anthropic.com

DESIGN.md

Narrative design system document — paste directly into Claude Code, Cursor, or Bolt.

---
version: alpha
name: anthropic.com
description: "Light product system built on #faf9f5 with #141413 as the primary CTA accent. Type anchored in Anthropic Serif at 68.3429px / weight 400. Extracted automatically from https://anthropic.com/ — rendered styles via getComputedStyle() + CSS custom properties (token-only values may not be painted)."
narrative: |
  anthropic.com is built on a warm, off-white canvas (rgb(250, 249, 245)).
  The system uses rgb(20, 20, 19) as a near-neutral accent (low saturation).
  Sharp 0px corners on CTAs — architectural restraint, engineering precision alongside editorial serif type (Anthropic Serif) — voice of authority.
  Anthropic Serif is paired with Anthropic Sans for secondary roles.
  A restrained elevation system (1 distinct shadow) — shadows reserved for the few elements that must lift off the page.
  Motion is a first-class concern — 5 keyframe animations plus transition-driven interactions.

colors:
  background: "#faf9f5"
  surface-1: "#f0eee6"
  surface-2: "#f9f9f7"
  ink: "#141413"
  ink-muted: "rgba(20, 20, 19, 0.65)"
  ink-subtle: "#141413"
  primary: "#141413"
  on-primary: "#ffffff"
  primary-hover: "#3d3d3a"
  hairline: "rgba(20, 20, 19, 0.1)"

typography:
  display-xl:
    fontFamily: "Anthropic Serif, Georgia, 'Times New Roman', serif"
    fontSize: 68.3429px
    fontWeight: 400
    lineHeight: 1.1
    letterSpacing: 0
  display-md:
    fontFamily: "Anthropic Sans, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif"
    fontSize: 24px
    fontWeight: 600
    lineHeight: 1.3
    letterSpacing: 0
  body:
    fontFamily: "Anthropic Serif, Georgia, 'Times New Roman', serif"
    fontSize: 20px
    fontWeight: 400
    lineHeight: 1.4
    letterSpacing: 0
  body-sm:
    fontFamily: "Anthropic Serif, Georgia, 'Times New Roman', serif"
    fontSize: 18px
    fontWeight: 600
    lineHeight: 1.4
    letterSpacing: 0
  caption:
    fontFamily: "Anthropic Sans, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif"
    fontSize: 16px
    fontWeight: 500
    lineHeight: 1.4
    letterSpacing: 0
  button:
    fontFamily: "Anthropic Sans, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif"
    fontSize: 16px
    fontWeight: 400
    lineHeight: 1
    letterSpacing: -0.08px

rounded:
  none: 0px
  xs: 8px
  sm: 16px
  md: 24px
  lg: 1600px
  xl: 1608px
  pill: 1600px

spacing:
  xxs: 2px
  xs: 4px
  sm: 8px
  md: 12px
  lg: 24px
  xl: 32px
  xxl: 64px

components:
  button-ghost:
    backgroundColor: "transparent"
    textColor: "{colors.hairline}"
    typography: "{typography.body}"
    rounded: "{rounded.none}"
    padding: 22.4px 12px
  button-ghost-2:
    backgroundColor: "transparent"
    textColor: "{colors.hairline}"
    typography: "{typography.body}"
    rounded: "{rounded.none}"
    padding: 0px 0px 0px 12px
  button-dark--solid:
    backgroundColor: "{colors.hairline}"
    textColor: "{colors.background}"
    typography: "{typography.button}"
    rounded: "{rounded.xs}"
    padding: 8px 16px

extracted_at: "2026-06-11T06:01:23.750Z"
completeness: 68
scoreVersion: "v2"

---

# Design System — anthropic.com
> Extracted automatically by Prism from https://anthropic.com
> Date: 2026-06-11
> Viewport: Desktop 1440x900 + Mobile 390x844
> Values are extracted, not hand-written: rendered styles via getComputedStyle() + colors declared in CSS custom properties (token-only values are marked `(token)` and may not be painted).


## 0. Design DNA

**Density**: moderate  |  **Motion**: subtle  |  **Weight**: heavy  |  **Aesthetic**: editorial-minimal

| Dimension | Value | Signal |
|---|---|---|
| Canvas | neutral | `#faf9f5` |
| Type posture | serif-led (Anthropic Serif) | "Announcing Fable 5" |
| Color assertion | dual-accent | #141413 |
| Whitespace | moderate | section rhythm 48px |
| Interaction | subtle | 5 keyframes, 20 transitions |
| Radius language | 8px-rounded | from token scale |

**Prism fingerprint**: `neutral-canvas · serif-display · dual-accent · 8px-rounded · subtle-motion`

> **🤖 TL;DR for AI agents** (read this first — saves you scanning the full doc):
>
> - **Canvas**: `rgb(250, 249, 245)` is the page background. Every component composits against this.
> - **Accent**: `rgb(20, 20, 19)` for primary CTAs ONLY. Never decorative.
> - **Body type**: 20px (token: `typography.body`). Default for ALL text not in a heading role.
> - **Section rhythm**: 48px between major bands. Card padding: 24px.
> - **Default radius**: 16px on buttons/inputs. Pills (`9999px`) only for icon-buttons or status chips.
>
> **Before generating UI**: import this DESIGN.md, scan §2 (Color Palette) + §4 (Components) + §10 (Agent Guide). Skip §11–12 unless extending.

