# DESIGN.md: Booking.com-style design system

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

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 booking.com, measured from the live site: it should feel designed by the same team as booking.com — the same temperament, colour, type and density — for a different product. Never use booking.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.booking.com/index.hi.html — "www.booking.com".
- Page frame: a top navigation bar and a footer.
- Content is grouped in cards (10 on the page, up to 4 side by side). Keep cards for grouped content only, not for every section.
- It uses 112 images, 27 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: 73 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 #F5F5F5.
- #003B95 is an accent: 1.1% of the page, as small fills such as buttons and badges. Keep it to small areas.
- #FFB700 is an accent: 0.1% of the page, as small fills such as buttons and badges. Keep it to small areas.
- The largest type (48px Avenir Next) is bold (700).
- Open: text covers 9% of the page.
- Structure comes from thin grid lines, not from shadows or filled cards.
- Share of the painted page: #FFFFFF 86% (dominant, backgrounds); #F5F5F5 5.3% (supporting, backgrounds); #000000 3.6% (detail, backgrounds); #1A1A1A 2.8% (supporting, text); #003B95 1.1% (accent, backgrounds); #595959 0.8% (supporting, text); #FFB700 0.1% (accent, backgrounds); #006CE4 0.1% (accent, text). Keep accents at these proportions; do not promote them to fills.
- Hairline grid: 1px lines in #E7E7E7 run both across and down the page (24 across, 22 down), dividing it into cells instead of cards.
- Large images: Photographs, video or raster artwork cover about 62% of the page.
- Type as set (size, weight and tracking measured together; use these pairs): 48px weight 700; 24px weight 700; 20px weight 700; 16px weight 700; 14px weight 400; 12px 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:
- #FFFFFF — 86% · backgrounds (var(--color-background))
- #F5F5F5 — 5.3% · backgrounds (var(--color-f5f5f5))
- #000000 — 3.6% · backgrounds (var(--color-000000))
- #1A1A1A — 2.8% · text (var(--color-text))
- #003B95 — 1.1% · backgrounds (var(--color-003b95))
- #595959 — 0.8% · text (var(--color-text-muted))
- #FFB700 — 0.1% · backgrounds (var(--color-warning))
- #006CE4 — 0.1% · text (var(--color-link))
- #E7E7E7 — 0.1% · backgrounds, lines (var(--color-surface))
- #008234 — Positive (var(--color-positive))
- #D4111E — 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=Jost:wght@400;700&display=swap");
```
Font: booking.com uses Avenir Next (display) — its own licensed face, not available to download. This kit uses Jost for display, 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.
Keep every size, weight, line height and tracking exactly as listed whichever font renders.
```css
:root {
  --color-background: #FFFFFF; /* Background */
  --color-surface: #E7E7E7; /* Surface */
  --color-text: #1A1A1A; /* Text */
  --color-text-muted: #595959; /* Text muted */
  --color-border: #E7E7E7; /* Border */
  --color-action: #FFFFFF; /* Action */
  --color-on-action: #1A1A1A; /* On action */
  --color-link: #006CE4; /* Link */
  --color-positive: #008234; /* Positive */
  --color-negative: #D4111E; /* Negative */
  --color-warning: #FFB700; /* Warning */
  --color-f5f5f5: #F5F5F5; /* 5.3% of the page, as fills */
  --color-000000: #000000; /* 3.6% of the page, as fills */
  --color-003b95: #003B95; /* 1.1% of the page, as fills */
  --font-body: "BlinkMacSystemFont", sans-serif; /* BlinkMacSystemFont */
  --font-display: "Avenir Next", "Jost", sans-serif; /* Avenir Next on the site; Jost renders */
  --type-display: 48px; /* Display, weight 700 */
  --type-display-leading: 62px;
  --type-headline: 24px; /* Headline, weight 700 */
  --type-headline-leading: 32px;
  --type-title: 20px; /* Title, weight 700 */
  --type-title-leading: 28px;
  --type-body-large: 16px; /* Body Large, weight 700 */
  --type-body-large-leading: 24px;
  --type-body-small: 14px; /* Body Small, weight 400 */
