# DESIGN.md: PostHog-style design system

Measured from https://posthog.com/ on 2026-10-14 by PikSpec (https://www.pikspec.com). An independent measurement of the rendered page, not PostHog's official design system, and not affiliated with PostHog.

Use it to build your own product in this design language: put this file in your project root and tell your AI tool (Claude Code, Cursor, Codex, Lovable, v0) to follow DESIGN.md. Never use the original's name, logo, copy or images; licensed fonts are replaced with the closest free Google Fonts.

To capture any other page, or get a ready project for your tool: https://www.pikspec.com/build-with-ai

HOW IT SHOULD LOOK
Build it in the design language of posthog.com, measured from the live site: it should feel designed by the same team as posthog.com — the same temperament, colour, type and density — for a different product. Never use posthog.com's name, logo, words or images.

Stack: use the one your project already has. Starting fresh: React + Vite + TypeScript + Tailwind CSS v4, with no UI kit (no shadcn/ui, MUI or Chakra) — their defaults would override this system. In a chat that shows one file (an artifact or canvas), build one HTML file instead, with the tokens below in its <style> block.
Use every value exactly as written. Do not round, rename, approximate or substitute a colour, size, radius, shadow or easing (fonts: see section 1). Anything not listed here does not exist in this system.

THE WEBSITE THIS SYSTEM COMES FROM
- Reference page: https://posthog.com/ — "posthog.com" (home page).
- Page frame: a top navigation bar, a persistent side panel beside the content and a footer. This is a tool- or docs-style layout, not a marketing page of stacked full-width bands.
- Content is grouped in cards (32 on the page). Keep cards for grouped content only, not for every section.
- It uses 36 images, 14 of them large. Large, real product imagery is part of the look — leave clearly labelled image slots at those sizes rather than stock photos or abstract 3D shapes.
- Interaction: 26 buttons on one page.
- The page runs about 5 screens long at 1440px wide.
- Density is moderate.

HOW IT LOOKS (WHAT MAKES IT LOOK LIKE ITSELF, BEYOND THE VALUES)
- Almost entirely neutral: 97% of the page is painted in #E5E7E0 and #EEEFE9.
- #320601 is an accent: 0.8% of the page, used for drawings only. Don't fill large areas with it.
- #B62AD9 is an accent: 0.7% of the page, as small fills such as buttons and badges. Keep it to small areas.
- The largest type (36px RoundHog) is bold (800), tracked to -0.025em.
- Dense: text covers 53% of the page.
- Structure comes from thin grid lines, not from shadows or filled cards.
- Share of the painted page: #E5E7E0 30% (dominant, backgrounds); #EEEFE9 24.7% (dominant, backgrounds); #FDFDF8 10.7% (dominant, backgrounds); #FFFFFF 9.8% (dominant, backgrounds); #000000 6.7% (dominant, backgrounds); #374151 5.4% (supporting, text); #F3F4EE 3.7% (detail, backgrounds); #111827 2.4% (supporting, text). Keep accents at these proportions; do not promote them to fills.
- Hairline grid: 1px lines in #BFC1B7 run both across and down the page (61 across, 11 down), dividing it into cells instead of cards.
- Illustrations: 2 large illustrations in filled shapes, in #320601, #A26045 and #FFFFFF.
- Small marks: 29 small decorative marks (dots, crosses or ticks under 16px) in #374151 and #6AA84F, placed at corners and edges.
- Large images: Photographs, video or raster artwork cover about 585% of the page.
- Type as set (size, weight and tracking measured together; use these pairs): 36px weight 800 tracking -0.025em; 30px weight 700 tracking -0.025em; 24px weight 700 tracking -0.025em; 20px weight 700 uppercase; 18px weight 500; 17px weight 500.