## 1. Visual Theme & Atmosphere

anthropic.com's canvas is a warm, intentionally-tinted surface (`#faf9f5`) — a refusal of the default white that immediately signals editorial intent. This isn't sterility, it's an invitation to read. 

Typography is anchored in **Anthropic Serif**. Headlines use weight 700 for confident, assertive presence — the brand wants to be heard. 

Body text reads in Near-Black (`#141413`) — softened from pure black, a small but deliberate detail that lowers reading friction. **Near-Black** (`#141413`) provides interactive distinction without visual aggression. Elevation comes from a small, deliberate set of shadows (1 distinct), each a multi-layer stack — several blurred layers at varying offsets — used sparingly rather than across the whole UI. 
Border radius varies from pill-shaped (fully rounded) to moderately rounded elements, creating visual rhythm. Motion design uses smooth easing curves for polished state transitions. The site uses a variable font with OPSZ axes, enabling precise weight/width control across the type hierarchy. 

**Key Characteristics:**
- Background: Off-White (`#faf9f5`)
- Primary typeface: Jetbrains Mono
- Primary text: Near-Black (`#141413`)
- Accent: Near-Black (`#141413`)
- Display: 60.8653px weight 700
- Shadow system: 1 distinct elevation levels
- Custom fonts loaded: Jetbrains Mono, Anthropic Sans, Anthropic Serif, Anthropic Mono

## 2. Color Palette & Roles

### Background & Surface
- **Off-White** (`#faf9f5`): Page background (primary)
- **Whitesmoke** (`#f0eee6`): Surface / elevated background
- **Off-White** (`#f9f9f7`): Surface / elevated background
- **Vibrant Yellow** (`#f5e3c7`): Surface / elevated background
- **#e3dacc** (`#e3dacc`): Surface / elevated background

### Text & Content
- **Near-Black** (`#141413`): Primary body text
- **Pure Black** (`#000000`): Secondary text
- **Near-Black** (`#181818`): Secondary text
- **Near-Black** (`#101010`): Secondary text

### Accent & Interactive
- **Terracotta** (`#c6613f`): Interactive / accent

### Full Extracted Palette
**12 colors rendered on the page** + **13** more declared in design tokens (CSS custom properties — not necessarily painted). (10 categorized above + 15 additional below.)
Rendered values are read via `getComputedStyle()`; token values come from CSS variable declarations. Third-party logo colors are filtered out.

- `#87867f` — Slate Grey
- `#b0aea5` — Cool Gray
- `#d97757` — Warm Terracotta *(token)*
- `#3d3d3a` — Charcoal *(token)*
- `#5e5d59` — Slate Grey *(token)*
- `#c46686` — #c46686 *(token)*
- `#bcd1ca` — Silver *(token)*
- `#ebcece` — Pink *(token)*
- `#cbcadb` — Silver *(token)*
- `#788c5d` — Stone *(token)*
- `#d4a27f` — #d4a27f *(token)*
- `#e8e6dc` — Beige *(token)*
- `#d1cfc5` — Silver *(token)*
- `#ebdbbc` — #ebdbbc *(token)*
- `#6a9bcc` — Cornflower Blue *(token)*

### CSS Custom Properties (Design Tokens)

**Spacing Token**
- `--_spacing---space--11`: `clamp(3.5rem, 2.7346938775510203rem + 3.2653061224489797vw, 6rem)`
- `--_spacing---section-space--extra-small`: `clamp(1.75rem, 1.6734693877551021rem + 0.326530612244898vw, 2rem)`
- `--_typography---letter-spacing--0em`: `0em`
- `--_spacing---section-space--medium`: `clamp(3.5rem, 2.7346938775510203rem + 3.2653061224489797vw, 6rem)`

**Font Weight Token**
- `--_text-style---font-weight`: `400`

**Font Size Token**
- `--_text-style---font-size`: `1.25rem`
- `---font-size--paragraph-m`: `clamp(1.125rem, 1.086734693877551rem + 0.163265306122449vw, 1.25rem)`
- `--_typography---font-size--paragraph-xs`: `1rem`
- `---font-size--paragraph-s`: `clamp(1rem, 0.9617346938775511rem + 0.163265306122449vw, 1.125rem)`

**Border Radius Token**
- `--radius--main`: `.5rem`
- `--radius--large`: `1rem`
- `--radius--round`: `100vw`
- `--radius--small`: `.25rem`

**Motion Token**
- `--nav--menu-open-duration`: `400ms`
- `--nav--dropdown-duration`: `200ms`
- `--nav--dropdown-open-duration`: `200ms`

**Font Family Token**
- `--_text-style---font-family`: `"Anthropic Serif",Georgia,sans-serif`

**Other tokens**
- `--_color-theme---border`: `#1414131a`
- `--_color-theme---button-primary--border-hover`: `#3d3d3a`
- `--_color-theme---button-primary--text`: `#faf9f5`
- `--_color-theme---button-tertiary--border`: `#1414131a`
- `--_button-style---text`: `#faf9f5`
- `--align--text-right`: `right`
- `--_color-theme---button-primary--text-hover`: `#faf9f5`
- `--_typography---font--display-sans`: `"Anthropic Sans",Arial,sans-serif`

## 3. Typography Rules

### Font Families
- **Primary**: `Anthropic Serif`
- **Secondary**: `Anthropic Sans`
- **Font 3**: `webflow-icons`
- **Font 4**: `Jetbrains Mono`
- **Font 5**: `Anthropic Mono`

