---
version: alpha
name: Buildwithfern
description: Light design system extracted from buildwithfern.com (DOM-true values, Emblematic extractor 0.2.0, 2026-11-12).
colors:
  background: "#F7F7F7"
  on-surface: "#202020"
  on-surface-variant: "#737373"
  surface: "#FFFFFF"
  outline: "#E4E4E4"
  primary: "#008700"
  color-7: "#FF6C3733"
  color-8: "#FFFFFFB3"
  color-9: "#0000002E"
  color-10: "#F7F7F7CC"
  comet: "#009D00"
  color-12: "#FCFCFD4D"
  black: "#000000"
  slate-11: "#60646C"
  color-15: "#FFFFFFE6"
  neutral-900: "#171717"
  background-dark: "#0A0A0A"
  on-surface-dark: "#FFFFFF"
  on-surface-variant-dark: "#A1A1A1"
  surface-dark: "#171717"
  primary-dark: "#9CDD8D"
  outline-dark: "#252525"
typography:
  display-lg:
    fontFamily: GT Planar
    fontSize: 48px
    fontWeight: 400
    lineHeight: 1.15
    letterSpacing: -0.04em
  headline-md:
    fontFamily: GT Planar
    fontSize: 36px
    fontWeight: 400
    letterSpacing: -0.04em
  title-md:
    fontFamily: GT Planar
    fontSize: 24px
    fontWeight: 400
    letterSpacing: -0.02em
  body-md:
    fontFamily: GT Planar
    fontSize: 16px
    fontWeight: 300
    lineHeight: 1.7
  body-sm:
    fontFamily: Inter
    fontSize: 13px
    fontWeight: 400
    lineHeight: 1.5
  label-md:
    fontFamily: GT Planar
    fontSize: 14px
    fontWeight: 300
    lineHeight: 1.4
  mono-md:
    fontFamily: Berkeley Mono
    fontSize: 3.25px
    fontWeight: 400
    lineHeight: 1.1
rounded:
  xs: 4px
  sm: 5px
  md: 6px
  lg: 8px
  xl: 10px
  2xl: 14px
  3xl: 18px
  4xl: 24px
  full: 9999px
spacing:
  xxs: 2px
  xs: 4px
  sm: 6px
  md: 8px
  lg: 10px
  xl: 12px
  2xl: 14px
  3xl: 16px
  4xl: 20px
  5xl: 24px
  6xl: 32px
  7xl: 40px
  8xl: 48px
  container: 1376px
components:
  button-primary:
    backgroundColor: "{colors.neutral-900}"
    textColor: "#FAFAFA"
    rounded: "{rounded.xl}"
    padding: 0px
    height: 32px
    typography: "{typography.label-md}"
  button-secondary:
    backgroundColor: "#4D7E5C"
    textColor: "{colors.surface}"
    rounded: "{rounded.lg}"
    padding: 6px
    height: 30px
    typography: "{typography.label-md}"
  card:
    backgroundColor: "{colors.color-12}"
    rounded: 32px
    padding: 8px
  input:
    rounded: "{rounded.xl}"
    padding: 4px
    height: 32px
---

# Buildwithfern

> Extracted from [https://buildwithfern.com/](https://buildwithfern.com/) 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

Buildwithfern uses a light canvas (#F7F7F7) with a palette led by #008700. Type is set in **GT Planar** (display + body), **Berkeley Mono** (mono), with 16px body text. Layout: 1376px container, none-detected navigation, 15 sections. Built with next.js, radix-ui, shadcn/ui, posthog, google-tag-manager, vercel, 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` | `#F7F7F7` | 0.977 0 172.2 | bg | 82.6% | `--background` |
| `on-surface` | `#202020` | 0.244 0 0 | text | 3.9% | `--foreground` |
| `on-surface-variant` | `#737373` | 0.556 0 129.6 | muted | 3.0% | `--muted-foreground` |
| `surface` | `#FFFFFF` | 1 0 113.7 | surface | 2.7% | `--card` |
| `outline` | `#E4E4E4` | 0.92 0 345.6 | border | 0.99% | `--border` |
| `primary` | `#008700` | 0.54 0.184 142.5 | accent | 0.24% | `--brand` |
| `color-7` | `#FF6C3733` (on bg `#F9DBD1`) | 0.706 0.191 39.2 | other | 0.95% | — |
| `color-8` | `#FFFFFFB3` (on bg `#FDFDFD`) | 1 0 0 | other | 0.72% | — |
| `color-9` | `#0000002E` (on bg `#CBCBCB`) | 0 0 0 | other | 0.82% | — |
| `color-10` | `#F7F7F7CC` (on bg `#F7F7F7`) | 0.977 0 113.2 | other | 0.71% | — |
| `comet` | `#009D00` | 0.604 0.206 142.5 | other | 0.71% | `--comet` |
| `color-12` | `#FCFCFD4D` (on bg `#F9F9F9`) | 0.991 0.001 288.5 | other | 0.54% | — |
| `black` | `#000000` | 0 0 0 | other | 0.31% | `--color-black` |
| `slate-11` | `#60646C` | 0.502 0.014 264.4 | other | 0.29% | `--slate-11` |
| `color-15` | `#FFFFFFE6` (on bg `#FEFEFE`) | 1 0 39 | other | 0.22% | — |
| `neutral-900` | `#171717` | 0.205 0 176.3 | other | 0.10% | `--color-neutral-900` |

Sparse chromatic highlights (not accents): `#009D00` (`--comet`), `#C5552D`, `#4963A4` (`--radix-blue-11`), `#007B00`.

