---
version: alpha
name: CodeSandbox
description: Dark design system extracted from codesandbox.io (DOM-true values, Emblematic extractor 0.2.0, 2026-11-12).
colors:
  background: "#0E0E0E"
  surface: "#161616"
  on-surface: "#F0F0F0"
  on-surface-variant: "#A3A3A3"
  primary: "#EAFF96"
  outline: "#252525"
  lime600: "#E3FF73"
  lime800: "#D6FB41"
  black600: "#1D1D1D"
  lime300: "#F5FFCB"
  yellow100: "#FFFFFF"
  foreground700: "#858585"
  purple500: "#B0A0FF"
  on-primary: "#343434"
typography:
  display-lg:
    fontFamily: Helvetica
    fontSize: 96px
    fontWeight: 500
    lineHeight: 1
    letterSpacing: -0.05em
  headline-md:
    fontFamily: Inter
    fontSize: 24px
    fontWeight: 400
  title-md:
    fontFamily: Inter
    fontSize: 24px
    fontWeight: 500
    lineHeight: 1.4
    letterSpacing: -0.025em
  body-md:
    fontFamily: Inter
    fontSize: 18px
    fontWeight: 400
    lineHeight: 1.4
    letterSpacing: -0.025em
  body-sm:
    fontFamily: Inter
    fontSize: 16px
    fontWeight: 400
  label-md:
    fontFamily: Inter
    fontSize: 12px
    fontWeight: 400
rounded:
  sm: 4px
  md: 6px
  lg: 10px
  full: 9999px
spacing:
  xxs: 4px
  xs: 8px
  sm: 16px
  md: 24px
  lg: 32px
  xl: 48px
  2xl: 80px
  3xl: 120px
  base: 8px
  container: 1200px
components:
  button-primary:
    backgroundColor: "{colors.primary}"
    textColor: "#343434"
    rounded: "{rounded.md}"
    padding: 13px
    height: 42px
    typography: "{typography.label-md}"
  button-secondary:
    backgroundColor: "{colors.black600}"
    textColor: "{colors.lime600}"
    rounded: "{rounded.sm}"
    padding: 8px
    height: 28px
    typography: "{typography.label-md}"
  card:
    backgroundColor: "{colors.lime800}"
    rounded: "{rounded.lg}"
    padding: 48px
---

# CodeSandbox

> Extracted from [https://codesandbox.io/](https://codesandbox.io/) on 2026-11-12 by Emblematic. Every value below was read from the rendered DOM (computed styles, `document.fonts`, and the fonts Chrome actually used to paint text), not estimated from pixels. When the YAML front matter and this prose disagree, the YAML wins. Copy values from this file exactly; don't transcribe them from memory. Don't copy logos, imagery, illustrations or marketing copy.

## Overview

CodeSandbox uses a dark canvas (#0E0E0E) with a palette led by #EAFF96. Type is set in **Helvetica** (display), **Inter**, with 18px body text. Layout: 1200px container, top-static+transparent navigation, 9 sections. Built with next.js, cloudflare.

## Colors

Area-weighted from painted backgrounds, text and borders on the 1440px light capture. Roles are inferred from usage (largest background, most text, interactive fills). Every hex is an exact computed value; a role marked *unverified* is a best guess that has not passed review, so its canonical token (e.g. `primary`) is left out of the front matter.

| Token | Hex | OKLCH | Role | Share of paint | CSS variable |
|---|---|---|---|---|---|
| `background` | `#0E0E0E` | 0.164 0 0 | bg | 42.8% | `--colors-background` |
| `surface` | `#161616` | 0.2 0 0 | surface | 18.5% | `--colors-black700` |
| `on-surface` | `#F0F0F0` | 0.955 0 0 | text | 5.7% | `--colors-text` |
| `on-surface-variant` | `#A3A3A3` | 0.715 0 0 | muted | 1.3% | `--colors-foreground600` |
| `primary` | `#EAFF96` | 0.962 0.132 118.2 | accent | 0.25% | `--colors-lime500` |
| `outline` | `#252525` | 0.264 0 0 | border | 0.07% | `--colors-black500` |
| `lime600` | `#E3FF73` | 0.952 0.168 119.1 | other | 14.4% | `--colors-lime600` |
| `lime800` | `#D6FB41` | 0.93 0.203 120.6 | other | 11.8% | `--colors-lime800` |
| `black600` | `#1D1D1D` | 0.231 0 0 | other | 2.8% | `--colors-black600` |
| `lime300` | `#F5FFCB` | 0.98 0.068 116.5 | other | 0.91% | `--colors-lime300` |
| `yellow100` | `#FFFFFF` | 1 0 0 | other | 0.75% | `--colors-yellow100` |
| `foreground700` | `#858585` | 0.617 0 0 | other | 0.33% | `--colors-foreground700` |
| `purple500` | `#B0A0FF` | 0.757 0.135 290.5 | other | 0.23% | `--colors-purple500` |