### Custom Fonts Loaded
- **webflow-icons** weight 400 (normal)
- **Jetbrains Mono** weight 400 (normal)
- **Anthropic Sans** weight 300 800 (normal)
- **Anthropic Serif** weight 300 800 (normal)
- **Anthropic Mono** weight 300 800 (normal)

### Typography Hierarchy

| Role | Font | Size | Weight | Line Height | Letter Spacing | Notes |
|------|------|------|--------|-------------|----------------|-------|
| Display Hero | Anthropic Serif | 68.3429px | 400 | 1.1 | normal | Main headline (h2) |
| Sub-heading | Anthropic Sans | 24px | 600 | 1.3 | normal | Third-level heading (h3) |
| Body | Anthropic Serif | 20px | 400 | 1.4 | normal | Standard reading text |
| Link Large | Anthropic Serif | 18px | 600 | 1.4 | normal | Link (18px) — Decoration: 1px |
| Button Large | Anthropic Sans | 16px | 400 | 1 | -0.08px | Button label (16px) |
| Link Large | Anthropic Serif | 16px | 400 | 1.4 | normal | Link (16px) — Decoration: 1px |
| Caption / Badge | Anthropic Sans | 16px | 500 | 1.4 | normal | small text (16px) |
| Button | Anthropic Sans | 15px | 400 | 1 | -0.08px | Button label (15px) |

### Full Font Size Scale

Sizes detected in the design (descending): `68.34px`, `60.87px`, `24px`, `20px`, `18px`, `16px`, `15px`, `14px`, `12px`

> 3 size(s) detected outside the sampled hierarchy (60.8653px, 14px, 12px). These appear on elements not in the sampled set — likely additional display sizes, marketing-section overrides, or third-party-widget styles.

### OpenType & Variable Font Features

**Variable font axes:**
- OPSZ axis

## 4. Component Stylings

### Buttons

**Ghost**
- Background: `transparent`
- Text: `#141413` `{colors.hairline}`
- Padding: 22.4px 12px
- Radius: 0px
- Font: 20px weight 400
- Use: Subtle action, toolbar, nav button

**Ghost**
- Background: `transparent`
- Text: `#141413` `{colors.hairline}`
- Padding: 0px 0px 0px 12px
- Radius: 0px
- Font: 20px weight 400
- Use: Subtle action, toolbar, nav button

**Dark / Solid**
- Background: `#141413` `{colors.hairline}`
- Text: `#faf9f5` `{colors.background}`
- Padding: 8px 16px
- Radius: 8px 0px 0px 8px
- Border: 1px solid rgb(20, 20, 19)
- Font: 16px weight 400
- Use: Solid dark CTA

**Dark / Solid**
- Background: `#141413` `{colors.hairline}`
- Text: `#faf9f5` `{colors.background}`
- Padding: 8px 16px
- Radius: 8px
- Border: 1px solid rgb(20, 20, 19)
- Font: 16px weight 400
- Use: Solid dark CTA

**Pill**
- Background: `transparent`
- Text: `#141413` `{colors.hairline}`
- Padding: 0px
- Radius: 8px
- Font: 16px weight 400
- Use: Status pills, tags, chips

**Light / Invert**
- Background: `#faf9f5` `{colors.background}`
- Text: `#141413` `{colors.hairline}`
- Padding: 12px 31.4776px
- Radius: 0px 0px 8px 8px
- Font: 18px weight 600
- Use: Bright CTA on dark sections


## 4b. Component Behaviors (State Matrix)

### Interaction State Narrative


*State transitions extracted via Playwright simulation — exact values in the YAML matrix below.*

```yaml
component-behaviors:
  button:
    default:
      bg: "rgba(0, 0, 0, 0)"
      fg: "rgb(20, 20, 19)"
  link:
    default:
      bg: "rgb(250, 249, 245)"
      fg: "rgb(20, 20, 19)"
  navLink:
    default:
      bg: "rgba(0, 0, 0, 0)"
      fg: "rgb(20, 20, 19)"
    hover:
      bg: "transparent"
      fg: "inherit"
  badge:
    default:
      bg: "rgba(0, 0, 0, 0)"
      fg: "rgb(20, 20, 19)"
  footerLink:
    default:
      bg: "rgba(0, 0, 0, 0)"
      fg: "rgb(176, 174, 165)"
    hover:
      bg: "transparent"
      fg: "inherit"
```

**Agent usage**: Validate generated components against this matrix. If your output's `:hover` state changes properties not listed here, you are off-brand.


## 4c. Component Vocabulary (Closed System)

*This brand uses ONLY the following component vocabulary. Introducing new variants without justification breaks the system's tonal coherence.*

### Buttons
- **4 shape(s)** in this system: `Ghost`, `Dark / Solid`, `Pill`, `Light / Invert`
- **DO NOT introduce new buttons variants** without justification

## 5. Layout Principles

### Layout Type
**top-nav + content**

### Grid
Flexbox column

### Max Width
min(89.5rem, 100vw)

### Spacing System
Compact spacing — information density prioritized

| Token | Value |
|-------|-------|
| xxs | 2px |
| xs | 4px |
| sm | 8px |
| md | 12px |
| base | 16px |
| lg | 24px |
| xl | 32px |
| 2xl | 48px |
| 3xl | 64px |

