--- version: alpha name: posthog.com description: "Light product system built on #eeefe9 with #cd8407 as the primary CTA accent. Type anchored in IBM Plex Sans Variable at 24px / weight 800. Extracted automatically from https://posthog.com/ — rendered styles via getComputedStyle() + CSS custom properties (token-only values may not be painted)." narrative: | posthog.com is built on a warm, off-white canvas (rgb(238, 239, 233)). The system uses rgb(205, 132, 7) as the high-saturation accent for primary actions. Crisp CTAs (4px radius) reinforce a precise, technical aesthetic alongside IBM Plex Sans Variable as the primary typeface. IBM Plex Sans Variable is paired with IBM Plex Sans for secondary roles. A restrained elevation system (2 distinct shadows) — shadows reserved for the few elements that must lift off the page. Motion is a first-class concern — 43 keyframe animations plus transition-driven interactions. colors: background: "#eeefe9" surface-1: "#e5e7e0" surface-2: "#ffffff" ink-muted: "#23251d" ink-subtle: "#23251d" primary: "#cd8407" on-primary: "#111111" primary-hover: "#b17816" hairline: "#bfc1b7" typography: display-xl: fontFamily: "IBM Plex Sans Variable, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif" fontSize: 24px fontWeight: 800 lineHeight: 1.33 letterSpacing: -0.6px display-md: fontFamily: "IBM Plex Sans Variable, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif" fontSize: 19.2857px fontWeight: 600 lineHeight: 1.56 letterSpacing: -0.482143px body: fontFamily: "IBM Plex Sans Variable, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif" fontSize: 16px fontWeight: 400 lineHeight: 1.5 letterSpacing: 0 body-sm: fontFamily: "IBM Plex Sans Variable, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif" fontSize: 15px fontWeight: 600 lineHeight: 1.71 letterSpacing: 0 button: fontFamily: "IBM Plex Sans Variable, 'SF Pro Display', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif" fontSize: 13px fontWeight: 500 lineHeight: 1 letterSpacing: 0 rounded: none: 0px xs: 4px sm: 8px md: 9999px lg: 10007px xl: 10015px pill: 9999px spacing: xxs: 2px xs: 4px sm: 8px md: 16px lg: 40px xl: 48px xxl: 64px components: button-ghost: backgroundColor: "transparent" textColor: "{colors.ink-subtle}" typography: "{typography.button}" rounded: "{rounded.xs}" padding: 2px 8px button-primary-brand: backgroundColor: "{colors.primary}" textColor: "{colors.ink-subtle}" typography: "{typography.body}" rounded: "{rounded.xs}" button-ghost-2: backgroundColor: "transparent" textColor: "{colors.ink-subtle}" typography: "{typography.button}" rounded: "{rounded.xs}" padding: 2px 4px card-standard-card: backgroundColor: "transparent" typography: "{typography.body}" rounded: "{rounded.none}" padding: 16px 32px tab-pill-tab: backgroundColor: "#2f80fa" textColor: "{colors.surface-2}" typography: "{typography.body-sm}" rounded: "{rounded.xs}" padding: 10px 12px code-block-inline-code--pre: backgroundColor: "transparent" textColor: "transparent" typography: "{typography.body-sm}" rounded: "{rounded.xs}" alert-alert-banner: backgroundColor: "{colors.surface-2}" textColor: "#4d4f46" typography: "{typography.body}" rounded: "{rounded.xs}" padding: 16px extracted_at: "2026-06-11T05:02:05.911Z" completeness: 89 scoreVersion: "v2" --- # Design System — posthog.com > Extracted automatically by Prism from https://posthog.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). > ⚠️ **LOW-CONFIDENCE CAPTURE** — this extraction likely sampled an app shell / interactive demo, **not** the marketing page. Signals: button labels look like filenames (home.mdx); editor-chrome labels (Ask a question, Switch to website mode); only 1 card component detected; footer has 0 links. Treat the component, color and copy values below with caution, and re-extract the canonical marketing URL if fidelity matters. ## 0. Design DNA **Density**: moderate  |  **Motion**: expressive  |  **Weight**: heavy  |  **Aesthetic**: product-neutral | Dimension | Value | Signal | |---|---|---| | Canvas | neutral | `#eeefe9` | | Type posture | sans-led (IBM Plex Sans Variable) | "The new way