# DESIGN.md: Squarespace-style design system

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

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 squarespace.com, measured from the live site: it should feel designed by the same team as squarespace.com — the same temperament, colour, type and density — for a different product. Never use squarespace.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.squarespace.com/ — "www.squarespace.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.
- It uses 1024 images including 27 videos, 53 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: 53 buttons on one page.
- The page runs about 9 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 #000000 and #FFFFFF.
- The largest type (64px Clarkson) is light, not bold (300), tracked to -0.06em.
- Very airy: text covers 5% of the page.
- Share of the painted page: #000000 77.6% (dominant, backgrounds); #FFFFFF 19.7% (dominant, backgrounds); #2F2F2F 2.2% (detail, backgrounds); #898989 0.4% (supporting, text). Keep accents at these proportions; do not promote them to fills.
- Large images: Photographs, video or raster artwork cover about 66% of the page.
- Type as set (size, weight and tracking measured together; use these pairs): 64px weight 300 tracking -0.06em; 56px weight 300 tracking -0.04em; 40px weight 400 tracking -0.04em; 26px weight 400 tracking -0.02em; 20px weight 500 tracking -0.01em; 15px weight 400 tracking -0.001em.

1. DESIGN TOKENS — PASTE INTO YOUR GLOBAL CSS
Allowed colours, with how the original uses each. Use no other colour, including in hover states:
- #000000 — 77.6% · backgrounds (var(--color-background))
- #FFFFFF — 19.7% · backgrounds (var(--color-text))
- #2F2F2F — 2.2% · backgrounds (var(--color-action))
- #898989 — 0.4% · text (var(--color-text-muted))
- #E7E7E7 — Border (var(--color-border))
- #1E4C41 — Positive (var(--color-positive))
- #200603 — 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@300;400;500;700&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Source+Serif+4:wght@300;400&display=swap");
```
Font: squarespace.com uses Clarkson (body) and Clarkson Serif (interface) — its own licensed faces, not available to download. This kit uses Figtree for body and Source Serif 4 for interface, 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: #000000; /* Background */
  --color-text: #FFFFFF; /* Text */
  --color-text-muted: #898989; /* Text muted */
  --color-border: #E7E7E7; /* Border */
  --color-action: #2F2F2F; /* Action */
  --color-on-action: #FFFFFF; /* On action */
  --color-positive: #1E4C41; /* Positive */
  --color-negative: #200603; /* Negative */
  --font-body: "Clarkson", "Figtree", sans-serif; /* Clarkson on the site; Figtree renders */
  --font-interface: "Clarkson Serif", "Source Serif 4", serif; /* Clarkson Serif on the site; Source Serif 4 renders */
  --type-display-large: 64px; /* Display Large, weight 300 */
  --type-display-large-leading: 66.5601px;
  --type-display-large-tracking: -0.06em;
  --type-display-medium: 56px; /* Display Medium, weight 300 */
  --type-display-medium-leading: 60.48px;
  --type-display-medium-tracking: -0.04em;
  --type-display-small: 40px; /* Display Small, weight 400 */
  --type-display-small-leading: 43.2px;
  --type-display-small-tracking: -0.04em;
  --type-headline: 26px; /* Headline, weight 400 */
  --type-headline-leading: 28.08px;
  --type-headline-tracking: -0.02em;
  --type-title: 20px; /* Title, weight 500 */
  --type-title-leading: 24px;
  --type-title-tracking: -0.01em;
  --type-body-large: 15px; /* Body Large, weight 400 */
  --type-body-large-leading: 21px;
  --type-body-large-tracking: -0.001em;
  --type-body-small: 14px; /* Body Small, weight 500 */
  --type-body-small-leading: 14px;
  --type-label-large: 13px; /* Label Large, weight 400 */
  --type-label-large-leading: normal;
  --type-label-small: 12px; /* Label Small, weight 400 */
  --type-label-small-leading: 16.8px;
  --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-10: 40px;
  --space-12: 48px;
