# DESIGN.md: v0-style design system

Measured from https://v0.app/ on 2026-10-15 by PikSpec (https://www.pikspec.com). An independent measurement of the rendered page, not v0's official design system, and not affiliated with v0.

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 v0.app, measured from the live site: it should feel designed by the same team as v0.app — the same temperament, colour, type and density — for a different product. Never use v0.app'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://v0.app/ — "v0.app" (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.
- It uses 596 images including 4 videos, 15 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: 27 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: 100% of the page is painted in #FAFAFA and #FFFFFF.
- The largest type (48px GeistSans) is semibold (600), tracked to -0.06em.
- Dense: text covers 25% of the page. Sections sit about 160px apart.
- Structure comes from thin grid lines, not from shadows or filled cards.
- Share of the painted page: #FAFAFA 56.7% (dominant, backgrounds); #FFFFFF 34.9% (dominant, backgrounds); #171717 3.5% (supporting, text); #666666 2.6% (supporting, text); #000000 0.8% (detail, drawings); #A8A8A8 0.7% (detail, drawings); #EBEBEB 0.7% (detail, backgrounds and lines). Keep accents at these proportions; do not promote them to fills.
- Hairline grid: 1px lines in #EBEBEB run both across and down the page (47 across, 26 down), dividing it into cells instead of cards.
- Illustrations: One large illustration in filled shapes, in #000000.
- Dashed lines: Dashed lines in #A8A8A8, drawn as routes or paths in the illustrations.
- Small marks: 5 small decorative marks (dots, crosses or ticks under 16px) in #171717, placed at corners and edges.
- Large images: Photographs, video or raster artwork cover about 139% of the page.
- Type as set (size, weight and tracking measured together; use these pairs): 48px weight 600 tracking -0.06em; 32px weight 600 tracking -0.04em; 24px weight 600 tracking -0.04em; 20px weight 600 tracking -0.02em; 18px weight 400; 16px weight 400.

1. DESIGN TOKENS — PASTE INTO YOUR GLOBAL CSS
Allowed colours, with how the original uses each. Use no other colour, including in hover states:
- #FAFAFA — 56.7% · backgrounds (var(--color-background))
- #FFFFFF — 34.9% · backgrounds (var(--color-ffffff))
- #171717 — 3.5% · text (var(--color-text))
- #666666 — 2.6% · text (var(--color-text-muted))
- #000000 — 0.8% · drawings (var(--color-000000))
- #A8A8A8 — 0.7% · drawings (var(--color-a8a8a8))
- #EBEBEB — 0.7% · backgrounds, lines (var(--color-surface))
- #C9C9C9 — hairlines and grid lines
- #E4E4E7 — Border (var(--color-border))
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=Inter:wght@400;500;600&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Geist+Mono:wght@400&display=swap");
```
Inter, GeistSans (Google's Geist) and GeistMono (Google's Geist Mono) are 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: #FAFAFA; /* Background */
  --color-surface: #EBEBEB; /* Surface */
  --color-text: #171717; /* Text */
  --color-text-muted: #666666; /* Text muted */
  --color-border: #E4E4E7; /* Border */
  --color-ffffff: #FFFFFF; /* 34.9% of the page, as fills */
  --color-000000: #000000; /* 0.8% of the page, as drawings */
  --color-a8a8a8: #A8A8A8; /* 0.7% of the page, as drawings */
  --font-body: "Inter", sans-serif; /* Inter */
  --font-display: "GeistSans", "Geist", sans-serif; /* GeistSans on the site; Geist renders */
  --font-code: "GeistMono", "Geist Mono", monospace; /* GeistMono on the site; Geist Mono renders */
  --type-display: 48px; /* Display, weight 600 */
  --type-display-leading: 56px;
  --type-display-tracking: -0.06em;
  --type-headline-large: 32px; /* Headline Large, weight 600 */
  --type-headline-large-leading: 40px;
  --type-headline-large-tracking: -0.04em;
  --type-headline-small: 24px; /* Headline Small, weight 600 */
  --type-headline-small-leading: 32px;
  --type-headline-small-tracking: -0.04em;
  --type-title-large: 20px; /* Title Large, weight 600 */
  --type-title-large-leading: 26px;
  --type-title-large-tracking: -0.02em;
  --type-title-small: 18px; /* Title Small, weight 400 */
  --type-title-small-leading: 28px;