to build products" | | Color assertion | dual-accent | #cd8407 | | Whitespace | moderate | section rhythm 56px | | Interaction | expressive | 43 keyframes, 4 transitions | | Radius language | 6px-rounded | from token scale | **Prism fingerprint**: `neutral-canvas · sans-display · dual-accent · 6px-rounded · expressive-motion` > **🤖 TL;DR for AI agents** (read this first — saves you scanning the full doc): > > - **Canvas**: `rgb(238, 239, 233)` is the page background. Every component composits against this. > - **Accent**: `rgb(205, 132, 7)` for primary CTAs ONLY. Never decorative. > - **Body type**: 16px (token: `typography.body`). Default for ALL text not in a heading role. > - **Section rhythm**: 56px between major bands. Card padding: 40px. > - **Default radius**: 8px 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 posthog.com's canvas is a warm, intentionally-tinted surface (`#eeefe9`) — 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 **IBM Plex Sans Variable**. Headlines use weight 800 for confident, assertive presence — the brand wants to be heard. Negative letter-spacing at display sizes (-0.6px at 24px) compresses headlines into engineered blocks, dense and precise. Body text reads in Pure Black (`#000000`) (contrast ratio 19.7:1, well above WCAG AA). **#cd8407** (`#cd8407`) is the single high-saturation color in the system — it earns its presence only on interactive elements, making CTAs and links the unmistakable focal points against the otherwise neutral palette. Elevation comes from a small, deliberate set of shadows (2 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 WGHT axes, enabling precise weight/width control across the type hierarchy. **Key Characteristics:** - Background: Whitesmoke (`#eeefe9`) - Primary typeface: Source Code Pro - Accent: #cd8407 (`#cd8407`) - Display: 24px weight 800, letter-spacing -0.6px - Shadow system: 2 distinct elevation levels - Custom fonts loaded: Source Code Pro, IBM Plex Sans Variable, Fairytale, Computer Modern, Squeak, Open Runde, Charter ## 2. Color Palette & Roles ### Background & Surface - **Whitesmoke** (`#eeefe9`): Page background (primary) - **Translucent Light Gray (75%)** (`rgba(229, 231, 224, 0.75)`): Surface / elevated background - **Pure White** (`#ffffff`): Surface / elevated background - **Off-White** (`#fdfdf8`): Surface / elevated background - **Off-White** (`#f3f4f0`): Surface / elevated background ### Text & Content - **Pure Black** (`#000000`): Primary body text - **Near-Black** (`#23251d`): Secondary text - **Deep Navy** (`#111827`): Secondary text - **#0500ff** (`#0500ff`): Secondary text - **Near-Black** (`#1f1f1f`): Secondary text ### Accent & Interactive - **#cd8407** (`#cd8407`): Interactive / accent - **Honey** (`#b17816`): Interactive / accent - **#eb9d2a** (`#eb9d2a`): Interactive / accent - **#e1d7c2** (`#e1d7c2`): Interactive / accent - **Dark Gray** (`#374151`): Interactive / accent - **#1d4aff** (`#1d4aff`): Interactive / accent - **#f9bd2b** (`#f9bd2b`): Interactive / accent ### Border & Divider - **Light Grey** (`#bfc1b7`): Borders / dividers - **Grey** (`#b6b7af`): Borders / dividers - **Translucent Silver (50%)** (`rgba(210, 211, 204, 0.5)`): Borders / dividers - **Light Grey** (`#d0d1c9`): Borders / dividers - **Light Grey** (`#dad7d4`): Borders / dividers ### Full Extracted Palette **253 colors rendered on the page** + **3** more declared in design tokens (CSS custom properties — not necessarily painted). (22 categorized above + 234 additional below.) Rendered values are read via `getComputedStyle()`; token values come from CSS variable declarations. Third-party logo colors are filtered out. - `#65675e` — Slate Grey - `#4d4f46` — Charcoal - `#9ea096` — Grey - `#73756b` — Slate Grey - `#f54e00` — Bright Orange - `#2f80fa` — Ring Blue - `#b62ad9` — #b62ad9 - `#36c46f` — #36c46f - `#f7a501` — Amber - `#6aa84f` — #6aa84f - `#30abc6` — #30abc6 - `#29dbbb` — #29dbbb - `#ff5a00` — Bright Orange - `#fffefe` — Pure White - `#4b73ff` — Ring Blue - `#ff66f4` — Magenta - `#ff0105` — Red - `#fe7b02` — #fe7b02 - `#20c178` — Emerald - `#40ba9b` — #40ba9b - `#ab81e9` — #ab81e9 - `#00ba97` — Emerald - `#128414` — Forest Green - `#0079ff` — #0079ff - `#00e1ff` — #00e1ff - `#3ecf8e` — #3ecf8e - `#f7d046` — #f7d046 - `#f2a73b` — #f2a73b - `#ee792f` — Coral - `#eb5829` — Vermillion - `#ea3326` — M Tricolor Red - `#1f40ec` — #1f40ec - *…+202 more in `raw-css.json` (`desktop.allColors`).