  --space-14: 56px;
  --space-16: 64px;
  --space-20: 80px;
  --space-30: 120px;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 8px;
  --radius-xl: 16px;
  --radius-3xl: 30px;
  --radius-full: 9999px;
  --elevation-1: color(srgb 0 0 0 / 0.2) 0px 0px 0px 2px inset;
  --elevation-2: rgba(0, 0, 0, 0.1) 0px 8px 16px 0px;
  --duration-1: 0.15s;
  --duration-2: 0.2s;
  --duration-3: 0.3s;
  --duration-4: 0.4s;
  --duration-5: 0.5s;
  --duration-6: 0.7s;
  --duration-7: 0.8s;
  --ease-1: cubic-bezier(0.455, 0.03, 0.515, 0.955);
  --ease-2: cubic-bezier(0.645, 0.045, 0.355, 1);
  --ease-3: cubic-bezier(0.165, 0.84, 0.44, 1);
  --ease-4: steps(1);
  --ease-5: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-6: steps(1, start);
  --ease-7: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-8: linear;
}
```
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: #000000;
  --color-text: #FFFFFF;
  --color-text-muted: #898989;
  --color-border: #E7E7E7;
  --color-action: #2F2F2F;
  --color-on-action: #FFFFFF;
  --color-positive: #1E4C41;
  --color-negative: #200603;
  --font-body: "Clarkson", "Figtree", sans-serif;
  --font-interface: "Clarkson Serif", "Source Serif 4", serif;
  --text-display-large: 64px;
  --text-display-large--line-height: 66.5601px;
  --text-display-large--letter-spacing: -0.06em;
  --text-display-medium: 56px;
  --text-display-medium--line-height: 60.48px;
  --text-display-medium--letter-spacing: -0.04em;
  --text-display-small: 40px;
  --text-display-small--line-height: 43.2px;
  --text-display-small--letter-spacing: -0.04em;
  --text-headline: 26px;
  --text-headline--line-height: 28.08px;
  --text-headline--letter-spacing: -0.02em;
  --text-title: 20px;
  --text-title--line-height: 24px;
  --text-title--letter-spacing: -0.01em;
  --text-body-large: 15px;
  --text-body-large--line-height: 21px;
  --text-body-large--letter-spacing: -0.001em;
  --text-body-small: 14px;
  --text-body-small--line-height: 14px;
  --text-label-large: 13px;
  --text-label-small: 12px;
  --text-label-small--line-height: 16.8px;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 8px;
  --radius-xl: 16px;
  --radius-3xl: 30px;
  --radius-full: 9999px;
  --shadow-e1: color(srgb 0 0 0 / 0.2) 0px 0px 0px 2px inset;
  --shadow-e2: rgba(0, 0, 0, 0.1) 0px 8px 16px 0px;
  --ease-1: cubic-bezier(0.455, 0.03, 0.515, 0.955);
  --ease-2: cubic-bezier(0.645, 0.045, 0.355, 1);
  --ease-3: cubic-bezier(0.165, 0.84, 0.44, 1);
  --ease-4: steps(1);
  --ease-5: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-6: steps(1, start);
  --ease-7: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-8: linear;
}
```
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)", "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)" },
  fontFamily: { "body": ["var(--font-body)"], "interface": ["var(--font-interface)"] },
  borderRadius: { "sm": "var(--radius-sm)", "md": "var(--radius-md)", "lg": "var(--radius-lg)", "xl": "var(--radius-xl)", "3xl": "var(--radius-3xl)", "full": "var(--radius-full)" },
  boxShadow: { "e1": "var(--elevation-1)", "e2": "var(--elevation-2)" },
}
```

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-2 { /* Inline 2 */
  background: transparent;
  color: var(--color-text);
  font-family: "sans-serif";
  font-size: 16px;
  font-weight: 400;
}
.link-3 { /* Inline 3 */
  background: transparent;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-label-small);
  font-weight: 400;
  line-height: 16.8px;
}
.button-2 { /* Secondary */
  background: #FFFFFF;
  border-radius: var(--radius-md);
  padding: 23px 28px 23px 28px;
  min-height: 60px;
  color: #000000;
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 14px;
}
.button-3 { /* Icon */
  background: #FFFFFF;
  border: 1px solid #E7E7E7;
  border-radius: var(--radius-3xl);
  min-height: 30px;
  color: #000000;
  font-family: "sans-serif";
  font-size: 16px;
  font-weight: 400;
}
```
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
- Dark interface on #000000. Keep that ground; do not add a light mode.
