Observable — decoded design system

observablehq.com · light · modern · tailwind · deep decode — measured live

Observable'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/observablehq.com.

Decoded design system

Observable's decoded design system: background #F5F5F5, text #000000, accent #1C1C1C, link #FFFFFF, primary #1690F6; type scale h1 56px / h2 40px / body 20px; 8px spacing base; 2px base radius. The single interactive/action color is #FFFFFF — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Using these colors

• Action color #FFFFFF — the single interactive color; only on things you click or must notice, never large fills.
• link, button_bg are all #FFFFFF — one role, not several (the action color).
• accent #1C1C1C — accent for emphasis — keep it rare on the page.
• primary #1690F6 — a brand color — but the call-to-action uses #FFFFFF, not this.
• secondary #FFFF00 — 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: Spline Sans Mono
• Body: Inter
• Mono: __Spline_Sans_Mono_1999fd
• h1: 56px
• h2: 40px
• body: 20px

Spacing

• base unit: 8px
• scale: 2px, 8px, 10px, 15px, 16px, 21px, 24px, 32px, 34px, 48px

Radii

• base: 2px
• button: 0px

Shadows (elevation)

• subtle: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.1) 0px 10px 15px -3px, rgba(0, 0, 0, 0.1) 0px 4px 6px -4px
• card: rgba(0, 0, 0, 0.12) 0px 4px 15px 0px

Motion

Micro-interactions run at 200ms (dominant) with ease-in-out.

• durations: 200ms · 100ms · 150ms
• easings: ease-in-out · cubic-bezier(0.4, 0, 0.2, 1)
• animated properties: opacity, border-color, height, background-color

Native design tokens

…and 110 more measured on the page.

Button states (measured)

• primary hover: background #EEEEEE
• primary focus: outline 1px auto rgb(16, 16, 16)

Layout (measured)

• nav: 64px sticky
• common grid: 12 columns

Motion choreography (measured)

Load order: div.jsx-3b5ab7e5d596c6f5 → div.jsx-1468fe3ac7fdbbd4×17 → div.jsx-33d4ea7186cd0717×10

Scroll reveal: 3 elements rest at a pre-reveal state.

Responsive (measured)

• breakpoints: 450px · 480px · 640px · 768px · 800px · 960px
• mobile (390px): hero 28px · nav hamburger

Install it

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

npx shadcn add mozaika.design/r/decode/observablehq.com

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

Export: DESIGN.md

# Observable — Design System

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

## Colors

| Role | Value |
|------|-------|
| bg | `#F5F5F5` |
| surface | `#E6E6E6` |
| border | `#D0D0D0` |
| text | `#000000` |
| text_muted | `#5D5D5D` |
| primary | `#1690F6` |
| accent | `#1C1C1C` |
| link | `#FFFFFF` |
| secondary | `#FFFF00` |
| button_bg | `#FFFFFF` |
| button_text | `#1C1C1C` |

**Using these colors**

- **Action color** `#FFFFFF` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `link`, `button_bg` are all `#FFFFFF` — one role, not several (your action color).
- **accent** `#1C1C1C` — accent for emphasis — keep it rare on the page.
- **primary** `#1690F6` — a brand color — but the call-to-action uses #FFFFFF, not this.
- **secondary** `#FFFF00` — 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` 46.9% · `#1C1C1C` 35.3% · `#609A96` 10.5% · `#CAE4E6` 7.2%

## Typography

- Heading: **Spline Sans Mono** _(free fallback: JetBrains Mono)_
- Body: **Inter**
- Mono: **__Spline_Sans_Mono_1999fd** _(measured)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 56px / 500 · lh 64px |
| h2 | 40px / 500 · lh 48px |
| body | 20px / 400 · lh 28px |
| small | 18px / 500 · lh 28px |
| eyebrow | 16px / 700 · tracking 1.6px |

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

> **Fonts —** Spline Sans Mono may be proprietary — safe free fallback: JetBrains Mono (Google Fonts). Inter — free, on Google.

## Spacing
- base unit: 8px (inferred from the measured scale)
- measured scale: 2px, 8px, 10px, 15px, 16px, 21px, 24px, 32px, 34px, 48px — snap all gaps/padding to these

## Radius
- base: 2px
- button: 0px
- card: 4px
- sharp: 2px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `#FFFFFF` / `#1C1C1C` | none | 0px | 8px 16px 8px 16px | 600 16px | none |
| secondary | `rgba(0, 0, 0, 0)` / `#FFFFFF` | 2px solid rgb(255, 255, 255) | 0px | 20.5px 16px 20.5px 16px | 700 16px | none |

**States (measured, not guessed)**

- primary hover: background `#EEEEEE`
- primary focus: outline `1px auto rgb(16, 16, 16)`
- secondary hover: background `rgba(255, 255, 255, 0.05)`

## Shadows (elevation)
- subtle: `rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.1) 0px 10px 15px -3px, rgba(0, 0, 0, 0.1) 0px 4px 6px -4px`
- card: `rgba(0, 0, 0, 0.12) 0px 4px 15px 0px`

## Motion
- durations: 200ms (dominant) · 100ms · 150ms
- easings: `ease-in-out` (dominant) · `cubic-bezier(0.4, 0, 0.2, 1)`
- animated properties: opacity, border-color, height, background-color

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 |
|-------|-------|
| `--black` | `#000` |
| `--white` | `#fff` |
| `--near-black` | `#1c1c1c` |
| `--dark-gray` | `#454545` |
| `--mid-gray` | `#6e6e6e` |
| `--moon-gray` | `#c4c4c4` |
| `--light-gray` | `#e2e2e2` |
| `--near-white` | `#f5f5f5` |
| `--gray` | `#929292` |
| `--silver` | `#e8e8e8` |
| `--light-silver` | `#efefef` |
| `--black-90` | `#16191d` |

_…and 108 more measured on the page._

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

## Layout (measured)
- common grid: 12-col
- nav: 64px sticky

| Section (y) | Height | Cols | Gap | Pad y | Split |
|---|---|---|---|---|---|
| 931 | 693 | 12 | 32 | 0/0 | — |

## Motion choreography (measured)
Load order: `div.jsx-3b5ab7e5d596c6f5` @0ms → `div.jsx-1468fe3ac7fdbbd4`×17 @537ms → `div.jsx-33d4ea7186cd0717`×10 @1068ms
- scroll reveal: 3 elements rest at a pre-reveal state (3 revealed during the drive).

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

## Responsive (measured)
- breakpoints: 450px · 480px · 640px · 768px · 800px · 960px
- mobile (390px): hero 28px · body 14px · 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 Observable's publicly-visible CSS (colors, fonts, spacing, motion) — not affiliated with observablehq.com. No screenshots stored. Removal requests: hello@mozaika.design.