* ### CSS Custom Properties (Design Tokens) **Shadow Token** - `--tw-ring-offset-shadow`: `0 0 #0000` - `--tw-ring-shadow`: `0 0 #0000` - `--tw-shadow`: `0 0 #0000` - `--tw-shadow-colored`: `0 0 #0000` **Spacing Token** - `--tw-numeric-spacing`: `` - `--tw-border-spacing-x`: `0` - `--tw-border-spacing-y`: `0` - `--viewport-padding`: `25px` **Other tokens** - `--squeak-button-color`: `245,78,0` - `--swiper-pagination-bullet-inactive-color`: `#000` - `--squeak-primary-color`: `0,0,0` - `--tw-ring-color`: `rgba(59,130,246,.5)` - `--swiper-theme-color`: `#007aff` - `--swiper-pagination-color`: `#f54e00` - `--tw-ring-offset-color`: `#fff` - `--tw-text-opacity`: `1` ## 3. Typography Rules ### Font Families - **Primary**: `IBM Plex Sans Variable` - **Secondary**: `Source Code Pro` - **Font 3**: `Fairytale` - **Font 4**: `Computer Modern` - **Font 5**: `Squeak` ### Custom Fonts Loaded - **Source Code Pro** weight 400 (normal) - **IBM Plex Sans Variable** weight 100 700 (normal) - **Fairytale** weight 400 (normal) - **Computer Modern** weight 400 (normal) - **Squeak** weight 700 (normal) - **Open Runde** weight 400 (normal) - **Open Runde** weight 500 (normal) - **Open Runde** weight 600 (normal) - **Open Runde** weight 700 (normal) - **Charter** weight 400 (normal) - **Charter** weight 700 (normal) - **swiper-icons** weight 400 (normal) ### Typography Hierarchy | Role | Font | Size | Weight | Line Height | Letter Spacing | Notes | |------|------|------|--------|-------------|----------------|-------| | Display Hero | IBM Plex Sans Variable | 24px | 800 | 1.33 | -0.6px | Main headline (h1) | | Sub-heading | IBM Plex Sans Variable | 19.2857px | 600 | 1.56 | -0.482143px | Third-level heading (h3) | | Body | IBM Plex Sans Variable | 16px | 400 | 1.5 | normal | Standard reading text | | Card Title | IBM Plex Sans Variable | 15px | 400 | 1.71 | normal | Card headings | | Link | IBM Plex Sans Variable | 15px | 600 | 1.71 | normal | Link (15px) — Decoration: none | | Button | IBM Plex Sans Variable | 13px | 500 | 1 | normal | Button label (13px) | | Button | IBM Plex Sans Variable | 13px | 400 | 1.5 | normal | Button label (13px) | ### Full Font Size Scale Sizes detected in the design (descending): `36px`, `24px`, `21.43px`, `20px`, `19.29px`, `18px`, `16px`, `15px`, `14px`, `13px`, `12px` > 6 size(s) detected outside the sampled hierarchy (36px, 21.4286px, 20px, 18px, 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:** - WGHT axis ## 4. Component Stylings ### Buttons **Ghost** - Background: `transparent` - Text: `#23251d` `{colors.ink-subtle}` - Padding: 2px 8px - Radius: 4px - Font: 13px weight 500 - Use: Subtle action, toolbar, nav button - Focus: backgroundColor: `rgb(200, 202, 193)` **Primary Brand** - Background: `#cd8407` `{colors.primary}` - Text: `#23251d` `{colors.ink-subtle}` - Padding: 0px - Radius: 6px - Border: 1px solid rgb(177, 120, 22) - Font: 16px weight 400 - Use: Primary CTA / brand action - Focus: backgroundColor: `rgb(200, 202, 193)` **Ghost** - Background: `transparent` - Text: `#23251d` `{colors.ink-subtle}` - Padding: 2px 4px - Radius: 4px - Border: 1px solid rgba(0, 0, 0, 0) - Font: 13px weight 400 - Use: Subtle action, toolbar, nav button - Focus: backgroundColor: `rgb(200, 202, 193)` **Light / Invert** - Background: `#e5e7e0` `{colors.surface-1}` - Text: `#65675e` - Padding: 4px 6px - Radius: 4px - Font: 16px weight 400 - Use: Bright CTA on dark sections - Focus: backgroundColor: `rgb(200, 202, 193)` **Subtle** - Background: `rgba(210, 211, 204, 0.5)` - Text: `#23251d` `{colors.ink-subtle}` - Padding: 12px 8px 4px 20px - Radius: 0px 0px 6px 6px - Font: 12px weight 400 - Use: Quiet action against page bg - Focus: backgroundColor: `rgb(200, 202, 193)` ### Cards & Containers **Standard