Sparse chromatic highlights (not accents): `#E3FF73` (`--colors-lime600`).

Contrast: text on background 16.94:1, muted text 7.65:1, accent 17.69:1.

The site does not change under `prefers-color-scheme: dark`.

## Typography

| Family | Role | Weights | Share of text | Source |
|---|---|---|---|---|
| **Helvetica** (CSS: `TWK Everett`) | display | 500 | 52.2% | system (stack `"TWK Everett", Inter, "Hevetica Neue", Helvetica, apple-syst`, resolved on macos) |
| **Inter** (CSS: `__Inter_f367f3`) | body | 400, 500 | 46.4% | webfont |
| **Material Symbols Outlined** | other | 200 | 1.4% | webfont |

Scale (px): 12, 14, 16, 18, 20, 22.5, 24, 28, 32, 48, 56, 88, 96, 120. Effective ratio ≈ 1.209 (close to a minor third). Body 18px at line-height 1.4; display 96px with tracking -0.05em. Headings are sentence case. On a 390px viewport the body is 16px and display 48px.

## Layout

Spacing follows a 8px base unit; the most used steps are 4, 8, 16, 24, 32, 48, 80, 120px. Sections open with about 80px of space before their first line of text. Content sits in a 1200px container. Text density 0.155 (text area / page area).

Section order (desktop). Kinds below the review threshold are shown as *section*:

1. **nav** (48px, bg #0E0E0E)
2. **section** — “CodeSandbox is now part of We have joined forces to launch and bring code interp” (48px, bg #DCFF50)
3. **hero** — “e l a c s r o f t l i u b s e x o b d n a S” (661px, bg #161616)
4. **section** (144px, bg #FFFFFF)
5. **section** — “Customizable hibernation” (1130px, bg #0E0E0E)
6. **section** — “Built for AI agents and more” (845px, bg #E3FF73)
7. **logos** — “Start with your favorite stack.” (1541px, bg #0E0E0E)
8. **section** — “Join the future of building” (769px, bg #0E0E0E)
9. **footer** (392px, bg #161616)

## Shapes

Dominant corner radius 10px; radii in use: 4px, 6px, 10px, pill. Borders: heavy (4px).

## Components

- **button-primary**: backgroundColor `#EAFF96`, textColor `#343434`, rounded `6px`, padding `13px 16px`, height `42px`, fontFamily `Inter`, fontSize `16px`, fontWeight `500` (e.g. “Start for free”)
- **button-secondary**: backgroundColor `#1D1D1D`, textColor `#E3FF73`, rounded `4px`, padding `8px 12px`, height `28px`, fontFamily `Inter`, fontSize `12px`, fontWeight `500` (e.g. “Learn more”)
- **card**: rounded `10px`, padding `48px`, backgroundColor `#D6FB41`

## Do's and Don'ts

- Do reserve `#EAFF96` for primary actions and highlights; it covers only 0.25% of the painted page.
- Do set body copy in Inter at 18px / 1.4.
- Do use Helvetica only for display sizes, not for body text.
- Do tighten large headlines (-0.05em at 96px).
- Don't introduce font weights beyond 200, 400, 500.
- Don't add drop shadows; depth comes from tone and borders.
- Do keep corners at 10px for most controls, and use the larger radii only for cards and media.
- Do snap spacing to multiples of 8px.
- Don't copy this site's logos, illustrations, photography or copy; use the system, not the brand assets.

## Provenance

Spec v2, extractor 0.2.0. Render quality: **ok**. Vision pass: not run. Fields below confidence 0.7 are hedged or left out above: `color.accent_strategy`, `layout.columns`, `layout.hero`, `layout.section_count`, `sections[].kind`, `space.section_padding_px`. Full per-field provenance is in `spec.json`.