# DESIGN.md: Datadog-style design system

Measured from https://www.datadoghq.com/ on 2026-10-15 by PikSpec (https://www.pikspec.com). An independent measurement of the rendered page, not Datadog's official design system, and not affiliated with Datadog.

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 datadoghq.com, measured from the live site: it should feel designed by the same team as datadoghq.com — the same temperament, colour, type and density — for a different product. Never use datadoghq.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://www.datadoghq.com/ — "www.datadoghq.com" (home page).
- Page frame: a top navigation bar and a footer.
- It uses 209 images including 20 videos, 55 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: 18 buttons and 1 form field on one page.
- The page runs about 6 screens long at 1440px wide.
- Density is moderate.

HOW IT LOOKS (WHAT MAKES IT LOOK LIKE ITSELF, BEYOND THE VALUES)
- Almost entirely neutral: 99% of the page is painted in #FFFFFF and #110617.
- #632CA6 is an accent: 0.2% of the page, used for backgrounds and text and small fills such as buttons. Don't fill large areas with it.
- #8000FF is an accent: under 0.1% of the page, used for text only. Don't fill large areas with it.
- The largest type (68px NationalWeb) is semibold (600).
- Balanced: text covers 12% of the page.
- Share of the painted page: #FFFFFF 72.5% (dominant, backgrounds); #110617 12.4% (supporting, backgrounds); #000000 7% (supporting, backgrounds); #F6F6F6 4.3% (supporting, backgrounds); #212529 2.2% (supporting, text); #E2E2E2 1.2% (supporting, text); #632CA6 0.2% (accent, backgrounds and text); #969696 0.1% (detail, text). Keep accents at these proportions; do not promote them to fills.
- Hairline dividers: 1px lines in #FFFFFF separate sections and rows (20 of them).
- Large images: Photographs, video or raster artwork cover about 113% of the page.
- Type as set (size, weight and tracking measured together; use these pairs): 68px weight 600; 36px weight 700; 32px weight 300; 22px weight 300; 20px weight 600; 18px weight 300.