### Border Radius Scale
| Name | Value | Use |
|------|-------|-----|
| None | 0px | No rounding |
| Xs | 8px | Tiny corners (badges, micro elements) |
| Sm | 16px | Buttons, inputs, small elements |
| Md | 24px | Cards, containers |
| Lg | 1600px | Large rounded elements, pill segments |
| Xl | 1608px | Category strips, featured containers |
| Full | 1600px | Pills, avatars, circular elements |

### Shape Language

| Component | Border Radius |
|-----------|---------------|
| Buttons | `0px` |
| Page Body | `0px` |
| Navigation | `0px` |

**Shape Personality**: Sharp & Angular — No rounding. Precise, editorial, enterprise feel.

**Full Radius Spectrum**: 0px, 8px, 16px, 24px, full/pill (from `allBorderRadii` scan)


## 5b. Spacing Rhythm Names

**Measured section padding**: bands use ~76px internal vertical padding (up to 91px) — **generous**. (Distinct from the gap *between* sections above.) Reproduce this generous vertical breathing room; cramped spacing is the #1 tell of a cheap clone.

*Named spacing tokens with explicit use cases. Use these names in YOUR code instead of raw pixels for consistency.*

| Name | Value | Use case |
|------|-------|----------|
| **hero** | `64px` | Top/bottom of full-bleed hero sections |
| **section** | `32px` | Between major bands (color change, content shift) |
| **subsection** | `24px` | Within a section, between content groups |
| **card** | `12px` | Card padding, list-item spacing |
| **compact** | `8px` | Form fields, tight clusters, badge padding |
| **micro** | `4px` | Icon-text gap, tag inner padding |

**Agent rule**: NEVER hardcode raw pixel values for spacing in generated UI. Always reference these named tokens (`spacing-rhythm.section`, etc.).

## 5c. Widget & Structure Library

Structural patterns extracted from the page DOM — these are the **blueprints** an agent should follow to reproduce the page architecture (not just CSS values).

**4/8 structural patterns detected.**

### Hero Pattern

- **Composition:** left-aligned — 
- **Viewport coverage:** 179px tall (not full-viewport)
- **Heading:** "AI research and products that put safety at the frontierAI research and products that put safety at " — 61px left-aligned
- **Subheading:** "AI will have a vast impact on the world. Anthropic is a public benefit corporation dedicated to securing its benefits and mitigating its risks."
- **CTAs:** none detected in hero (unusual — agent should verify)
- **Clone instruction:** Reproduce the **left-aligned** layout. Use the heading font-size token at the documented size. No imagery needed for hero — text-driven.

### Navigation Pattern

- **Position:** static (scrolls with page)
- **Layout:** unknown — Layout not classified
- **Height:** 68px
- **Logo:** ✓ present
- **Nav links:** 4 primary items
- **CTAs in nav:** 0 (no buttons — links only)
- **Clone instruction:** Build a static unknown navigation. Link-only — no button styling needed.

### Card Grid Pattern

- **Card count:** 4 cards detected
- **Columns (desktop):** 7-up grid
- **Card dimensions:** 215×714px (aspect 0.3:1)
- **Gap:** 31px between cards
- **Content:** ✗ no image
- **Clone instruction:** Build a 7-column grid (desktop) with cards at ~0.3:1 aspect ratio. Text/icon-only cards (no photography).

### Footer Pattern

- **Columns:** 2
- **Links:** 83 total
- **Height:** 865px
- **Includes:** ✗ no newsletter | ✓ social icons |  ✓ copyright
- **Clone instruction:** Build a 2-column footer with ~42 links per column, social media links, and a copyright line.

## 6. Depth & Elevation

| Level | Treatment | Use |
|-------|-----------|-----|
| Flat (Level 0) | No shadow | Page background, content blocks |
| Layered (Level 1) | <br>`rgba(0, 0, 0, 0.01) 0px 2px 2px 0px`,<br>`rgba(0, 0, 0, 0.02) 0px 4px 4px 0px`,<br>`rgba(0, 0, 0, 0.04) 0px 16px 24px 0px` | Cards, elevated surfaces |

**Shadow Philosophy**: Multi-layered shadow system creating natural, atmospheric depth. Each shadow level combines multiple layers for realistic elevation.

## 7. Motion & Interaction

### Dominant Easing Curves

| Curve | Semantic Name |
|-------|---------------|
| `cubic-bezier(0.16,1,0.3,1)` | Ease Out — Decelerating |
| `cubic-bezier(0.77,0,0.175,1)` | Quart In-Out — Precise Symmetric |

### Duration Scale

| CSS Variable | Value | Tier |
|--------------|-------|------|
| `--nav--menu-open-duration` | `400ms` | Slow |
| `--nav--dropdown-duration` | `200ms` | Normal |
| `--nav--dropdown-open-duration` | `200ms` | Normal |
| `--nav--menu-close-duration` | `400ms` | Slow |

### Copy-Paste Transition Snippets

**Transform**
```css
transition: transform 0.2s, color 0.2s;
```

**All Props**
```css
transition: text-decoration-color 0.2s;
```

**Transform**
```css
transition: transform 0.2s;
```

**Opacity**
```css
transition: opacity 0.4s cubic-bezier(0.77, 0, 0.175, 1);
```

### Keyframe Animation Catalog

| Animation Name | Type | Animated Props | Use Hint |
|----------------|------|----------------|----------|
| `spin` | Rotate / Spin | transform | Loading indicator |
| `marquee` | Slide | transform | UI transition |
| `fadein` | Fade | opacity | Element entrance |
| `menuOpen` | Custom | clip-path | UI transition |
| `menuClose` | Custom | clip-path | UI transition |

### Motion Fingerprint

- **Speed Character**: Deliberate & Calm (median duration: `336ms`)
- **Dominant Easing**: custom cubic-bezier curves
- **Animation Library**: 5 unique animations (5 total including variants)

> This design moves with deliberate & calm timing using custom cubic-bezier curves, creating a UI that feels calm and controlled.