  --type-body-small-leading: 20px;
  --type-label: 12px; /* Label, weight 400 */
  --type-label-leading: 18px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-9: 36px;
  --space-12: 48px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-xl: 16px;
  --radius-full: 9999px;
  --elevation-1: rgba(26, 26, 26, 0.16) 0px 2px 8px 0px;
  --duration-1: 0.12s;
  --duration-2: 0.24s;
  --ease-1: cubic-bezier(0.2, 0, 0.4, 0.8);
  --ease-2: cubic-bezier(0, 0, 0.4, 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: #FFFFFF;
  --color-surface: #E7E7E7;
  --color-text: #1A1A1A;
  --color-text-muted: #595959;
  --color-border: #E7E7E7;
  --color-action: #FFFFFF;
  --color-on-action: #1A1A1A;
  --color-link: #006CE4;
  --color-positive: #008234;
  --color-negative: #D4111E;
  --color-warning: #FFB700;
  --color-f5f5f5: #F5F5F5;
  --color-000000: #000000;
  --color-003b95: #003B95;
  --font-body: "BlinkMacSystemFont", sans-serif;
  --font-display: "Avenir Next", "Jost", sans-serif;
  --text-display: 48px;
  --text-display--line-height: 62px;
  --text-headline: 24px;
  --text-headline--line-height: 32px;
  --text-title: 20px;
  --text-title--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: 12px;
  --text-label--line-height: 18px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-xl: 16px;
  --radius-full: 9999px;
  --shadow-e1: rgba(26, 26, 26, 0.16) 0px 2px 8px 0px;
  --ease-1: cubic-bezier(0.2, 0, 0.4, 0.8);
  --ease-2: cubic-bezier(0, 0, 0.4, 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)", "action": "var(--color-action)", "on-action": "var(--color-on-action)", "link": "var(--color-link)", "positive": "var(--color-positive)", "negative": "var(--color-negative)", "warning": "var(--color-warning)" },
  fontFamily: { "body": ["var(--font-body)"], "display": ["var(--font-display)"] },
  borderRadius: { "sm": "var(--radius-sm)", "md": "var(--radius-md)", "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-display); margin: 0; }
a { color: var(--color-link); }
: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: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 400;
  line-height: 20px;
}
.card { /* Default */
  background: var(--color-f5f5f5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  min-height: 210px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 400;
  line-height: 20px;
}
.card-2 { /* Alternative 1 */
  background: var(--color-background);
  border-radius: var(--radius-xl);
  min-height: 320px;
  box-shadow: var(--elevation-1);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 400;
  line-height: 20px;
}
.card-3 { /* Alternative 2 */
  background: var(--color-warning);
  border-radius: var(--radius-md);
  padding: var(--space-1);
  min-height: 59px;
  box-shadow: var(--elevation-1);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 400;
  line-height: 20px;
}
.button { /* Secondary */
  background: var(--color-action);
  border-radius: 50%;
  padding: 4px 12px 4px 12px;
  min-height: 36px;
  box-shadow: var(--elevation-1);
  color: var(--color-on-action);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 20px;
}
.button-2 { /* Secondary 2 */
  background: var(--color-background);
  border-radius: var(--radius-sm);
  padding: 4px 12px 4px 12px;
  min-height: 36px;
  color: var(--color-link);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 20px;
}
.button-3 { /* Secondary 3 */
  background: var(--color-background);
  border-radius: var(--radius-sm);
  padding: 0px 8px 0px 8px;
  min-height: 34px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 400;
  line-height: 20px;
  /* recorded states: collapsed */
}
.input { /* Default */
  background: transparent;
  border-radius: var(--radius-sm);
  padding: 0px 8px 0px 8px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--type-body-small);
  font-weight: 500;
  line-height: 20px;
  /* recorded states: collapsed */
}
```
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.
- #FFFFFF is the action colour. Fill the primary action with it and little else — at most one #FFFFFF-filled element per screen; other accents keep to the uses listed above.