1. DESIGN TOKENS — PASTE INTO YOUR GLOBAL CSS
Allowed colours, with how the original uses each. Use no other colour, including in hover states:
- #FFFFFF — 72.5% · backgrounds (var(--color-background))
- #110617 — 12.4% · backgrounds (var(--color-110617))
- #000000 — 7% · backgrounds (var(--color-000000))
- #F6F6F6 — 4.3% · backgrounds (var(--color-surface))
- #212529 — 2.2% · text (var(--color-text))
- #E2E2E2 — 1.2% · text (var(--color-border))
- #632CA6 — 0.2% · backgrounds, text (var(--color-action))
- #969696 — 0.1% · text
- #555555 — 0.1% · text (var(--color-text-muted))
- #616161 — hairlines and grid lines
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@300;400;500;600;700&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Inter+Tight:wght@300;600&display=swap");
@import url("https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400&display=swap");
```
Font: datadoghq.com uses NationalWeb (body), Helvetica (interface) and RobotoMono-Regular (code) — its own licensed faces, not available to download. This kit uses Figtree for body, Inter Tight for interface and JetBrains Mono for code, the closest free matches, 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.
Keep every size, weight, line height and tracking exactly as listed whichever font renders.
```css
:root {
  --color-background: #FFFFFF; /* Background */
  --color-surface: #F6F6F6; /* Surface */
  --color-text: #212529; /* Text */
  --color-text-muted: #555555; /* Text muted */
  --color-border: #E2E2E2; /* Border */
  --color-action: #632CA6; /* Action */
  --color-on-action: #FFFFFF; /* On action */
  --color-110617: #110617; /* 12.4% of the page, as fills */
  --color-000000: #000000; /* 7% of the page, as fills */
  --font-body: "NationalWeb", "Figtree", sans-serif; /* NationalWeb on the site; Figtree renders */
  --font-interface: "Helvetica", "Inter Tight", sans-serif; /* Helvetica on the site; Inter Tight renders */
  --font-code: "RobotoMono-Regular", "JetBrains Mono", monospace; /* RobotoMono-Regular on the site; JetBrains Mono renders */
  --type-display-large: 68px; /* Display Large, weight 600 */
  --type-display-large-leading: 68px;
  --type-display-small: 36px; /* Display Small, weight 700 */
  --type-display-small-leading: 40px;
  --type-headline: 32px; /* Headline, weight 300 */
  --type-headline-leading: 38px;
  --type-title-large: 22px; /* Title Large, weight 300 */
  --type-title-large-leading: 30px;
  --type-title-medium: 20px; /* Title Medium, weight 600 */
  --type-title-medium-leading: normal;
  --type-title-small: 18px; /* Title Small, weight 300 */
  --type-title-small-leading: 22px;
  --type-body-large: 16px; /* Body Large, weight 700 */
  --type-body-large-leading: 20px;
  --type-body-small: 14px; /* Body Small, weight 300 */
  --type-body-small-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-9: 36px;
  --space-10: 40px;
  --space-12: 48px;
  --space-13: 52px;
  --space-15: 60px;
  --space-16: 64px;
  --space-17: 68px;
  --space-20: 80px;
  --space-21: 84px;
  --space-25: 100px;
  --space-35: 140px;
  --radius-xs: 1px;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 4.8px;
  --radius-xl: 6px;
  --radius-full: 9999px;
  --elevation-1: rgba(0, 0, 0, 0.07) 0px 0px 8px 8px;
  --duration-1: 0.15s;
  --duration-2: 0.2s;
  --ease-1: ease-in-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: #F6F6F6;
  --color-text: #212529;
  --color-text-muted: #555555;
  --color-border: #E2E2E2;
  --color-action: #632CA6;
  --color-on-action: #FFFFFF;
  --color-110617: #110617;
  --color-000000: #000000;
  --font-body: "NationalWeb", "Figtree", sans-serif;
  --font-interface: "Helvetica", "Inter Tight", sans-serif;
  --font-code: "RobotoMono-Regular", "JetBrains Mono", monospace;
  --text-display-large: 68px;
  --text-display-large--line-height: 68px;
  --text-display-small: 36px;
  --text-display-small--line-height: 40px;
  --text-headline: 32px;
  --text-headline--line-height: 38px;
  --text-title-large: 22px;
  --text-title-large--line-height: 30px;
  --text-title-medium: 20px;
  --text-title-small: 18px;
  --text-title-small--line-height: 22px;
  --text-body-large: 16px;
  --text-body-large--line-height: 20px;
  --text-body-small: 14px;
  --text-body-small--line-height: 18px;
  --radius-xs: 1px;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 4.8px;
  --radius-xl: 6px;
  --radius-full: 9999px;
  --shadow-e1: rgba(0, 0, 0, 0.07) 0px 0px 8px 8px;
  --ease-1: ease-in-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)" },
  fontFamily: { "body": ["var(--font-body)"], "interface": ["var(--font-interface)"], "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)", "full": "var(--radius-full)" },
  boxShadow: { "e1": "var(--elevation-1)" },
}
```

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
.link { /* Inline */
  background: transparent;
  min-height: 52px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-title-large);
  font-weight: 300;
  line-height: 31.4286px;
  /* recorded states: focus, active, hover */
}
.link-2 { /* Strong */
  background: transparent;
  padding: 9px 12px 10px 12px;
  min-height: 44px;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 600;
  line-height: 25.7143px;
  /* recorded states: focus, active, hover */
}
.nav { /* Default */
  background: var(--color-background);
  box-shadow: var(--elevation-1);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-title-large);
  font-weight: 300;
  line-height: 31.4286px;
}
.button { /* Primary */
  background: var(--color-action);
  border-radius: var(--radius-md);
  padding: 16px 24px 16px 24px;
  min-height: 54px;
  color: var(--color-on-action);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 700;
  line-height: 18px;
  /* recorded states: focus, active, hover, focus-visible, disabled */
}
.button-2 { /* Secondary */
  background: var(--color-background);
  border-radius: var(--radius-md);
  padding: 9px 28px 10px 28px;
  min-height: 44px;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--type-title-small);
  font-weight: 600;
  line-height: 25.7143px;
  /* recorded states: focus, active, hover, focus-visible, disabled */
}
.button-3 { /* Secondary 2 */
  background: var(--color-background);
  border-radius: var(--radius-md);
  padding: 16px 24px 16px 24px;
  min-height: 51px;
  color: var(--color-000000);
  font-family: var(--font-body);
  font-size: var(--type-title-large);
  font-weight: 300;
  line-height: 31.4286px;
  /* recorded states: focus, active, hover */
}
.input { /* Default */
  background: transparent;
  padding: 0px 10px 0px 10px;
  min-height: 49px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-headline);
  font-weight: 300;
  line-height: 49px;
  /* recorded states: focus, active */
}
```
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.
- 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.
- Sections change ground between Background (#FFFFFF), #000000 and #110617; use only those.
- #632CA6 is the action colour. Fill the primary action with it and little else — at most one #632CA6-filled element per screen; other accents keep to the uses listed above.
- Type: Figtree (standing in for NationalWeb) for body; Inter Tight (standing in for Helvetica) for interface; JetBrains Mono (standing in for RobotoMono-Regular) for code. Hierarchy comes from size and weight, not colour or decoration.
- Everything sits on a 4px grid.
- Corner radii are 1px, 3px, 4px, 4.8px, 6px, fully round (pill) — nothing else.
- Body text uses NationalWeb at around 16px, weights 300, 400, 500, 600, 700.
- Headings use the same family as body text; the largest heading is 68px.
- Primary buttons are #632CA6, 4px radius, weight 700.
- Corner radii in use: 4px, 6px, 1px, 4.8px, 800px.

