MozaikaDesign system

PostHog — Design System

light · modern · medium · tailwind · confidence 90% · deep decode

PostHog turns its whole site into a bit: a fake desktop OS on warm paper #EEEFE9 where every page opens as a draggable document window, so the marketing reads like files on a founder's computer. Open Runde headlines stay document-small (24px/800) while IBM Plex Sans carries 15px body — README typography, not billboard type. Hand-drawn hedgehogs do the brand work, amber #CD8407 buttons and the signal orange #F54E00 do the pointing, and the conversion moments are jokes played straight: a shrink-wrapped 'PostHog 3000' CD-ROM box, a fake cart toast, a pricing letter from the co-founder. It is the rare developer brand where humor is the design system — and the transparency reads as credibility.

Open in Mozaika →

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

Tokens

PostHog's decoded design system: background #E1D7C2, text #4D4F46, accent #CD8407, link #E3DFD1, primary #E1D7C2; type scale h1 16px / h2 16px / body 12px; 4px spacing base; 4px base radius. The single interactive/action color is #CD8407 — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

RoleValue
bg#E1D7C2
surface#D8CEBA
border#CAC2AF
text#4D4F46
text_muted#858275
primary#E1D7C2
accent#CD8407
link#E3DFD1
secondary#DDD6C5
button_bg#CD8407
button_text#23251D

Using these colors

Typography

Spacing

Radii

Shadows (elevation)

Motion

Micro-interactions run at 150ms (dominant) with cubic-bezier(0.4, 0, 0.2, 1).

Native design tokens

TokenValue
--viewport-padding25px

Button states (measured)

Layout (measured)

Motion choreography (measured)

Load order: svg.w-[189px]×2 → a.bg-button-shadow×2 → path.segment×3 → g.segment → li.ToastRoot → div.data-[state=active]:anim

Overlay recipe (measured)

dialog panel: #1E1F23 · radius 6px

Themes

dark counterpart: background #1D1F27, text #000000.

Responsive (measured)

Per-section tokens (28)

Export: DESIGN.md

# PostHog — Design System

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

PostHog turns its whole site into a bit: a fake desktop OS on warm paper #EEEFE9 where every page opens as a draggable document window, so the marketing reads like files on a founder's computer. Open Runde headlines stay document-small (24px/800) while IBM Plex Sans carries 15px body — README typography, not billboard type. Hand-drawn hedgehogs do the brand work, amber #CD8407 buttons and the signal orange #F54E00 do the pointing, and the conversion moments are jokes played straight: a shrink-wrapped 'PostHog 3000' CD-ROM box, a fake cart toast, a pricing letter from the co-founder. It is the rare developer brand where humor is the design system — and the transparency reads as credibility.

## Colors

| Role | Value |
|------|-------|
| bg | `#E1D7C2` |
| surface | `#D8CEBA` |
| border | `#CAC2AF` |
| text | `#4D4F46` |
| text_muted | `#858275` |
| primary | `#E1D7C2` |
| accent | `#CD8407` |
| link | `#E3DFD1` |
| secondary | `#DDD6C5` |
| button_bg | `#CD8407` |
| button_text | `#23251D` |

**Using these colors**

- **Action color** `#CD8407` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `primary` `#E1D7C2`, `secondary` `#DDD6C5` are visually the same color (Δ8) — treat as one role.
- `accent`, `button_bg` are all `#CD8407` — one role, not several (your action color).
- **accent** `#CD8407` — 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.
- **link** `#E3DFD1` — fails contrast on the background (~1.1:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference).
- **Page coverage** (full-page screenshot pixels): `#FDFDF8` 50.1% · `#D9D2C1` 40.5% · `#947958` 9.5%

## Typography

- Heading: **Open Runde** _(free fallback: Newsreader)_
- Body: **IBM Plex Sans**

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 36px / 800 · lh 40px · tracking -0.9px |
| h2 | 24px / 700 · lh 32px · tracking -0.6px |
| h3 | 21px / 700 · lh 30px · tracking -0.54px |
| body | 15px / 400 · lh 23px |
| small | 14px / 600 · lh 20px |

- Weight ladder: 400 · 500 · 600 · 700 · 800 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Open Runde may be proprietary — safe free fallback: Newsreader (Google Fonts). IBM Plex Sans — free, on Google.