## 8. Do's and Don'ts

### Do
- Use Off-White (`#faf9f5`) as the page background — it's intentionally not pure white
- Use Near-Black (`#141413`) for text — not pure black, it's warmer and more readable
- Use Anthropic Serif as the primary typeface — it defines the brand personality
- Use the extracted shadow patterns for elevation — they are tuned to match the brand palette
- Use full-pill radius (9999px) only for specific elements (avatars, pills, toggles)
- Use Near-Black (`#141413`) as the primary accent — it's the brand's signature interactive color
- Use 8px 0px 0px 8px border-radius on buttons — the standard corner rounding for interactive elements
- Maintain nav height at 68px — consistent vertical space for the navigation bar
- Respect the 4px–32px spacing range — the design uses a wide scale for visual breathing room
- Use a 7-column grid on desktop — density matters for this content type

### Don't
- Don't use pure white (`#ffffff`) as a page background — the warm tone is part of the brand identity
- Don't use pure black (`#000000`) for text — the near-black adds warmth
- Don't substitute with generic sans-serif or serif — the custom font carries the brand
- Don't invent new shadow values — use only the extracted shadow levels
- Don't apply pill radius on rectangular buttons or cards — it's reserved for specific interactive elements
- Don't introduce additional saturated accent colors — the palette is intentionally controlled
- Don't collapse or hide the nav on scroll without an explicit scroll-triggered animation — the design uses fixed nav presence
- Don't make the nav sticky — this design lets it scroll away to maximize content focus
- Don't put a CTA button in the nav — this design uses links only at the top


## 7b. Enforceable Brand Rules

*Structured Do/Don't with reasoning and validation tests. Agents can programmatically verify generated UI.*

```yaml
rules:
  - id: brand-canvas-001
    type: do
    rule: "Always use the page background `rgb(250, 249, 245)` as the base canvas"
    why: "Every component is designed to composit against this exact tone"
    test: "document.body.style.backgroundColor === 'rgb(250, 249, 245)'"
  - id: brand-accent-001
    type: do
    rule: "Reserve `rgb(20, 20, 19)` for primary CTAs and brand-mark signals only"
    why: "Single chromatic assertion device — overuse dilutes meaning"
    test: "querySelectorAll('[style*=\"rgb(20, 20, 19)\"]').length <= 3 per fold"
```

## 9. Responsive Behavior

### Breakpoints
| Name | Width | Key Changes |
|------|-------|-------------|
| Mobile | 479px | Single column, compact spacing |
| Mobile Large | 767px | Expanded mobile layout |
| Tablet | 991px | Multi-column grids begin |

### Token Diff — Desktop vs Mobile

| Element | Property | Desktop | Mobile |
|---------|----------|---------|--------|
| heading | font-size | `60.8653px` | `40.2939px` |
| heading | line-height | `66.9518px` | `44.3233px` |
| nav | height | `68px` | `auto` |
| button | width | `139.594px` | `100%` |

### Collapsing Strategy
- Headlines: 60.8653px → 40.2939px on mobile
- Navigation: horizontal links → hamburger menu on mobile
- Cards: multi-column → stacked vertical on mobile
- Footer: multi-column → stacked single column on mobile

### Touch Targets
- Buttons: 22.4px 12px padding
- Navigation: adequate spacing between items
- Interactive elements: minimum 44px touch target recommended

### Collapsing Narrative

How the structural patterns adapt from desktop to mobile (extracted from both viewport extractions):

- **Card grid: 7-up → 1-up** — cards stack as viewport narrows, becoming a vertical list on mobile.


## 7c. Visual Effects & Dynamic Behavior

*The live/dynamic layer beyond static CSS — reproduce these, not flat substitutes. This is often what separates a faithful clone from a wireframe.*

- **Clip-path shapes** — 8 non-rectangular cut(s).

> **Motion fingerprint**: non-rectangular shapes (10)

## 9b. Visual Tone & Photography

**Tone:** No imagery

No detectable photographic content. The site composes entirely with typography, color blocks, and minimal vector graphics. Clone strategy: lean on type hierarchy + layout rhythm rather than visual media.

**Canonical Brand Image (OG):**
- https://cdn.prod.website-files.com/67ce28cfec624e2b733f8a52/68309ab48369f7ad9b4a40e1_open-graph.jpg
  *This is the image shown when the site is shared on social media — represents the brand visual essence.*

**Media Format Mix:**
- *No detectable images.*

**Imagery Guidance for clones:**
- Don't add stock imagery just to "fill space" — this site's clarity comes from typographic restraint.
- Use generous whitespace, strong type hierarchy, and color blocks for visual rhythm.