Declared brand/accent tokens: `--brand-human` = `#0D74CE`, `--brand-elevenlabs` = `#D15A15` (declared, not painted on this page).

Contrast: text on background 15.25:1, muted text 4.43:1, accent 4.4:1.

Gradients in use: `linear-gradient(rgb(255, 255, 255), rgb(255, 255, 255)), linear-gradient(135deg, rgba(255, 255, 255, 0.7), rgba(0, 0, 0, 0.18))`; `radial-gradient(80% 70% at 50% 100%, rgba(255, 108, 55, 0.2) 0%, rgba(255, 108, 55, 0) 100%)`.

The site responds to `prefers-color-scheme: dark`; the `-dark` tokens hold the dark-mode roles.

## Typography

| Family | Role | Weights | Share of text | Source |
|---|---|---|---|---|
| **GT Planar** (CSS: `gtPlanar`) | display, body | 300, 400, 500 | 80.0% | webfont |
| **Berkeley Mono** (CSS: `berkeleyMono`) | mono | 100, 400, 500 | 8.5% | webfont |
| **Inter** | other | 400, 500, 600, 700 | 8.2% | webfont |
| **JetBrains Mono** | other | 400, 700 | 3.3% | webfont |

Declared in `@font-face` but not used to paint text on this page: Lato. Don't treat these as the page's fonts.

Scale (px): 3.5, 10, 11, 12, 12.5, 13, 14, 15, 16, 18, 20, 24, 32, 36, 48. Effective ratio ≈ 1.201 (close to a minor third). Body 16px at line-height 1.7; display 48px with tracking -0.04em. Headings are sentence case. On a 390px viewport the body is 14px and display 32px.

## Layout

Spacing has no reliable single base unit; the most used steps are 2, 4, 6, 8, 10, 12, 14, 16, 20, 24, 32, 40, 48px. Sections open with about 112px of space before their first line of text. Content sits in a 1376px container on a 6-column grid. Text density 0.09 (text area / page area).

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

1. **hero** — “Upgrade your developer and agent experience” (310px, bg #F7F7F7)
2. **section** — “Create Agent” (1038px, bg #F0F0F3)
3. **section** (430px, bg #F7F7F7)
4. **section** — “h t u r t f o e c r u o s e n o m o r f I L C d n a , s K D S , s c o D” (562px, bg #F7F7F7)
5. **section** — “CLI” (469px, bg #F7F7F7)
6. **section** — “a r e I A e h t r o f d e n g i s e D” (1451px, bg #F7F7F7)
7. **section** — “m r o f t a l p e s i r p r e t n e e h t o t e t a r g i M” (722px, bg #F7F7F7)
8. **section** — “t l u a f e d y b y d a e r - e s i r p r e t n E” (1063px, bg #F7F7F7)
9. **section** — “Native Postman support” (860px, bg #F7F7F7)
10. **section** — “s r e m o t s u c r u o m o r f t i r a e H” (327px, bg #F7F7F7)
11. **testimonials** (528px, bg #F9F9FB)
12. **section** — “m a e t n r e F e h t m o r f s e t o n d l e i F” (683px, bg #F7F7F7)
13. **logos** — “e c n e i r e p x e r e p o l e v e d r u o y e t a v e l E” (478px, bg #F7F7F7)
14. **footer** (556px, bg #F7F7F7)
15. **section** (576px, bg #F7F7F7)

## Elevation & Depth

Style: elevated. Most used shadows:

- `rgba(16, 18, 24, 0.04) 0px 1px 2px 0px, rgba(16, 18, 24, 0.18) 0px 18px 40px -12px`
- `rgba(0, 0, 0, 0.1) 0px 1px 3px 0px, rgba(0, 0, 0, 0.1) 0px 1px 2px -1px`
- `rgba(0, 0, 0, 0.08) 0px 1px 2px 0px`

## Shapes

Dominant corner radius 10px; radii in use: 4px, 5px, 6px, 8px, 10px, 14px, 18px, 24px, 32px, pill. Borders: hairline (1px).

## Components

- **button-primary**: backgroundColor `#171717`, textColor `#FAFAFA`, rounded `10px`, padding `0px 10px`, height `32px`, fontFamily `GT Planar`, fontSize `14px`, fontWeight `500` (e.g. “Book a demo”)
- **button-secondary**: backgroundColor `#4D7E5C`, textColor `#FFFFFF`, rounded `8px`, padding `6px 12px`, height `30px`, fontFamily `Inter`, fontSize `12px`, fontWeight `600` (e.g. “Try it”)
- **card**: rounded `32px`, padding `8px`, backgroundColor `#FCFCFD4D`, border `1px solid #D9D9E066`
- **input**: rounded `10px`, height `32px`, padding `4px 12px`, border `1px solid #E5E5E5`

## Do's and Don'ts

- Do reserve `#008700` for primary actions and highlights; it covers only 0.24% of the painted page.
- Do set body copy in GT Planar at 16px / 1.7.
- Do tighten large headlines (-0.04em at 48px).
- Don't introduce font weights beyond 100, 300, 400, 500, 600, 700.
- Do keep corners at 10px for most controls, and use the larger radii only for cards and media.
- 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.base`, `space.section_padding_px`. Full per-field provenance is in `spec.json`.