theme/z-index.css`](../../packages/ui/src/v2/theme/z-index.css)

| Step | Value | Role |
|------|-------|------|
| 1 | 1 | Local stacking inside a component (media over a decorative backdrop) |
| 2 | 10 | Sticky / fixed page chrome (top bars, sticky toolbars) |
| 3 | 30 | Floating menus (select, dropdown, tooltip, popover) |
| 4 | 40 | Overlay backdrops (dimmers under modals / drawers) |
| 5 | 50 | Modals and drawers |
| 6 | 60 | Toasts / global notifications (always on top) |

Put the token on the **portaled root** that participates in the document stacking context (e.g. a menu `Positioner`), not only an inner popup. A local `z-1` in the page will paint above a portaled popup that has no z-index of its own.

```tsx
// Good — local media above its own backdrop; menu sits in the popover layer
<div className="relative z-1">…logo…</div>
<Menu.Positioner className="z-3">…</Menu.Positioner>

// Bad — Tailwind default / arbitrary z-index (wiped or discouraged in v2)
<div className="z-10">…</div>
<div className="z-[999]">…</div>
```

# Spacing (Tailwind native)

Spacing is **not** tokenized — use Tailwind's native spacing scale (`p-4`, `gap-2`, `mt-6`, `size-8`). Do not invent a numbered spacing scale or use arbitrary pixel values where a native step fits.

```tsx
// Good — native spacing scale
<div className="flex flex-col gap-3 p-4">…</div>

// Bad — arbitrary spacing where a native step exists
<div className="p-[15px] gap-[7px]">…</div>
```