## 10. Agent Prompt Guide

### Quick Reference
- Background: Off-White (`#faf9f5`)
- Primary text: Near-Black (`#141413`)
- Accent: Near-Black (`#141413`)
- Border: Translucent Jet Black (10%) (`rgba(20, 20, 19, 0.1)`)
- Font: Anthropic Serif
- Body: 20px weight 400

### Example Component Prompts
- "Create a hero section on Off-White background (#faf9f5). Headline at 60.8653px Anthropic Serif weight 700, line-height 1.1, color #141413."
- "Create the primary CTA button: `#141413` background, `#141413` text, 1600px border-radius, 22.4px 12px padding, 700 weight, Anthropic Serif font."
- "Build navigation: static on `#faf9f5`. Anthropic Serif 20px weight 400 for links."

### Iteration Guide
1. **Canvas**: Set the light canvas to Off-White (`#faf9f5`) — every component is composited against this exact base.
2. **Typography**: All type in Anthropic Serif, weight range 400–700. Never exceed 700 — heavier weights break the brand's tonal restraint.
3. **Accent**: Near-Black (`#141413`) is the sole interactive color. On hover → Terracotta (`#c6613f`). Use CSS transitions, not opacity/brightness filters.
4. **Motion**: All transitions use `cubic-bezier(0.77,0,0.175,1)`. Timing: 200ms for micro-interactions, 400ms for layout changes. Never use linear for UI transitions — preserve the brand's easing personality.
5. **Shape**: CTAs at `0px`. Apply border-radius from the extracted scale only — don't invent intermediate values.
6. **Spacing**: Use the `--ca-space-*` token scale (4px–32px). All padding, margin, and gap values are multiples from this scale — no magic numbers.
7. **Tokens**: Import from §11 CSS Export (`--ca-*` vars). Never hardcode hex values — always reference a token so theming remains consistent.

## 11. CSS Design Tokens Raw Export

*Copy-paste ready `:root {}` block — all values extracted directly from the live site.*

```css
/* Colors */
:root {
  --ca-background: #faf9f5;
  --ca-surface-1: #f0eee6;
  --ca-surface-2: #f9f9f7;
  --ca-hairline: #141413;
  --ca-on-primary: #ffffff;
  --ca-primary-hover: #3d3d3a;
}

/* Typography */
:root {
  --ca-font-primary: "Anthropic Serif", system-ui, sans-serif;
  --ca-text-display: 68.3429px;
  --ca-text-body: 20px;
  --ca-text-small: 18px;
  --ca-text-caption: 16px;
  --ca-text-button: 16px;
}

/* Spacing & Radius */
:root {
  --ca-space-xxs: 2px;
  --ca-space-xs: 4px;
  --ca-space-sm: 8px;
  --ca-space-md: 12px;
  --ca-space-base: 16px;
  --ca-space-lg: 24px;
  --ca-space-xl: 32px;
  --ca-space-2xl: 48px;
  --ca-space-3xl: 64px;
  --ca-radius-none: 0px;
  --ca-radius-xs: 8px;
  --ca-radius-sm: 16px;
  --ca-radius-md: 24px;
  --ca-radius-lg: 1600px;
  --ca-radius-xl: 1608px;
  --ca-radius-full: 1600px;
}
```


## 13. Page Structure Skeleton

*The actual layout the source site uses. Reproduce these sections in order to match the site structure.*

```yaml
page-skeleton:
  - section: hero
    tag: main
    classes: ["page_wrap", "u-bg-ivory-medium"]
    height: 3351px
    width: full-bleed
    layout: flex-column justify=normal
    children: 7
    bg: "rgb(240, 238, 230)"
  - section: header
    tag: header
    classes: ["hero_wrap"]
    height: 390px
    width: full-bleed
    layout: flex-column justify=normal
    children: 3
  - section: feature-section
    tag: div
    height: 179px
    width: 1285px
    layout: block
    children: 1
  - section: feature-section
    tag: div
    classes: ["home_hero_grid", "u-grid-tablet"]
    height: 179px
    width: 1285px
    layout: grid: 12-col gap=31.4776px
    children: 2
  - section: unknown
    tag: div
    classes: ["home_hero_bump"]
    height: 123px
    width: 517px
    layout: block
    children: 1
    padding: "0px 0px 5px"
  - section: hero
    tag: section
    height: 946px
    width: full-bleed
    layout: flex-column justify=center
    children: 3
  - section: feature-section
    tag: div
    classes: ["is-fable-marmot"]
    height: 824px
    width: 1285px
    layout: flex-row justify=space-between
    children: 2
    vertical-padding: ~91px (generous)
    padding: "90.7755px 0px"
  - section: feature-section
    tag: div
    classes: ["g_section_wrap"]
    height: 623px
    width: full-bleed
    layout: flex-column justify=center
    children: 2
  - section: feature-section
    tag: div
    classes: ["u-radius-medium"]
    height: 532px
    width: 1285px
    layout: block
    children: 2
  - section: feature-section
    tag: section
    classes: ["g_section_wrap"]
    height: 458px
    width: full-bleed
    layout: flex-column justify=center
    children: 3
  - section: feature-section
    tag: div
    height: 368px
    width: 1285px
    layout: block
    children: 2
  - section: footer
    tag: footer
    classes: ["footer_wrap", "u-theme-dark"]
    height: 865px
    width: full-bleed
    layout: block
    children: 3
    bg: "rgb(20, 20, 19)"
    tone: dark
    vertical-padding: ~76px (generous)
  - section: footer
    tag: div
    height: 865px
    width: 1285px
    layout: block
    children: 1
    vertical-padding: ~76px (generous)
    padding: "75.8204px 0px"
  - section: navigation
    tag: nav
    classes: ["footer_grid"]
    height: 714px
    width: 1285px
    layout: grid: 12-col gap=31.4776px
    children: 3
  - section: footer
    tag: section
    classes: ["footer_group_wrap"]
    height: 714px
    width: 215px
    layout: flex-column justify=normal
    children: 2
  - section: footer
    tag: section
    classes: ["footer_group_wrap"]
    height: 714px
    width: 215px
    layout: flex-column justify=normal
    children: 2
  - section: footer
    tag: section
    classes: ["footer_group_wrap"]
    height: 714px
    width: 215px
    layout: flex-column justify=normal
    children: 2
  - section: footer
    tag: section
    classes: ["footer_group_wrap"]
    height: 714px
    width: 215px
    layout: flex-column justify=normal
    children: 2
```