1. DESIGN TOKENS — PASTE INTO YOUR GLOBAL CSS
Allowed colours, with how the original uses each. Use no other colour, including in hover states:
- #E5E7E0 — 30% · backgrounds (var(--color-surface))
- #EEEFE9 — 24.7% · backgrounds (var(--color-eeefe9))
- #FDFDF8 — 10.7% · backgrounds (var(--color-fdfdf8))
- #FFFFFF — 9.8% · backgrounds (var(--color-background))
- #000000 — 6.7% · backgrounds (var(--color-000000))
- #374151 — 5.4% · text (var(--color-text-muted))
- #F3F4EE — 3.7% · backgrounds (var(--color-f3f4ee))
- #111827 — 2.4% · text
- #111111 — 2% · text (var(--color-text))
- #65675E — 1.6% · text
- #BFC1B7 — hairlines and grid lines (var(--color-border))
- #B17816 — hairlines and grid lines (var(--color-warning))
- #6AA84F — small marks
- #2F80FA — small marks
- #F7A501 — small marks
- #CD8407 — Action (var(--color-action))
- #23251D — On action (var(--color-on-action))
- #30ABC6 — Positive (var(--color-positive))
- #F35454 — Negative (var(--color-negative))
Fonts — put these first in your global CSS (one import per font, so one that fails cannot stop the others):
```css
@import url("https://fonts.googleapis.com/css2?family=Figtree:wght@400;500;600;700;800&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Source+Code+Pro:wght@500&display=swap");
```
Font: posthog.com uses RoundHog (body) — its own licensed face, not available to download. This kit uses Figtree for body, the closest free match, already in the tokens. If you own the original, add it with @font-face and it is used first; to use another font, change the --font-* variables.
Source Code Pro is on Google Fonts and loaded from there.
Keep every size, weight, line height and tracking exactly as listed whichever font renders.
```css
:root {
  --color-background: #FFFFFF; /* Background */
  --color-surface: #E5E7E0; /* Surface */
  --color-text: #111111; /* Text */
  --color-text-muted: #374151; /* Text muted */
  --color-border: #BFC1B7; /* Border */
  --color-action: #CD8407; /* Action */
  --color-on-action: #23251D; /* On action */
  --color-positive: #30ABC6; /* Positive */
  --color-negative: #F35454; /* Negative */
  --color-warning: #B17816; /* Warning */
  --color-eeefe9: #EEEFE9; /* 24.7% of the page, as fills */
  --color-fdfdf8: #FDFDF8; /* 10.7% of the page, as fills */
  --color-000000: #000000; /* 6.7% of the page, as fills */
  --color-f3f4ee: #F3F4EE; /* 3.7% of the page, as fills */
  --color-320601: #320601; /* 0.8% of the page, as drawings */
  --color-b62ad9: #B62AD9; /* 0.7% of the page, as fills */
  --color-eb9d2a: #EB9D2A; /* 0.6% of the page, as fills */
  --font-body: "RoundHog", "Figtree", sans-serif; /* RoundHog on the site; Figtree renders */
  --font-code: "Source Code Pro", monospace; /* Source Code Pro */
  --type-display: 36px; /* Display, weight 800 */
  --type-display-leading: 40px;
  --type-display-tracking: -0.025em;
  --type-headline-large: 30px; /* Headline Large, weight 700 */
  --type-headline-large-leading: 40px;
  --type-headline-large-tracking: -0.025em;
  --type-headline-small: 24px; /* Headline Small, weight 700 */
  --type-headline-small-leading: 32px;
  --type-headline-small-tracking: -0.025em;
  --type-title-large: 20px; /* Title Large, weight 700 */
  --type-title-large-leading: 28px;
  --type-title-small: 18px; /* Title Small, weight 500 */
  --type-title-small-leading: 27px;
  --type-body-large: 17px; /* Body Large, weight 500 */
  --type-body-large-leading: 25.5px;
  --type-body-medium: 15px; /* Body Medium, weight 500 */
  --type-body-medium-leading: 26.6667px;
  --type-body-small: 14px; /* Body Small, weight 600 */
  --type-body-small-leading: 20px;
  --type-label-1: 13.86px; /* Label 1, weight 600 */
  --type-label-1-leading: 19.3985px;
  --type-label-2: 13.34px; /* Label 2, weight 500 */
  --type-label-2-leading: 18.68px;
  --type-label-3: 13px; /* Label 3, weight 500 */
  --type-label-3-leading: 16.25px;
  --type-label-4: 12px; /* Label 4, weight 500 */
  --type-label-4-leading: 18px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-7: 28px;
  --space-8: 32px;
  --space-12: 48px;
  --space-14: 56px;
  --space-16: 64px;
  --space-18: 72px;
  --space-20: 80px;
  --space-24: 96px;
  --space-28: 112px;
  --radius-xs: 2px;
  --radius-sm: 3.59231px;
  --radius-md: 4px;
  --radius-lg: 5.64506px;
  --radius-xl: 6px;
  --radius-2xl: 6.67144px;
  --radius-3xl: 7.69781px;
  --radius-full: 9999px;
  --radius-8: 8px; /* component radius */