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 — 1050px tall, centred 68px heading (weight 600), full-width image.
2. Text — 467px tall, left-aligned 36px heading (weight 700), image on the right.
3. Full-bleed image — 310px tall, left-aligned 36px heading (weight 600), image behind the content, on an image background.
4. Grid — 764px tall, 3 items in 2 columns with 84px gaps, left-aligned 36px heading (weight 600), image on the right, on #000000.
5. Text — 366px tall, left-aligned 36px heading (weight 700), image on the right.
6. Text — 467px tall, left-aligned 36px heading (weight 700), image on the left.
7. Text — 468px tall, left-aligned 36px heading (weight 700), image on the right, on #F6F6F6.
8. Full-bleed image — 305px tall, centred 36px heading (weight 700), image behind the content, on an image background.
9. Full-bleed image — 288px tall, centred 36px heading (weight 300), image behind the content.
10. Footer — 1004px tall, split 8 / 4, left-aligned 18px heading (weight 700).
- Content runs 1340px wide with 64px side margins at 1440px; there is no narrower centred container.
- A 130px header stays fixed at the top.
- The hero is 1050px (1.2 screens): centred 68px heading (weight 600), full-width image.
- Column splits on a 12-column grid: 4/8, 8/4; gaps of 84px.
- Headings align left (7 of 10 sections); centre only the occasional statement.
- Sections change background 4 times, between #000000, #F6F6F6: colour comes in full-width bands, not in boxes.
- A typical section is about 467px tall.

COPY SHAPE (MATCH THE LENGTH AND CASE; WRITE YOUR OWN WORDS)
- The main heading is 4 words long.
- Section headings are long: typically 13 words.
- Heading case varies.
- The page describes itself in about 10 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.
- Content sits in a column at most 1342px wide, centred, with var(--space-4) (16px) side padding on small screens.
- The largest heading scales fluidly: font-size: clamp(36px, 4.7vw, 68px). 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 (15.4:1), Text muted on Background (7.5:1), Action on Background (8.6:1), Text on Surface (14.3:1), Text muted on Surface (6.9:1), Action on Surface (8:1) and On action on Action (8.6:1).
- 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)
- Only the one shadow in the tokens, on the components that use them. (1 shadow value was measured; inventing softer ones changes the depth of the page.)
- No gradients: not in backgrounds, text, buttons or borders. (No gradient was measured.)
- Only these colours: #FFFFFF, #110617, #000000, #F6F6F6, #212529, #E2E2E2, #632CA6, #969696, #555555, #616161. 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.)
- #632CA6 only for backgrounds and text and small fills such as buttons — never as a section background or a large panel. (It covers 0.2% of the page.)
- #8000FF only for text — never as a section background or a large panel. (It covers under 0.1% of the page.)
- Only the fonts in the tokens: Figtree for body; Inter Tight for interface; JetBrains Mono for code. No other typeface, and no Inter, Roboto or system UI font unless it is one of these. (The page is set in NationalWeb and RobotoMono-Regular; the tokens carry what stands in for them.)
- Headings and large text never heavier than weight 700. Do not make headlines bold to add emphasis. (Every size from 24px up is set at weight 700 or lighter.)
- 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.)
- Build the sections your product needs, not the original's list. Give each one this system's look: its kinds of section (hero, text, image, grid, footer), 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.
- Do not use datadoghq.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.
- #632CA6 covers about 0.2% of the page or less, as on the original.
- #8000FF covers about 0.1% of the page or less, as on the original.
- No text 24px or larger has a font-weight above 700.
- 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.