Card** - Background: `transparent` - Padding: 16px 32px - Radius: 0px - Use: Content containers, listing items ### Tabs **Pill Tab** - Background: `#2f80fa` - Text: `#ffffff` `{colors.surface-2}` - Padding: 10px 12px - Radius: 6px 6px 0px 0px - Font: 14px weight 600 - Use: Navigation tabs, filter tabs ### Code Blocks **Inline Code / Pre** - Background: `transparent` - Text: `transparent` - Padding: 0px - Radius: 4px - Font: 14px weight 500 — "Source Code Pro" - Use: Code samples, CLI commands, syntax highlighting blocks ### Alerts **Alert Banner** - Background: `#ffffff` `{colors.surface-2}` - Text: `#4d4f46` - Padding: 16px - Radius: 6px - Border: 1px solid rgb(191, 193, 183) - Font: 16px weight 400 - Use: System alert, banner notification, toast ## 4b. Component Behaviors (State Matrix) ### Interaction State Narrative - **Button**: - **focus:** bg transparent → #c8cac1 *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(35, 37, 29)" focus: bg: "rgb(200, 202, 193)" fg: "inherit" link: default: bg: "rgba(0, 0, 0, 0)" fg: "rgb(77, 79, 70)" card: default: bg: "rgba(0, 0, 0, 0)" fg: "rgb(55, 65, 81)" navLink: default: bg: "rgba(0, 0, 0, 0)" fg: "rgb(77, 79, 70)" tab: default: bg: "rgba(0, 0, 0, 0)" fg: "rgb(101, 103, 94)" ``` **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`, `Primary Brand`, `Light / Invert`, `Subtle` - **DO NOT introduce new buttons variants** without justification ### Cards & Containers - **1 shape(s)** in this system: `Standard Card` - **DO NOT introduce new cards & containers variants** without justification ### Tabs - **1 shape(s)** in this system: `Pill Tab` - **DO NOT introduce new tabs variants** without justification ### Code Blocks - **1 shape(s)** in this system: `Inline Code / Pre` - **DO NOT introduce new code blocks variants** without justification ### Alerts - **1 shape(s)** in this system: `Alert Banner` - **DO NOT introduce new alerts variants** without justification ## 5. Layout Principles ### Layout Type **top-nav + content** ### Grid Flexbox column ### Max Width 1200px ### Spacing System Generous spacing — editorial breathing room | Token | Value | |-------|-------| | xxs | 2px | | xs | 4px | | sm | 8px | | md | 16px | | base | 32px | | lg | 40px | | xl | 48px | | 2xl | 56px | | 3xl | 64px | ### Border Radius Scale | Name | Value | Use | |------|-------|-----| | None | 0px | No rounding | | Xs | 4px | Tiny corners (badges, micro elements) | | Sm | 8px | Buttons, inputs, small elements | | Md | 9999px | Cards, containers | | Lg | 10007px | Large rounded elements, pill segments | | Xl | 10015px | Category strips, featured containers | | Full | 9999px | Pills, avatars, circular elements | ### Shape Language | Component | Border Radius | |-----------|---------------| | Buttons | `4px` | | Cards & Containers | `0px` | | Tabs | `6px 6px 0px 0px` | | Code Blocks | `4px` | | Alerts | `6px` | | Page Body | `0px` | | Navigation | `0px` | **Shape Personality**: Moderate Rounding — Medium corners (4–12px). Modern SaaS standard, neither sharp nor pill. **Full Radius Spectrum**: 0px, 2px, 4px, 5px, 6px, 8px, full/pill (from `allBorderRadii` scan) ## 5b. Spacing Rhythm Names *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** | `48px` | Between major bands (color change, content shift) | | **subsection** | `40px` | Within a section, between content groups | | **card** | `16px` | 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:** split-left-text — Split layout, text-left/media-right — heading + body in left column, image/illustration in right column. Common for product showcases. - **Viewport coverage:** full-viewport hero (≥70% screen height) - **Heading:** "" — 24px left-aligned - **Subheading:** "The new way to build productsProduct development used to mean manually writing code, running analysis, diagnosing bugs, and rolling out changes using " - **Media:** present, positioned right - **CTAs:** 13 (primary: "Get started - free") - **Clone instruction:** Reproduce the **split-left-text** layout. Use the heading font-size token at the documented size. Place media right of text. ### Card Grid Pattern - **Card count:** 4 cards detected - **Columns (desktop):** 4-up grid - **Card dimensions:** 384×108px (aspect 3.55:1) - **Gap:** 16px between cards - **Content:** ✗ no image + icon - **Clone instruction:** Build a 4-column grid (desktop) with cards at ~3.55:1 aspect ratio. Text/icon-only cards (no photography). ### Pricing Table Pattern - **Tier count:** 2 pricing tiers - **Layout:** vertical stacked - **Columns (desktop):** 2-up - **Feature list:** ✓ (median ~10 feature points per tier) - **Clone instruction:** Build a 2-column vertical-stack pricing comparison. ### Footer Pattern - **Columns:** 1 - **Links:** 0 total - **Height:** 6px - **Includes:** ✗ no newsletter | ✗ no social | - **Clone instruction:** Build a 1-column footer with ~0 links per column. ## 6. Depth & Elevation | Level | Treatment | Use | |-------|-----------|-----| | Flat (Level 0) | No shadow | Page background, content blocks | | Layered (Level 1) |
`rgba(0, 0, 0, 0.25) 0px 25px 50px -12px` | Cards, elevated surfaces | | Layered (Level 2) |
`rgba(0, 0, 0, 0.2) 0px 0px 6px 2px` | 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(0.4,0,0.2,1)` | Material Standard — Balanced | ### Duration Scale | Value | Tier | Typical Use | |-------|------|-------------| | `150ms` | Fast | Hover states, micro-interactions | | `300ms` | Normal | Panel open/close, navigation | ### Copy-Paste Transition Snippets **All Props** ```css transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1); ``` **Color / Background** ```css transition: color 0.15s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.15s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.15s cub...; ``` **All Props** ```css transition: 0.15s cubic-bezier(0.4, 0, 0.2, 1); ``` ### Keyframe Animation Catalog | Animation Name | Type | Animated Props | Use Hint | |----------------|------|----------------|----------| | `slideRight` | Slide | transform | UI transition | | `rcSliderTooltipZoomDownIn` | Fade + Move | opacity, transform, transform-origin | Focus / emphasis | | `rcSliderTooltipZoomDownOut` | Fade + Move | transform, transform-origin, opacity | Focus / emphasis | | `wobble` | Rotate / Spin | transform | UI transition | | `breathe` | Scale | transform | UI transition | | `develop` | Fade | filter, opacity | UI transition | | `flash` | Scale | transform | UI transition | | `float` | Slide | transform | UI transition | | `gradient-rotate` | Custom | background-position-x, background-position-y | Loading indicator | | `grow` | Scale | transform | UI transition | | `grow-sm` | Scale | transform | UI transition | | `hogfather-jump` | Custom | margin-top | UI transition | | `hogfather-roll` | Scale | left, transform | UI transition | | `jump-out` | Scale | transform | UI transition | | `ping` | Fade + Move | opacity, transform | Attention / status | | `pulse` | Fade | opacity | Attention / status | | `shimmer` | Custom | background-position-x, background-position-y | Loading placeholder | | `slideUpFadeIn` | Fade + Move | opacity, transform | Element entrance | | `spin` | Rotate / Spin | transform | Loading indicator | | `wiggle` | Rotate / Spin | transform | Playful feedback | > *23 additional animations omitted (repetitive variants). See raw keyframes in `raw-css.json`.* ### Motion Fingerprint - **Speed Character**: Deliberate & Calm (median duration: `300ms`) - **Dominant Easing**: custom cubic-bezier curves - **Animation Library**: 43 unique animations (43 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 Whitesmoke (`#eeefe9`) as the page background — it's intentionally not pure white - Use IBM Plex Sans Variable as the primary typeface — it defines the brand personality - Use negative letter-spacing (-0.6px) at display sizes for compressed, editorial headlines - 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 #cd8407 (`#cd8407`) as the primary accent — it's the brand's signature interactive color - Use 6px border-radius on buttons — the standard corner rounding for interactive elements - Apply 16px 32px padding inside cards — matches the design system's content breathing room - Respect the 4px–48px