  --elevation-1: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgb(210, 211, 204) 0px 2.30934px 0px 0px;
  --elevation-2: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgb(210, 211, 204) 0px 2.82253px 0px 0px;
  --elevation-3: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(255, 255, 255, 0.4) 0px 0px 6px 2px;
  --elevation-4: 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 4px 6px -1px, rgba(0, 0, 0, 0.1) 0px 2px 4px -2px;
  --elevation-5: 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;
  --elevation-6: 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;
  --duration-1: 0.15s;
  --duration-2: 0.2s;
  --duration-3: 0.3s;
  --duration-4: 0.35s;
  --duration-5: 0.4s;
  --duration-6: 0.7s;
  --ease-1: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-2: ease-out;
}
```
Tailwind CSS v4 (the default for new projects): put this after `@import "tailwindcss";`. It removes Tailwind's own palette, so only these colours exist as utilities:
```css
@theme {
  --color-*: initial;
  --color-background: #FFFFFF;
  --color-surface: #E5E7E0;
  --color-text: #111111;
  --color-text-muted: #374151;
  --color-border: #BFC1B7;
  --color-action: #CD8407;
  --color-on-action: #23251D;
  --color-positive: #30ABC6;
  --color-negative: #F35454;
  --color-warning: #B17816;
  --color-eeefe9: #EEEFE9;
  --color-fdfdf8: #FDFDF8;
  --color-000000: #000000;
  --color-f3f4ee: #F3F4EE;
  --color-320601: #320601;
  --color-b62ad9: #B62AD9;
  --color-eb9d2a: #EB9D2A;
  --font-body: "RoundHog", "Figtree", sans-serif;
  --font-code: "Source Code Pro", monospace;
  --text-display: 36px;
  --text-display--line-height: 40px;
  --text-display--letter-spacing: -0.025em;
  --text-headline-large: 30px;
  --text-headline-large--line-height: 40px;
  --text-headline-large--letter-spacing: -0.025em;
  --text-headline-small: 24px;
  --text-headline-small--line-height: 32px;
  --text-headline-small--letter-spacing: -0.025em;
  --text-title-large: 20px;
  --text-title-large--line-height: 28px;
  --text-title-small: 18px;
  --text-title-small--line-height: 27px;
  --text-body-large: 17px;
  --text-body-large--line-height: 25.5px;
  --text-body-medium: 15px;
  --text-body-medium--line-height: 26.6667px;
  --text-body-small: 14px;
  --text-body-small--line-height: 20px;
  --text-label-1: 13.86px;
  --text-label-1--line-height: 19.3985px;
  --text-label-2: 13.34px;
  --text-label-2--line-height: 18.68px;
  --text-label-3: 13px;
  --text-label-3--line-height: 16.25px;
  --text-label-4: 12px;
  --text-label-4--line-height: 18px;
  --radius-xs: 2px;
  --radius-sm: 3.59231px;
  --radius-md: 4px;
  --radius-lg: 5.64506px;
  --radius-xl: 6px;
  --radius-2xl: 6.67144px;
  --radius-3xl: 7.69781px;
  --radius-full: 9999px;
  --shadow-e1: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgb(210, 211, 204) 0px 2.30934px 0px 0px;
  --shadow-e2: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgb(210, 211, 204) 0px 2.82253px 0px 0px;
  --shadow-e3: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(255, 255, 255, 0.4) 0px 0px 6px 2px;
  --shadow-e4: 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 4px 6px -1px, rgba(0, 0, 0, 0.1) 0px 2px 4px -2px;
  --shadow-e5: 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;
  --shadow-e6: 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;
  --ease-1: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-2: ease-out;
}
```
Tailwind CSS v3 only: extend the theme with these instead, and use no other palette:
```js
// tailwind.config — theme.extend
{
  colors: { "background": "var(--color-background)", "surface": "var(--color-surface)", "text": "var(--color-text)", "text-muted": "var(--color-text-muted)", "border": "var(--color-border)", "action": "var(--color-action)", "on-action": "var(--color-on-action)", "positive": "var(--color-positive)", "negative": "var(--color-negative)", "warning": "var(--color-warning)" },
  fontFamily: { "body": ["var(--font-body)"], "code": ["var(--font-code)"] },
  borderRadius: { "xs": "var(--radius-xs)", "sm": "var(--radius-sm)", "md": "var(--radius-md)", "lg": "var(--radius-lg)", "xl": "var(--radius-xl)", "2xl": "var(--radius-2xl)", "3xl": "var(--radius-3xl)", "full": "var(--radius-full)" },
  boxShadow: { "e1": "var(--elevation-1)", "e2": "var(--elevation-2)", "e3": "var(--elevation-3)", "e4": "var(--elevation-4)", "e5": "var(--elevation-5)", "e6": "var(--elevation-6)" },
}
```