**Agent rule**: rebuild sections in this order (sorted by vertical position). Match the layout primitive (grid N-col / flex direction / block).


## 14. Copy Library (Real Content from Source)

*Actual text content extracted from the live page. Use these strings verbatim when reproducing the site — they carry the brand voice.*

```yaml
copy:
  section-headings:
    - "Announcing Fable 5"
    - "Latest releases"
    - "At Anthropic, we build AI to serve humanity’s long-term well-being."
  sub-headings:
    - "Expanding Project Glasswing"
    - "Claude Opus 4.8"
    - "Core views on AI safety"
    - "Products"
  ctas:
    - "Commitments"
    - "Try Claude Try Claude Learn more about Claude"
    - "Try Claude Try Claude"
    - "Try Claude"
    - "Learn more about Claude"
    - "Continue reading"
    - "Read announcement Read announcement"
    - "Model details Model details"
  navigation:
    - "Try Claude"
    - "Skip to main content"
    - "Skip to footer"
    - "Research"
    - "Policy"
    - "News"
    - "research"
    - "products"
    - "Claude"
    - "Claude Code"
  footer-links:
    - "Claude"
```

**Agent rule**: reuse these exact strings when generating UI. Do NOT translate or rephrase — brand voice is preserved through the original wording.


## 16. Component HTML Templates

*Suggested HTML markup for reproducing the key components — based on what was detected in the source DOM.*

### Button (primary action)
```html
<button class="btn btn-primary">
  Commitments
</button>
```
_Source pattern detected: padding `22.4px 12px` · radius `0px` · weight `400`_

**Agent rule**: use these markup skeletons as the structural baseline. Apply tokens from §2-3 for visual styling.


## 17. Content Architecture & Resources (Links by Purpose)

*The page's links classified by purpose — the information architecture to reproduce. Categories, featured images, devices and projects are extracted from the rendered DOM, not guessed.*

**By purpose:** **nav** 6 · **cta** 1 · **auth** 1 · **product** 21 · **pricing** 5 · **docs** 1 · **blog** 6 · **social** 3 · **footer** 7 · **other** 9

**Primary actions (conversion path):**
- Primary call-to-action — "Try Claude" (the conversion path) → `https://claude.ai/`
- Account access — "Log in to Claude" (login/signup) → `https://claude.ai/login`

**Signals:** 5/60 links carry a featured image · device mockups detected: phone ×1 · dominant link roles: footer-link (21), inline-link (16), content-card (16).


---
## Extraction Completeness: 68/100 (C)

| Category | Score | Max | Detail |
|----------|-------|-----|--------|
| Colors & Palette | 14 | 25 | 10 named colors |
| Typography | 20 | 20 | 8 roles defined |
| Components | 4 | 20 | 1 specs extracted |
| Motion & Interaction | 12 | 15 | Keyframes |
| CSS Custom Properties | 10 | 10 | 282 vars |
| Responsive Breakpoints | 3 | 5 | 3 breakpoints |
| Variable Fonts | 5 | 5 | OPSZ axes |

## 12. Known Gaps & Confidence

Explicit list of what this extraction could NOT capture. Agents should not invent values for these — either skip the feature or use the documented baseline + heuristic fallback.

*Auto-detected extraction limitations — understand before building:*

- **Licensed web fonts (webflow-icons, Jetbrains Mono, Anthropic Sans)** — detected but not downloaded. Substitute with your licensed copy or a close fallback (see Typography section for metrics).
- **Sparse component extraction** — fewer than 5 component types detected. Highly dynamic sections (modals, datepickers, carousels) require interaction to render and are not captured in a static pass.

| Category | What's missing | Fallback strategy |
|----------|----------------|-------------------|
| **Photography** | No photographic content detected on this page | Don't add stock imagery; clarity comes from type + color blocks |
| **Form inputs** | No text input fields detected on this page | Use the documented border-radius + accent border on focus; 12-16px padding inside |

### Per-section confidence

| Section | Confidence | Reason |
|---------|------------|--------|
| §1 Visual Theme | High | Body bg extracted via getComputedStyle() |
| §2 Colors | High | 282 CSS vars (semantic naming requires ≥20 for high) |
| §3 Typography | High | 8 typography roles inferred |
| §4 Components | Low | 1 component variants captured |
| §7 Motion | High | Keyframes + transitions |
| §8 Do's/Don'ts | High | 19 rules generated; design-decisions.json has evidence per rule |
| §9 Responsive | High | 3 breakpoints detected |
| §9b Photography | Low | 0 images, hero not detected |

## 11.1 CSS Implementation Guide (CSS Interception Engine v2.15+)

*Ready-to-use CSS from Prism's CSS Interception Engine — intercepted directly from the site's CSS files (bypasses CORS). Copy-paste into your `<style>` block.*

### Font Loading

3 font file(s) captured (352KB total). When running `prism add`, fonts are saved to `extractions/anthropic.com/fonts/` and embedded as base64 in the output HTML.