## Spacing
- base unit: 4px (inferred from the measured scale)
- measured scale: 2px, 4px, 5px, 6px, 8px, 10px, 12px, 16px, 20px, 24px — snap all gaps/padding to these

## Radius
- base: 4px
- button: 6px
- card: 4px
- pill: 9999px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `#CD8407` / `#23251D` | 1px solid rgb(177, 120, 22) | 6px | 0px 0px 0px 0px | 400 16px | none |
| secondary | `rgba(0, 0, 0, 0)` / `#4D4F46` | none | — | 0px 0px 0px 0px | 400 16px | none |

**States (measured, not guessed)**

- primary focus: outline `1px auto rgb(16, 16, 16)`
- transition: `color 0.15s cubic-bezier(0.4, 0, 0.2, 1)`

## 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, 0.25) 0px 25px 50px -12px`
- card: `rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(14, 18, 22, 0.35) 0px 10px 38px -10px, rgba(14, 18, 22, 0.2) 0px 10px 20px -15px`

## Motion
- durations: 150ms (dominant) · 300ms · 3000ms
- easings: `cubic-bezier(0.4, 0, 0.2, 1)` (dominant) · `linear`
- animated properties: color, background-color, border-color, text-decoration-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 |
|-------|-------|
| `--viewport-padding` | `25px` |

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

## Layout (measured)
- container max 900px · common grid: 2-col
- nav: 0px

| Section (y) | Height | Cols | Gap | Pad y | Split |
|---|---|---|---|---|---|
| 162 | 714 | — | — | 0/0 | — |
| 3367 | 511 | 2 | 64 | 0/0 | — |

## Motion choreography (measured)
Load order: ``×2 @0ms → `a.bg-button-shadow`×2 @1ms → `path.segment`×3 @46ms → `g.segment` @469ms → `li.ToastRoot` @1493ms → `` @2729ms
- `?` — transform scale(1)→scale(1) — 2000ms · loops
- `a.bg-button-shadow` — transform scale(1)→scale(1) — 3000ms · loops
- overlay dialog (auto-opened): panel #1E1F23 · r 6px · border 1px solid rgb(62, 66, 79) · shadow rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(14, 18, 22, 0.35) 0px 10px 38px -10px, rgba(14, 18, 22, 0.2) 0px 10px 20px -15px

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

## Components (measured)
- link: #65675E · no underline — hover #4D4F46
- disabled: bg rgba(0, 0, 0, 0) · text #9EA096

## Themes (both measured)
- dark counterpart: bg `#1D1F27` · text `#000000`

## Responsive (measured)
- mobile (390px): hero 24px · body 16px · nav: inline

## 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.

---

> **Decoded with Mozaika** — measured live, not guessed. Full decoded design system + one-command install: mozaika.design/ds/posthog

Export: Tailwind v4 (@theme)