spacing range — the design uses a wide scale for visual breathing room - Make the hero full-viewport (≥70% screen height) — this design uses an immersive hero, not a tall navbar - Build the hero as a split layout with media on the left — text and visual share equal weight - Include exactly 13 CTAs in the hero (primary + secondary) — this design pattern is multi-action, not single-purpose - Each card uses an icon (not photo) — the visual language is illustrative, not photographic - Use a 4-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 substitute with generic sans-serif or serif — the custom font carries the brand - Don't increase letter-spacing on headings — the type is designed to run tight at scale - 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 over-build the footer — this design keeps it minimal (1 cols, 0 links) ## 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(238, 239, 233)` as the base canvas" why: "Every component is designed to composit against this exact tone" test: "document.body.style.backgroundColor === 'rgb(238, 239, 233)'" - id: brand-accent-001 type: do rule: "Reserve `rgb(205, 132, 7)` for primary CTAs and brand-mark signals only" why: "Single chromatic assertion device — overuse dilutes meaning" test: "querySelectorAll('[style*=\"rgb(205, 132, 7)\"]').length <= 3 per fold" ``` ## 9. Responsive Behavior ### Breakpoints | Name | Width | Key Changes | |------|-------|-------------| | Mobile | 425px | Single column, compact spacing | | Mobile Large | 482px | Expanded mobile layout | | Mobile Large | 640px | Expanded mobile layout | | Mobile Large | 767px | Expanded mobile layout | | Tablet | 1024px | Multi-column grids begin | | Desktop | 1280px | Full feature layout | ### Token Diff — Desktop vs Mobile | Element | Property | Desktop | Mobile | |---------|----------|---------|--------| | nav | display | `block` | `flex` | | button | width | `40px` | `80px` | | card | padding | `16px 32px` | `16px` | | card | width | `896px` | `388px` | | sidebar | width | `267px` | `237px` | ### Collapsing Strategy - Navigation: block → flex on mobile - Cards: multi-column → stacked vertical on mobile - Footer: multi-column → stacked single column on mobile ### Touch Targets - Buttons: 2px 8px 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): - **Hero collapses split-left-text → centered** — the side-by-side layout stacks vertically, with media moving above the text. - **Hero CTAs:** 13 on desktop → 4 on mobile (secondary CTAs dropped on small screens). - **Card grid: 4-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.* - **Glassmorphism** — 3 frosted/blur layer(s) (e.g. `blur(8px)`). - **Clip-path shapes** — 8 non-rectangular cut(s). - **CSS-variable animations** (4) — animated custom properties. > **Motion fingerprint**: glassmorphism (3 layers), non-rectangular shapes (10) ## 9b. Visual Tone & Photography **Tone:** Mixed photography + illustration A balanced mix of photographic content and vector graphics. Photos likely carry product/lifestyle context while SVG handles icons, logos, and decorative accents. **Canonical Brand Image (OG):** - https://posthog.com/images/og/default.png *This is the image shown when the site is shared on social media — represents the brand visual essence.* **Hero Image (above-fold dominant visual):** - Aspect: 1:1 (square / portrait) - Rendered size: 700×700px - *Use this aspect ratio + composition for your clone's hero — mimicking the proportion preserves the visual hierarchy.