2. BASE STYLES
```css
html { background: var(--color-background); }
body { margin: 0; font-family: var(--font-body); font-size: var(--type-body-large); line-height: var(--type-body-large-leading); color: var(--color-text); -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
h1, h2, h3 { font-family: var(--font-body); margin: 0; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--color-action); outline-offset: 2px; }
```

3. COMPONENTS — MATCH THESE EXACTLY
```css
.card { /* Default */
  border-radius: 0px 6px 6px;
  padding: var(--space-2);
  min-height: 466px;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 500;
  line-height: 32px;
}
.card-2 { /* Alternative 1 */
  background: var(--color-background);
  border-radius: var(--radius-md);
  min-height: 450px;
  box-shadow: var(--elevation-5);
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 500;
  line-height: 32px;
}
.card-3 { /* Alternative 2 */
  background: var(--color-fdfdf8);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  min-height: 209px;
  box-shadow: var(--elevation-5);
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 500;
  line-height: 32px;
}
.link { /* Strong */
  background: transparent;
  color: #111827;
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 600;
  line-height: 27px;
}
.link-2 { /* Strong 2 */
  background: transparent;
  border-radius: var(--radius-md);
  padding: 6px 8px 6px 8px;
  min-height: 46px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-medium);
  font-weight: 600;
  line-height: 26.6667px;
  /* recorded states: hover, focus, active, disabled */
}
.link-3 { /* Strong 3 */
  background: transparent;
  color: #111827;
  font-family: var(--font-body);
  font-size: var(--type-label-4);
  font-weight: 600;
  line-height: 16px;
}
.button { /* Primary */
  background: var(--color-action);
  border: 1px solid #B17816;
  border-radius: var(--radius-xl);
  min-height: 32px;
  color: var(--color-on-action);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 24px;
  /* recorded states: hover, disabled */
}
.button-2 { /* Secondary */
  border-radius: 6px 6px 0px 0px;
  padding: 10px 12px 10px 12px;
  min-height: 40px;
  color: #FFFFFF;
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 600;
  line-height: 20px;
  /* recorded states: selected */
}
.button-3 { /* Secondary 2 */
  background: var(--color-action);
  border: 1px solid #B17816;
  border-radius: var(--radius-8);
  min-height: 47px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 500;
  line-height: 32px;
  /* recorded states: disabled */
}
```
Where a component lists recorded states, write those states using only the colours above; the capture saw that the state exists, not its values. Never invent a state colour.

