Biome — decoded design system

biomejs.dev · light · modern · custom · deep decode — measured live

Biome's design system, decoded live by Mozaika: measured color roles, type scale, buttons with real hover/focus states, motion and the brand's own tokens.

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This is a static, crawlable rendering for search & AI engines. The interactive version — filters, live decode console, copy & export — is at https://mozaika.design/decode/biomejs.dev.

Decoded design system

Biome's decoded design system: background #FFFFFF, text #353841, accent #0065DA, link #0065DA, primary #0065DA; type scale h1 64px / h2 40px / body 16px; 4px spacing base; 3px base radius. The single interactive/action color is #0065DA — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Using these colors

• Action color #0065DA — the single interactive color; only on things you click or must notice, never large fills.
• primary, accent, link, button_bg are all #0065DA — one role, not several (the action color).
• accent #0065DA — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
• secondary #ABB2BF — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.

Typography

• Heading: Arial
• Body: Arial
• Mono: ui-monospace
• h1: 64px
• h2: 40px
• body: 16px

Spacing

• base unit: 4px
• scale: 4px, 6px, 8px, 10px, 12px, 13px, 15px, 16px, 19px, 24px

Radii

• base: 3px
• button: 4.8px

Shadows (elevation)

• subtle: rgba(0, 0, 0, 0.06) 0px 1px 1px 0px, rgba(0, 0, 0, 0.06) 0px 2px 1px 0px

Motion

Micro-interactions run at 200ms (dominant) with cubic-bezier(0.25, 0.46, 0.45, 0.94).

• durations: 200ms · 500ms · 100ms
• easings: cubic-bezier(0.25, 0.46, 0.45, 0.94) · ease
• animated properties: opacity, background, border-color, width

Native design tokens

…and 110 more measured on the page.

Button states (measured)

• primary focus: outline 1px auto rgb(16, 16, 16)

Layout (measured)

• container max-width: 1080px
• nav: 64px fixed
• common grid: 2 columns

Overlay recipe (measured)

dialog panel: #ECEEF2 · radius 8px

Themes

dark counterpart: background #17181C, text #C0C2C7.

Responsive (measured)

• breakpoints: 480px · 600px · 768px · 800px · 960px · 970px
• mobile (390px): hero 29px · nav hamburger

Install it

Drop this measured system into any shadcn/Tailwind project in one command:

npx shadcn add mozaika.design/r/decode/biomejs.dev

registry item · or query it over MCP: get_design_system("Biome")

Export: DESIGN.md

# Biome — Design System

> light, modern, medium, custom — deep decode (measured live)

## Colors

| Role | Value |
|------|-------|
| bg | `#FFFFFF` |
| surface | `#F2F3F3` |
| border | `#E0E1E2` |
| text | `#353841` |
| text_muted | `#818389` |
| primary | `#0065DA` |
| accent | `#0065DA` |
| link | `#0065DA` |
| secondary | `#ABB2BF` |
| button_bg | `#0065DA` |
| button_text | `#FFFFFF` |

**Using these colors**

- **Action color** `#0065DA` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `primary`, `accent`, `link`, `button_bg` are all `#0065DA` — one role, not several (your action color).
- **accent** `#0065DA` — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
- **secondary** `#ABB2BF` — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.
- **Page coverage** (full-page screenshot pixels): `#FFFFFF` 66.6% · `#D9E7F9` 24.3% · `#487AB7` 9.1%

## Typography

- Heading: **Arial**
- Body: **Arial**
- Mono: **ui-monospace** _(measured)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 64px / 600 · lh 77px |
| h2 | 40px / 400 · lh 70px |
| h3 | 24px / 600 · lh 29px |
| body | 16px / 400 · lh 28px |
| small | 14px / 400 · lh 25px |

- Weight ladder: 400 · 500 · 600 · 700 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Arial — system font, no web load needed.