* **Aspect Ratio Distribution:** - Landscape (1.15–2.3): 4 (44%) - Portrait (<0.87): 1 (11%) - Square (0.87–1.15): 4 (44%) **Media Format Mix:** - SVG: 1 (icons, illustrations, decorative geometry) **Average rendered image size:** 315×255px **Above-fold image count:** 4 / 9 **Decorative Patterns Detected:** - 1 multi-stop linear gradient (mesh-like, 3+ color stops) — the brand leans on rich color transitions for visual depth - 1 large decorative SVG shape (≥200×200px, non-icon) — likely blob/illustration accents - **Glassmorphism** detected (`backdrop-filter: blur`) — layered transparent surfaces with blur, modern OS-like aesthetic **Clone instruction for decorative work:** Glassmorphism is a brand signature — use `backdrop-filter: blur(20px)` on overlapping surfaces. **Imagery Guidance for clones:** - Mix photography and illustration intentionally: photos for product/context, vectors for icons + decorative accents. - Respect the format split — replacing JPGs with illustrations (or vice versa) will shift the brand tone. ## 10. Agent Prompt Guide ### Quick Reference - Background: Whitesmoke (`#eeefe9`) - Primary text: Pure Black (`#000000`) - Accent: #cd8407 (`#cd8407`) - Border: Light Grey (`#bfc1b7`) - Font: IBM Plex Sans Variable - Body: 16px weight 400 ### Example Component Prompts - "Create a hero section on Whitesmoke background (#eeefe9). Headline at 24px IBM Plex Sans Variable weight 800, line-height 1.33, letter-spacing -0.6px, color #000000." - "Create the primary CTA button: `#cd8407` background, `#23251d` text, 6px border-radius, 12px 24px padding, 700 weight, IBM Plex Sans Variable font." - "Design a card on `transparent` background. Border: none. Radius: 0px. Shadow: none. Padding: 16px 32px." - "Build navigation: static on `#eeefe9`. IBM Plex Sans Variable 16px weight 400 for links." ### Iteration Guide 1. **Canvas**: Set the light canvas to Whitesmoke (`#eeefe9`) — every component is composited against this exact base. 2. **Typography**: All type in IBM Plex Sans Variable, weight range 400–800. Never exceed 800 — heavier weights break the brand's tonal restraint. 3. **Accent**: #cd8407 (`#cd8407`) is the sole interactive color. On hover → Honey (`#b17816`). Use CSS transitions, not opacity/brightness filters. 4. **Motion**: All transitions use `cubic-bezier(0.4,0,0.2,1)`. Never use linear for UI transitions — preserve the brand's easing personality. 5. **Shape**: CTAs at `4px`, cards at `0px`. Apply border-radius from the extracted scale only — don't invent intermediate values. 6. **Spacing**: Use the `--ca-space-*` token scale (4px–48px). 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: #eeefe9; --ca-surface-1: #e5e7e0; --ca-surface-2: #ffffff; --ca-ink-subtle: #23251d; --ca-primary: #cd8407; --ca-on-primary: #111111; --ca-primary-hover: #b17816; --ca-hairline: #bfc1b7; } /* Typography */ :root { --ca-font-primary: "IBM Plex Sans Variable", system-ui, sans-serif; --ca-text-display: 24px; --ca-text-body: 16px; --ca-text-small: 15px; --ca-text-button: 13px; } /* Spacing & Radius */ :root { --ca-space-xxs: 2px; --ca-space-xs: 4px; --ca-space-sm: 8px; --ca-space-md: 16px; --ca-space-base: 32px; --ca-space-lg: 40px; --ca-space-xl: 48px; --ca-space-2xl: 56px; --ca-space-3xl: 64px; --ca-radius-none: 0px; --ca-radius-xs: 4px; --ca-radius-sm: 8px; --ca-radius-md: 9999px; --ca-radius-lg: 10007px; --ca-radius-xl: 10015px; --ca-radius-full: 9999px; } ``` ## 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: feature-section tag: div classes: ["@container", "absolute", "!select-auto", "flex"] height: 810px width: 960px layout: flex-column justify=normal children: 7 - section: feature-section tag: div classes: ["@container", "w-full", "h-full", "flex"] height: 771px width: 958px layout: flex-column justify=normal children: 2 - section: feature-section tag: main classes: ["@container/editor", "flex-1", "relative", "h-full"] height: 714px width: 958px layout: flex-column justify=normal children: 1 bg: "rgb(253, 253, 248)" - section: content-section tag: div classes: ["@container"] height: 471px width: 832px layout: block children: 1 - section: content-section tag: div classes: ["data-[state=active]:animate-[hero-carousel-fade-in_300ms_ease-out]", "flex-1"] height: 415px width: 816px layout: block children: 1 - section: content-section tag: div classes: ["OSTable", "md:@2xs/not-full-width:mx-0", "mb-2", "-mx-4"] height: 245px width: 864px layout: block children: 1 - section: content-section tag: div classes: ["md:@2xs/not-full-width:px-0", "flex", "px-4", "@md/reader-content-container:px-6"] height: 245px width: 864px layout: flex-row justify=normal children: 1 padding: "0px 16px" - section: content-section tag: section classes: ["pt-8", "@xl:pt-0", "px-5", "lg:px-0"] height: 512px width: 832px layout: block children: 2 vertical-padding: ~32px ``` **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: - "Understand what users are doing" sub-headings: - "Install with AI in a single prompt" ctas: - "Get started – free" - "Ask a question" - "Switch to website mode" - "home.mdx" navigation: - "home.mdx" - "Product OS" - "Pricing" - "customers.mdx" - "demo.mov" - "Docs" - "Talk to a human" - "Sign up ↗" - "Why PostHog?" - "Changelog" ``` **Agent rule**: reuse these exact strings when generating UI. Do NOT translate or rephrase — brand voice is preserved through the original wording. ## 15. Asset Inventory (Image Roles & Ratios) *Image inventory classified by role and aspect ratio. When reproducing the site, allocate this number of assets per role.* ```yaml assets: logo: count: 1 avg-ratio: 2.22 common-aspect: "~16:9 landscape" sample-alts: - "Ursula von der Leyen, President of the European Commission" product: count: 4 avg-ratio: 1.01 common-aspect: "~1:1 square" ``` **Agent rule**: when generating placeholder images, match these counts and aspect ratios. Use neutral placeholder backgrounds for `product` (e.g. `#f5f5f5`), full-color photography hints for `hero` and `editorial`. ## 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 ``` _Source pattern detected: padding `2px 8px` · radius `4px` · weight `500`_ ### Generic Card ```html
``` _Source pattern detected: padding `16px 32px` · radius `0px` · shadow `none`_ **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** 7 · **cta** 3 · **product** 1 · **pricing** 2 · **docs** 4 · **blog** 3 · **project** 9 · **other** 26 **Primary actions (conversion path):** - Primary call-to-action — "Sign up ↗" (the conversion path) → `https://app.posthog.com/signup` - Primary call-to-action — "Get started – free" (the conversion path) → `https://app.posthog.com/signup` - Primary call-to-action — "Get started - free" (the conversion path) → `https://app.posthog.com/signup` **Projects / case studies detected** (clustered by URL + featured image): *Customers* — high confidence, 7 items: | Title | Featured image | Link | |---|---|---| | Ycombinator | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/ycombinator | | Lovable | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/lovable | | Researchgate | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/researchgate | | Supabase | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/supabase | | Elevenlabs | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/elevenlabs | | Exa | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/exa | | Hasura | `lazy_a2afd552f7` (ar 1) | https://posthog.com/customers/hasura | **Signals:** 44/55 links carry a featured image · dominant link roles: content-card (36), inline-link (9), navigation (7). --- ## Extraction Completeness: 89/100 (B) | Category | Score | Max | Detail | |----------|-------|-----|--------| | Colors & Palette | 25 | 25 | 22 named colors | | Typography | 18 | 20 | 7 roles defined | | Components | 20 | 20 | 5 specs extracted | | Motion & Interaction | 12 | 15 | Keyframes | | CSS Custom Properties | 5 | 10 | 99 vars | | Responsive Breakpoints | 5 | 5 | 6 breakpoints | | Variable Fonts | 5 | 5 | WGHT 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. | Category | What's missing | Fallback strategy | |----------|----------------|-------------------| | **Dark mode** | No dark-mode CSS variables or media queries detected | Light mode is canonical; do not generate dark-mode variants unless explicitly requested | | **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 | 99 CSS vars (semantic naming requires ≥20 for high) | | §3 Typography | High | 7 typography roles inferred | | §4 Components | High | 5 component variants captured | | §7 Motion | High | Keyframes + transitions | | §8 Do's/Don'ts | High | 21 rules generated; design-decisions.json has evidence per rule | | §9 Responsive | High | 6 breakpoints detected | | §9b Photography | High | 9 images, hero present | ## 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 `