4. PAGE COMPOSITION
- Light interface on #FFFFFF. Keep that ground; do not add a dark mode or alternate section backgrounds the system does not have.
- The opening screen carries a large image or video behind or across the heading. Leave a [content: hero image or video] slot there, at least half the screen wide; the opening is not text alone.
- #CD8407 is the action colour. Fill the primary action with it and little else — at most one #CD8407-filled element per screen; other accents keep to the uses listed above.
- Type: Figtree (standing in for RoundHog) for body; Source Code Pro for code. Hierarchy comes from size and weight, not colour or decoration.
- Everything sits on a 4px grid.
- Corner radii are 2px, 3.59231px, 4px, 5.64506px, 6px, 6.67144px, 7.69781px, fully round (pill) — nothing else.
- Body text uses RoundHog at around 15.4px, weights 400, 500, 600, 700, 800.
- Headings use the same family as body text; the largest heading is 36px.
- Primary buttons are #CD8407, 6px radius, weight 400.
- Cards use 4px corners with a soft shadow.
- Corner radii in use: 4px, 2px, 9999px (pill), 6px, 5.64506px.

HOW THE ORIGINAL PACES ITS PAGE (BORROW THE RHYTHM — THE OPENING, THE COLOURED BANDS, THE CARD GRIDS — NOT THE LIST; BUILD THE SECTIONS YOUR PRODUCT NEEDS)
1. Hero — 844px tall, 3 equal columns, left-aligned 36px heading (weight 800), artwork behind the content, on an image background.
- The hero is 844px (0.9 screens): 3 equal columns, left-aligned 36px heading (weight 800), artwork behind the content, on an image background.
- Column splits on a 12-column grid: thirds.
- Sections share one background; they are separated by space and lines, not colour bands.

COPY SHAPE (MATCH THE LENGTH AND CASE; WRITE YOUR OWN WORDS)
- The main heading is 4 words long.
- Section headings are short: typically 2 words.
- Headings are in sentence case (only the first word capitalised).
- The page describes itself in about 18 words; keep your intro paragraph to about that length.

5. MOTION
Interactive elements change colour, background, border and opacity with the measured timing. Animate nothing else.
```css
a, button, [role="button"], input { transition: color var(--duration-1) var(--ease-1), background-color var(--duration-1) var(--ease-1), border-color var(--duration-1) var(--ease-1), opacity var(--duration-1) var(--ease-1); }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}
```
No scroll-triggered fade-ins, parallax, typewriter text or bouncing elements.

6. RESPONSIVE
- The design was measured at 1440px wide. Lay it out for that width first, then let it reflow down to 360px.
- Side padding on small screens: var(--space-4) (16px).
- The largest heading scales fluidly: font-size: clamp(20px, 2.5vw, 36px). Every other size stays fixed.
- Break on composition, not device names: a row of columns drops a column when any column would be narrower than 240px; side-by-side splits stack when either side would be narrower than 320px.
- Spacing steps never change between sizes; use smaller steps from the same list where space is tight.
- On touch screens, every link and button has a hit area of at least 44 × 44px without changing its drawn size.