  --type-body-large: 16px; /* Body Large, weight 400 */
  --type-body-large-leading: 24px;
  --type-body-small: 14px; /* Body Small, weight 500 */
  --type-body-small-leading: 20px;
  --type-label: 13px; /* Label, weight 400 */
  --type-label-leading: 13px;
  --space-2: 8px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-18: 72px;
  --space-20: 80px;
  --space-24: 96px;
  --space-32: 128px;
  --space-48: 192px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-2xl: 16px;
  --radius-full: 9999px;
  --elevation-1: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.08) 0px 0px 0px 1px;
  --elevation-2: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.08) 0px 0px 0px 1px, rgba(0, 0, 0, 0.04) 0px 2px 1px 0px;
  --elevation-3: rgba(0, 0, 0, 0.02) 0px 1px 1px 0px, rgba(0, 0, 0, 0.04) 0px 4px 8px -4px, rgba(0, 0, 0, 0.06) 0px 16px 24px -8px;
  --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) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.25) 0px 25px 50px -12px;
  --duration-1: 0.1s;
  --duration-2: 0.15s;
  --duration-3: 0.2s;
  --duration-4: 0.3s;
  --duration-5: 0.5s;
  --duration-6: 1s;
  --ease-1: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-2: cubic-bezier(0.31, 0.1, 0.08, 0.96);
  --ease-3: cubic-bezier(0, 0, 0.2, 1);
}
```
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: #FAFAFA;
  --color-surface: #EBEBEB;
  --color-text: #171717;
  --color-text-muted: #666666;
  --color-border: #E4E4E7;
  --color-ffffff: #FFFFFF;
  --color-000000: #000000;
  --color-a8a8a8: #A8A8A8;
  --font-body: "Inter", sans-serif;
  --font-display: "GeistSans", "Geist", sans-serif;
  --font-code: "GeistMono", "Geist Mono", monospace;
  --text-display: 48px;
  --text-display--line-height: 56px;
  --text-display--letter-spacing: -0.06em;
  --text-headline-large: 32px;
  --text-headline-large--line-height: 40px;
  --text-headline-large--letter-spacing: -0.04em;
  --text-headline-small: 24px;
  --text-headline-small--line-height: 32px;
  --text-headline-small--letter-spacing: -0.04em;
  --text-title-large: 20px;
  --text-title-large--line-height: 26px;
  --text-title-large--letter-spacing: -0.02em;
  --text-title-small: 18px;
  --text-title-small--line-height: 28px;
  --text-body-large: 16px;
  --text-body-large--line-height: 24px;
  --text-body-small: 14px;
  --text-body-small--line-height: 20px;
  --text-label: 13px;
  --text-label--line-height: 13px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-2xl: 16px;
  --radius-full: 9999px;
  --shadow-e1: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.08) 0px 0px 0px 1px;
  --shadow-e2: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.08) 0px 0px 0px 1px, rgba(0, 0, 0, 0.04) 0px 2px 1px 0px;
  --shadow-e3: rgba(0, 0, 0, 0.02) 0px 1px 1px 0px, rgba(0, 0, 0, 0.04) 0px 4px 8px -4px, rgba(0, 0, 0, 0.06) 0px 16px 24px -8px;
  --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) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.25) 0px 25px 50px -12px;
  --ease-1: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-2: cubic-bezier(0.31, 0.1, 0.08, 0.96);
  --ease-3: cubic-bezier(0, 0, 0.2, 1);
}
```
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)" },
  fontFamily: { "body": ["var(--font-body)"], "display": ["var(--font-display)"], "code": ["var(--font-code)"] },
  borderRadius: { "sm": "var(--radius-sm)", "md": "var(--radius-md)", "lg": "var(--radius-lg)", "xl": "var(--radius-xl)", "2xl": "var(--radius-2xl)", "full": "var(--radius-full)" },
  boxShadow: { "e1": "var(--elevation-1)", "e2": "var(--elevation-2)", "e3": "var(--elevation-3)", "e4": "var(--elevation-4)" },
}
```

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-display); margin: 0; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--color-text); outline-offset: 2px; }
```

3. COMPONENTS — MATCH THESE EXACTLY
```css
.link-2 { /* Inline 2 */
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 0px 12px 0px 12px;
  min-height: 32px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 20px;
  /* recorded states: focus-visible, disabled, hover, focus */
}
.link-3 { /* Inline 3 */
  background: transparent;
  border-radius: var(--radius-full);
  padding: 0px 12px 0px 12px;
  min-height: 32px;
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 20px;