## Spacing
- base unit: 4px (inferred from the measured scale)
- measured scale: 4px, 6px, 8px, 10px, 12px, 13px, 15px, 16px, 19px, 24px — snap all gaps/padding to these

## Radius
- base: 3px
- button: 4.8px
- card: 800px
- pill: 9999px
- sharp: 3px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `#0065DA` / `#FFFFFF` | 1px solid rgb(0, 101, 218) | 4.8px | 15px 20px 15px 20px | 400 16px | none |
| secondary | `#FFFFFF` / `#353841` | 1px solid rgb(192, 194, 199) | 8px | 1px 8px 1px 12px | 400 14px | none |

**States (measured, not guessed)**

- primary focus: outline `1px auto rgb(16, 16, 16)`
- secondary hover: border `1px solid rgb(53, 56, 65)` · color `#17181C`

## Shadows (elevation)
- subtle: `rgba(0, 0, 0, 0.06) 0px 1px 1px 0px, rgba(0, 0, 0, 0.06) 0px 2px 1px 0px`

## Motion
- durations: 200ms (dominant) · 500ms · 100ms
- easings: `cubic-bezier(0.25, 0.46, 0.45, 0.94)` (dominant) · `ease`
- animated properties: opacity, background, border-color, width

Micro-interactions use the dominant duration + easing; nothing on the page animates slower than the longest duration above — don't invent springier motion.

## Their own tokens (verbatim from :root)

| Token | Value |
|-------|-------|
| `--sl-color-accent-low` | `#c2d9fa` |
| `--sl-color-accent` | `#0065da` |
| `--sl-color-accent-high` | `#093066` |
| `--sl-color-white` | `#17181c` |
| `--sl-color-gray-1` | `#24272f` |
| `--sl-color-gray-2` | `#353841` |
| `--sl-color-gray-3` | `#545861` |
| `--sl-color-gray-4` | `#888b96` |
| `--sl-color-gray-5` | `#c0c2c7` |
| `--sl-color-gray-6` | `#eceef2` |
| `--sl-color-black` | `#ffffff` |
| `--sl-community-link` | `#ffffff` |

_…and 108 more measured on the page._

Prefer these names when extending their system — it's the brand's actual vocabulary.

## Layout (measured)
- container max 1080px · common grid: 2-col
- nav: 64px fixed · border-bottom 1px solid rgb(236, 238, 242) · bg #F5F6F8

## Motion choreography (measured)
- overlay dialog (auto-opened): panel #ECEEF2 · r 8px · border 1px solid rgb(192, 194, 199) · shadow 

Rebuild the timeline, not just the durations — order, delays and staggers above are the choreography.

## Components (measured)
- card ×6: pad 40px 40px 40px 40px · r 0px · border 1px solid rgb(192, 194, 199) · bg #FFFFFF
  - hover: border `1px solid rgb(20, 57, 108)` · font-weight `400` · font-size `19.6125px` · letter-spacing `normal`
- link: #FFFFFF · underline

## Themes (both measured)
- dark counterpart: bg `#17181C` · text `#C0C2C7`
- tokens that flip between modes:
  - `--sl-color-accent-low`: `#c2d9fa` → `#131e4f`
  - `--sl-color-accent`: `#0065da` → `#3447ff`
  - `--sl-color-accent-high`: `#093066` → `#60a5fa`
  - `--sl-color-white`: `#17181c` → `#ffffff`
  - `--sl-color-gray-1`: `#24272f` → `#eceef2`
  - `--sl-color-gray-2`: `#353841` → `#c0c2c7`
  - `--sl-color-gray-3`: `#545861` → `#888b96`
  - `--sl-color-gray-4`: `#888b96` → `#545861`

## Responsive (measured)
- breakpoints: 480px · 600px · 768px · 800px · 960px · 970px
- mobile (390px): hero 29px · body 16px · nav: hamburger

## How to apply
Paste the Tailwind `@theme` (or CSS variables) as your base, then build each
section to its spec — verify every color, radius, and font against these tokens.
Hover/focus states, shadows and motion timings above are measured from the live page — match them exactly, don't re-guess them.

← All decoded design systems

An automated reading of Biome's publicly-visible CSS (colors, fonts, spacing, motion) — not affiliated with biomejs.dev. No screenshots stored. Removal requests: hello@mozaika.design.