**@font-face declarations to use:**
```css
@font-face {
  font-family: 'webflow-icons';
  /* src: url('/fonts/webflow-icons.woff2') format('woff'); */
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Jetbrains Mono';
  /* src: url('/fonts/Jetbrains-Mono.woff2') format('woff2'); */
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Anthropic Sans';
  /* src: url('/fonts/Anthropic-Sans.woff2') format('woff2'); */
  font-weight: 300 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Anthropic Sans';
  /* src: url('/fonts/Anthropic-Sans.woff2') format('woff2'); */
  font-weight: 300 800;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: 'Anthropic Serif';
  /* src: url('/fonts/Anthropic-Serif.woff2') format('woff2'); */
  font-weight: 300 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Anthropic Serif';
  /* src: url('/fonts/Anthropic-Serif.woff2') format('woff2'); */
  font-weight: 300 800;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: 'Anthropic Mono';
  /* src: url('/fonts/Anthropic-Mono.woff2') format('woff2'); */
  font-weight: 300 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Anthropic Mono';
  /* src: url('/fonts/Anthropic-Mono.woff2') format('woff2'); */
  font-weight: 300 800;
  font-style: italic;
  font-display: swap;
}
```

### Keyframe Animations (Intercepted from CSS)

**1 @keyframes found** — these are the real animation definitions:

```
@keyframes spin { ... }
```

<details><summary>Full keyframes CSS (1 animations)</summary>

```css
@keyframes spin{0%{transform:rotate(0)}
```
</details>

### Brand Gradient Palette

**1 complex gradients captured** from the site's CSS. The first few are the most prominent visual decorations:

```css
/* Gradient 1 */
background: radial-gradient(circle farthest-side at 50% 50%,var(--swatch--transparent);

```

### Hover State CSS (Intercepted)

**1 hover rule lines** captured from CSS files. Key interactive transitions from real CSS (not inferred):

```css
a:active,a:hover{outline:0}

.w-lightbox-control:hover{opacity:1}

.w-lightbox-inactive,.w-lightbox-inactive:hover{opacity:0}
```

> **Note**: All values above are extracted from the live site's CSS files. The font files are saved locally by Prism and embedded in the output HTML. Use them as-is for maximum fidelity.

## 11.2 Measured Reality (CDP Engine)

Captured directly from Chrome's engine across **all 1391 rendered nodes** — not a sample. These are the values the page *actually paints*, weighted by how often they appear.

### Real Responsive Breakpoints
**5 breakpoints** read from the live `@media` rules (not guessed):
`479px` · `501px` · `767px` · `768px` · `991px`

### Measured Design Scale
**Type scale by usage** (× = paint count): `12px`×506 · `16px`×375 · `20px`×253 · `24px`×106 · `60.8653px`×59 · `18px`×43 · `15px`×22 · `14px`×14

**Radius scale** (× = paint count): `8px`×17 · `16px`×6 · `24px`×4

**Weights** (× = paint count): `400`×1026 · `600`×160 · `500`×145 · `700`×59

**Layout gaps** (× = paint count): `normal 8px`×33 · `31.4776px`×16 · `8px`×12 · `46.4327px`×4 · `16px`×3 · `12px`×2 · `normal 12px`×1 · `0px 28px`×1

**Elevation (real shadows)**:
```css
rgba(0, 0, 0, 0.01) 0px 2px 2px 0px, rgba(0, 0, 0, 0.02) 0px 4px 4px 0px, rgba(0, 0, 0, 0.04) 0px 16px 24px 0px
```

### Provenance — measured styles on key elements
Read from the live CSSOM (includes runtime-injected CSS). This is *what actually styles the page*, by element:

```css
body { color:#333; background-color:#fff; font-family:Arial,sans-serif; font-size:14px }
body { background-color:var(--_color-theme---background); font-family:var(--_text-style---font-family); color:var(--_color-theme---text); font-size:var(--_text-style---font-size); font-weight:var(--_text-style---font-weight) }
main { background-color:var(--swatch--ivory-medium) }
h1 { font-size:2em }
h1 { font-size:38px }
h1 { font-family:var(--_text-style---font-family); font-size:var(--_text-style---font-size); font-weight:var(--_text-style---font-weight) }
h2 { font-size:32px }
h2 { font-family:var(--_typography---font--display-serif-family); font-size:var(--_text-style---font-size); font-weight:var(--_typography---font--display-serif-regular) }
a { background-color:var(--_color-theme---background); font-family:var(--_text-style---font-family); color:var(--_color-theme---text); font-size:var(--_text-style---font-size); font-weight:var(--_typography---font--display-serif-semibold); transition:transform .2s,color .2s }
```

> Selectors normalised to their semantic element — source class names are often build-hashed (`.bgDIHX`) and not reusable. The declarations + CSS vars are the transferable part.

---
*Generated by Prism — automated Playwright extraction + design analysis.*
*Source: https://anthropic.com | 2026-06-11T06:01:23.804Z*
*Values extracted via getComputedStyle() (rendered) + CSS custom properties (tokens, marked `(token)`). Token-only values may not be painted — verify against the live site before shipping.*