  /* recorded states: focus-visible, disabled, hover, focus */
}
.nav { /* Default */
  background: transparent;
  min-height: 28px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-large);
  font-weight: 400;
  line-height: 24px;
}
.input { /* Default */
  background: transparent;
  padding: 0px 0px 8px 0px;
  min-height: 54px;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: var(--type-body-small);
  font-weight: 400;
  line-height: 20px;
}
.button { /* Tertiary */
  background: transparent;
  border-radius: var(--radius-full);
  padding: 0px 12px 0px 12px;
  min-height: 32px;
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 20px;
  /* recorded states: focus-visible, disabled, hover, focus */
}
.button-2 { /* Tertiary 2 */
  background: transparent;
  font-family: var(--font-body);
  font-size: var(--type-label);
  font-weight: 400;
  line-height: 13px;
}
.button-3 { /* Tertiary 3 */
  background: transparent;
  border-radius: var(--radius-full);
  padding: 0px 20px 0px 20px;
  min-height: 48px;
  font-family: var(--font-body);
  font-size: var(--type-body-large);
  font-weight: 500;
  line-height: 24px;
  /* recorded states: focus-visible, disabled, hover, focus */
}
```
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 #FAFAFA. 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 on the right. Leave a [content: hero image or video] slot there, at least half the screen wide; the opening is not text alone.
- Type: Inter for body; Geist for display; Geist Mono for code. Hierarchy comes from size and weight, not colour or decoration.
- Everything sits on a 8px grid.
- Corner radii are 4px, 6px, 8px, 12px, 16px, fully round (pill) — nothing else.
- Body text uses Inter at around 16px, weights 400, 500, 600.
- Headings use GeistSans; the largest heading is 48px.
- Spacing follows a 4px rhythm (1, 2, 4, 6, 8, 10, 12).
- Corner radii in use: 9999px (pill), 8px, 12px, 4px, 6px.

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 — 850px tall, a strip of 11 small items (logos, links or icons), centred 32px heading (weight 600), artwork on the right.
- Content sits in a 1264px container, 24px from the edge at 1440px wide.
- A 50px header scrolls away, transparent over the first section.
- The hero is 850px (0.9 screens): a strip of 11 small items (logos, links or icons), centred 32px heading (weight 600), artwork on the right.
- 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 6 words long.
- Section headings are short: typically 1 word.
- Headings are in sentence case (only the first word capitalised).
- The page describes itself in about 14 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 1264px wide, centred, with var(--space-4) (16px) side padding on small screens.
- The largest heading scales fluidly: font-size: clamp(24px, 3.3vw, 48px). 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 (17.2:1), Text muted on Background (5.5:1), Text on Surface (15:1) and Text muted on Surface (4.8:1).
- 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: #FAFAFA, #FFFFFF, #171717, #666666, #000000, #A8A8A8, #EBEBEB, #C9C9C9, #E4E4E7. 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.)
- Only the fonts in the tokens: Inter for body; Geist for display; Geist 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 Inter and GeistSans and GeistMono; the tokens carry what stands in for them.)
- Headings and large text never heavier than weight 600. Do not make headlines bold to add emphasis. (Every size from 24px up is set at weight 600 or lighter.)
- Large headlines tracked tight (letter-spacing -0.06em), not at the browser default. (The 48px headline is set at -0.06em.)
- No all-caps eyebrow labels above headings. (No uppercase text was measured.)
- 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), 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 v0.app'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.
- No text 24px or larger has a font-weight above 600.
- The largest headline uses letter-spacing -0.06em.
- Every section, including ones the original does not have, uses only this system's colours, type, shapes and spacing.
- Content sits in a 1264px container with 24px side margins at 1440px.
- 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.