- The opening screen carries a large image or video beside 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 (#000000) and Text (#FFFFFF); use only those.
- #2F2F2F is the action colour. Fill the primary action with it and little else — at most one #2F2F2F-filled element per screen; other accents keep to the uses listed above.
- Type: Figtree (standing in for Clarkson) for body; Source Serif 4 (standing in for Clarkson Serif) for interface. Hierarchy comes from size and weight, not colour or decoration.
- Everything sits on a 4px grid.
- Corner radii are 3px, 4px, 8px, 16px, 30px, fully round (pill) — nothing else.
- Body text uses Clarkson at around 15px, weights 300, 400, 500, 700.
- Headings use Clarkson Serif; the largest heading is 72px.
- Primary buttons are #2F2F2F, 8px radius, weight 400.
- Cards use 3px corners.
- Corner radii in use: 8px, 3px, 30px, 100px, 4px.

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 — 590px tall, centred 64px heading (weight 300) set mid-band.
2. Statement — 412px tall, centred 15px heading (weight 400), image centred.
3. Statement — 373px tall, centred 64px heading (weight 300), on #000000.
4. Cards — 1091px tall, split 2 / 8 / 2, 40px gap, centred 40px heading (weight 400), image on the left, on #FFFFFF.
5. Text — 776px tall, a strip of 9 small items (logos, links or icons), left-aligned 40px heading (weight 400), image on the left, on #FFFFFF.
6. Split — 1097px tall, 2 equal columns, 40px gap, centred 40px heading (weight 400), image behind the content, on #FFFFFF.
7. Statement — 381px tall, centred 40px heading (weight 400), on #000000.
8. Statement — 306px tall, centred 40px heading (weight 400), on #000000.
9. Full-bleed image — 772px tall, centred 40px heading (weight 300) set mid-band, image behind the content, on #000000.
10. Text (×2) — 2 bands of 123px, left-aligned 40px heading (weight 400), on #000000.
11. Split — 123px tall, 2 equal columns, 40px gap, left-aligned 40px heading (weight 400), on #000000.
12. Full-bleed image — 852px tall, centred 56px heading (weight 300) set mid-band, image behind the content.
13. Footer — 727px tall, split 4 / 8, 40px gap, left-aligned 26px heading (weight 400), on #000000.
- Content runs 1127px wide with 157px side margins at 1440px; there is no narrower centred container.
- A 80px header stays fixed at the top, transparent over the first section.
- The hero is 590px (0.7 screens): centred 64px heading (weight 300) set mid-band.
- Column splits on a 12-column grid: halves (2×), 2/8/2, 4/8; gaps of 40px.
- Headings are centred (9 of 13 sections).
- Sections change background 5 times, between #000000, #FFFFFF: colour comes in full-width bands, not in boxes.
- A typical section is about 412px tall.

COPY SHAPE (MATCH THE LENGTH AND CASE; WRITE YOUR OWN WORDS)
- The main heading is 5 words long.
- Section headings are medium length: typically 6 words.
- Headings are in sentence case (only the first word capitalised).
- The page describes itself in about 25 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 880px wide, centred, with var(--space-4) (16px) side padding on small screens.
- The largest heading scales fluidly: font-size: clamp(26px, 4.4vw, 64px). 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 (21:1), Text muted on Background (6:1) and On action on Action (13.4:1).
- 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)
- Only the two shadows in the tokens, on the components that use them. (2 shadow values were 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: #000000, #FFFFFF, #2F2F2F, #898989, #E7E7E7, #1E4C41, #200603. 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: Figtree for body; Source Serif 4 for interface. No other typeface, and no Inter, Roboto or system UI font unless it is one of these. (The page is set in Clarkson and Clarkson Serif; the tokens carry what stands in for them.)
- Headings and large text never heavier than weight 400. Do not make headlines bold to add emphasis. (Every size from 24px up is set at weight 400 or lighter.)
- Large headlines tracked tight (letter-spacing -0.06em), not at the browser default. (The 64px headline is set at -0.06em.)
- 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, statement, cards, text, split, image, 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 squarespace.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.
- No text 24px or larger has a font-weight above 400.
- 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.
- 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.