- Type: BlinkMacSystemFont for body; Jost (standing in for Avenir Next) for display. Hierarchy comes from size and weight, not colour or decoration.
- Everything sits on a 4px grid.
- Corner radii are 4px, 8px, 16px, fully round (pill) — nothing else.
- Body text uses BlinkMacSystemFont at around 16px, weights 400, 500, 600, 700.
- Headings use Avenir Next; the largest heading is 48px.
- Primary buttons are #FFFFFF, 4px radius, weight 500.
- Cards use 8px corners with a soft shadow.
- Corner radii in use: 8px, 4px, 9999px (pill), 16px.

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 — 518px tall, left-aligned 48px heading (weight 700), image behind the content.
2. Cards — 258px tall, 4 equal columns, 16px gap, left-aligned 24px heading (weight 700).
3. Split — 233px tall, split 11 / 1, left-aligned 24px heading (weight 700), image on the right.
4. Split — 636px tall, 2 equal columns, 16px gap, left-aligned 24px heading (weight 700), image on the left.
5. Text — 296px tall, a strip of 24 small items (logos, links or icons), left-aligned 24px heading (weight 700), image on the left.
6. Text — 271px tall, a strip of 10 small items (logos, links or icons), left-aligned 24px heading (weight 700), image on the left.
7. Text — 434px tall, a strip of 15 small items (logos, links or icons), left-aligned 24px heading (weight 700), image on the left.
8. Text — 482px tall, a strip of 12 small items (logos, links or icons), left-aligned 24px heading (weight 700), image on the left.
9. Text — 339px tall, a strip of 9 small items (logos, links or icons), left-aligned 24px heading (weight 700), image on the left.
10. Grid — 366px tall, 7 items in 6 columns with 16px gaps, left-aligned 24px heading (weight 700), image on the left.
11. Split — 178px tall, split 11 / 1, 8px gap, left-aligned 24px heading (weight 700), image on the right.
12. Text — 314px tall, left-aligned 24px heading (weight 700).
13. Footer — 553px tall, split 2 / 3 / 2 / 2 / 3, 70px gap, left-aligned 16px heading (weight 500) set low in the band, on #F5F5F5.
- Content sits in a 1140px container, 166px from the edge at 1440px wide.
- A 124px header scrolls away.
- The hero is 518px (0.6 screens): left-aligned 48px heading (weight 700), image behind the content.
- Column splits on a 12-column grid: 11/1 (2×), quarters, halves, sixths; gaps of 16px.
- Headings align left (13 of 13 sections); centre only the occasional statement.
- Sections share one background; they are separated by space and lines, not colour bands.
- A typical section is about 314px tall.

COPY SHAPE (MATCH THE LENGTH AND CASE; WRITE YOUR OWN WORDS)
- The main heading is 3 words long.
- Section headings are medium length: typically 5 words.
- Heading case varies.
- The page describes itself in about 43 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 1140px 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 (17.4:1), Text muted on Background (7:1), Link on Background (4.9:1), Positive on Background (4.9:1), Negative on Background (5.4:1), Text on Surface (14.1:1), Text muted on Surface (5.7:1) and On action on Action (17.4:1).
- Only for text 24px and up, or 18.66px bold: Link on Surface (4:1), Positive on Surface (4:1) and Negative on Surface (4.4:1).
- 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 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, #F5F5F5, #000000, #1A1A1A, #003B95, #595959, #FFB700, #006CE4, #E7E7E7, #008234, #D4111E. 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.)
- #003B95 only as small fills (buttons, badges) — never a section background or a large panel. (It covers 1.1% of the page.)
- #FFB700 only as small fills (buttons, badges) — never a section background or a large panel. (It covers 0.1% of the page.)
- Only the fonts in the tokens: BlinkMacSystemFont for body; Jost for display. No other typeface, and no Inter, Roboto or system UI font unless it is one of these. (The page is set in BlinkMacSystemFont and Avenir Next; 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 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.)
- 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, cards, split, text, 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 booking.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.
- #003B95 covers about 1.1% of the page or less, as on the original.
- #FFB700 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.
- Content sits in a 1140px container with 166px 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.