7. ACCESSIBILITY
- Text pairs that pass for body copy: Text on Background (18.9:1), Text muted on Background (10.3:1), Text on Surface (15.1:1), Text muted on Surface (8.3:1) and On action on Action (5.1:1).
- Only for text 24px and up, or 18.66px bold: Action on Background (3:1) and Negative on Background (3.4:1).
- Use no other text-on-background pairing.
- One h1 per page, headings in order, landmarks (header, nav, main, footer), real buttons and links, a label on every field, alt text on every image, an aria-label on icon-only buttons.
- Every interactive element shows the :focus-visible outline above.

8. DO NOT (THESE ARE WHAT MAKE AI-BUILT SITES LOOK GENERIC)
- No gradients: not in backgrounds, text, buttons or borders. (No gradient was measured.)
- Only these colours: #E5E7E0, #EEEFE9, #FDFDF8, #FFFFFF, #000000, #374151, #F3F4EE, #111827, #111111, #65675E, #BFC1B7, #B17816, #6AA84F, #2F80FA, #F7A501, #CD8407, #23251D, #30ABC6, #F35454. No new tints, no Tailwind defaults (slate, indigo, violet). (They are every colour that covers a measurable part of the page, and the colours its lines and drawings use.)
- #320601 only for drawings — never as a section background or a large panel. (It covers 0.8% of the page.)
- #B62AD9 only as small fills (buttons, badges) — never a section background or a large panel. (It covers 0.7% of the page.)
- Only the fonts in the tokens: Figtree for body; Source Code Pro for code. No other typeface, and no Inter, Roboto or system UI font unless it is one of these. (The page is set in RoundHog and Source Code Pro; the tokens carry what stands in for them.)
- The largest headlines are heavy (weight 800). Keep them that heavy, and keep smaller text at the weights in the type scale. (The page sets its biggest type at 800.)
- Large headlines tracked tight (letter-spacing -0.025em), not at the browser default. (The 36px headline is set at -0.025em.)
- No icon above every feature, no emoji, no decorative blobs, sparkles or glows. (None of these is part of the captured design; they are a coding model's defaults.)
- The hero is left-aligned. Do not centre it. (The captured hero sets its heading on the left.)
- Build the sections your product needs, not the original's list. Give each one this system's look: its kinds of section (hero), its colours, type, shapes and spacing. (The style carries to any kind of site; the original's page was for a different product.)
- No glassmorphism, backdrop blur, glowing orbs, noise blobs or neon outlines.
- No row of three identical feature cards as the default section. Vary the layout from section to section: a split, a list, a single large statement, a table.
- No centred-everything hero with a pill badge, a gradient headline and two buttons. Lead with the most specific thing about the product.
- No filler copy: no "Unlock your potential", "Revolutionize", "Seamless", "Elevate", "Supercharge", "Next-gen" or lorem ipsum. Write plain, specific sentences a real company would publish.
- No made-up statistics, testimonials or customer logos. Leave a clearly marked [content: …] slot instead.
- No radius larger than the largest one listed.
- No shadows other than the levels listed.
- Do not use posthog.com's name, logo, copy or images. This is its design system, not its content.

BEFORE YOU FINISH
- Search your code for every colour, font size, spacing value, radius, shadow and easing, and replace anything that is not a variable above.
- Check that no [content: …] slot has been filled with invented facts.
- Search your CSS for gradient(. There should be none.
- Every colour value in your CSS is one of the allowed colours. Nothing else, including in hover states.
- #320601 covers about 0.8% of the page or less, as on the original.
- #B62AD9 covers about 0.7% of the page or less, as on the original.
- The largest headline is set at weight 800.
- The largest headline uses letter-spacing -0.025em.
- Every section, including ones the original does not have, uses only this system's colours, type, shapes and spacing.
- There is no placeholder copy (lorem ipsum, "Feature one", "Your headline here"). Every word is real.
- Take a screenshot at 1440px and put it beside the original. List every difference in colour, weight, spacing, alignment and imagery, and fix each before finishing. Then check 390px wide: nothing scrolls sideways and no heading runs off the screen.