@theme {
  /* action color #CD8407 — the one interactive color; buttons/links/emphasis only, never large fills. */
  --color-bg: #E1D7C2;
  --color-surface: #D8CEBA;
  --color-border: #CAC2AF;
  --color-text: #4D4F46;
  --color-text-muted: #858275;
  --color-primary: #E1D7C2;  /* a neutral UI color (chips, tags, icon fills, chrome), not the action color (action = #CD8407). */
  --color-accent: #CD8407;  /* 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. */
  --color-link: #E3DFD1;  /* fails contrast on the background (~1.1:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference). */
  --color-secondary: #DDD6C5;  /* 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. */
  --color-button-bg: #CD8407;  /* primary-button fill — the main call-to-action color. */
  --color-button-text: #23251D;
  /* fonts: Open Runde may be proprietary — safe free fallback: Newsreader (Google Fonts). IBM Plex Sans — free, on Google. */
  --font-heading: "Open Runde", "Newsreader", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: "IBM Plex Sans", system-ui, -apple-system, 'Segoe UI', sans-serif;
  /* measured weights: 400, 500, 600, 700, 800 — use these, not 400/600 */
  --text-hero: 36px; --font-weight-hero: 800; --leading-hero: 40px; --tracking-hero: -0.9px;
  --text-h2: 24px; --font-weight-h2: 700; --leading-h2: 32px; --tracking-h2: -0.6px;
  --text-h3: 21px; --font-weight-h3: 700; --leading-h3: 30px; --tracking-h3: -0.54px;
  --text-body: 15px; --font-weight-body: 400; --leading-body: 23px;
  --text-small: 14px; --font-weight-small: 600; --leading-small: 20px;
  --radius-base: 4px;
  --radius-button: 6px;
  --radius-card: 4px;
  --radius-pill: 9999px;
  --shadow-card: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(14, 18, 22, 0.35) 0px 10px 38px -10px, rgba(14, 18, 22, 0.2) 0px 10px 20px -15px;
  --shadow-subtle: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.25) 0px 25px 50px -12px;
  --outline-focus: 1px auto rgb(16, 16, 16);  /* measured focus ring */
  --ease-brand: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-fast: 150ms;  /* use: duration-[var(--duration-fast)] */
  --duration-base: 300ms;
  --duration-slow: 3000ms;
  --spacing: 4px;  /* measured base — drives the p-*/gap-* scale. steps seen on the page: 2, 4, 5, 6, 8, 10, 12, 16, 20, 24px */
}

Export: CSS variables

:root {
  /* action color #CD8407 — the one interactive color; buttons/links/emphasis only, never large fills. */
  --bg: #E1D7C2;
  --surface: #D8CEBA;
  --border: #CAC2AF;
  --text: #4D4F46;
  --text-muted: #858275;
  --primary: #E1D7C2;  /* a neutral UI color (chips, tags, icon fills, chrome), not the action color (action = #CD8407). */
  --accent: #CD8407;  /* 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. */
  --link: #E3DFD1;  /* fails contrast on the background (~1.1:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference). */
  --secondary: #DDD6C5;  /* 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. */
  --button-bg: #CD8407;  /* primary-button fill — the main call-to-action color. */
  --button-text: #23251D;
  --font-heading: "Open Runde", "Newsreader", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: "IBM Plex Sans", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --text-hero: 36px; --weight-hero: 800; --leading-hero: 40px; --tracking-hero: -0.9px;
  --text-h2: 24px; --weight-h2: 700; --leading-h2: 32px; --tracking-h2: -0.6px;
  --text-h3: 21px; --weight-h3: 700; --leading-h3: 30px; --tracking-h3: -0.54px;
  --text-body: 15px; --weight-body: 400; --leading-body: 23px;
  --text-small: 14px; --weight-small: 600; --leading-small: 20px;
  --radius: 4px;
  --radius-button: 6px;
  --radius-card: 4px;
  --radius-pill: 9999px;
  --shadow-card: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(14, 18, 22, 0.35) 0px 10px 38px -10px, rgba(14, 18, 22, 0.2) 0px 10px 20px -15px;
  --shadow-subtle: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.25) 0px 25px 50px -12px;
  --focus-ring: 1px auto rgb(16, 16, 16);
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-fast: 150ms;
  --duration-base: 300ms;
  --duration-slow: 3000ms;
}

/* their own tokens, verbatim from the site's :root */
:root {
  --viewport-padding: 25px;
}
/* fonts: Open Runde may be proprietary — safe free fallback: Newsreader (Google Fonts). IBM Plex Sans — free, on Google. */