# Design System Inspiration of Airbnb

## 1. Visual Theme & Atmosphere

Airbnb's website is a warm, photography-forward marketplace that feels like flipping through a travel magazine where every page invites you to book. The design operates on a foundation of pure white (`#ffffff`) with the iconic Rausch Red (`#ff385c`) — named after Airbnb's first street address — serving as the singular brand accent. The result is a clean, airy canvas where listing photography, category icons, and the red CTA button are the only sources of color.

The typography uses Airbnb Cereal VF — a custom variable font that's warm and approachable, with rounded terminals that echo the brand's "belong anywhere" philosophy. The font operates in a tight weight range: 500 (medium) for most UI, 600 (semibold) for emphasis, and 700 (bold) for primary headings. Slight negative letter-spacing (-0.18px to -0.44px) on headings creates a cozy, intimate reading experience rather than the compressed efficiency of tech companies.

What distinguishes Airbnb is its palette-based token system (`--palette-*`) and multi-layered shadow approach. The primary card shadow uses a three-layer stack (`rgba(0,0,0,0.02) 0px 0px 0px 1px, rgba(0,0,0,0.04) 0px 2px 6px, rgba(0,0,0,0.1) 0px 4px 8px`) that creates a subtle, warm lift. Combined with generous border-radius (8px–32px), circular navigation controls (50%), and a category pill bar with horizontal scrolling, the interface feels tactile and inviting — designed for browsing, not commanding.

**Key Characteristics:**
- Pure white canvas with Rausch Red (`#ff385c`) as singular brand accent
- Airbnb Cereal VF — custom variable font with warm, rounded terminals
- Palette-based token system (`--palette-*`) for systematic color management
- Three-layer card shadows: border ring + soft blur + stronger blur
- Generous border-radius: 8px buttons, 14px badges, 20px cards, 32px large elements
- Circular navigation controls (50% radius)
- Photography-first listing cards — images are the hero content
- Near-black text (`#222222`) — warm, not cold
- Luxe Purple (`#460479`) and Plus Magenta (`#92174d`) for premium tiers

## 2. Color Palette & Roles

### Primary Brand
- **Rausch Red** (`#ff385c`): `--palette-bg-primary-core`, primary CTA, brand accent, active states
- **Deep Rausch** (`#e00b41`): `--palette-bg-tertiary-core`, pressed/dark variant of brand red
- **Error Red** (`#c13515`): `--palette-text-primary-error`, error text on light
- **Error Dark** (`#b32505`): `--palette-text-secondary-error-hover`, error hover

### Premium Tiers
- **Luxe Purple** (`#460479`): `--palette-bg-primary-luxe`, Airbnb Luxe tier branding
- **Plus Magenta** (`#92174d`): `--palette-bg-primary-plus`, Airbnb Plus tier branding

### Text Scale
- **Near Black** (`#222222`): `--palette-text-primary`, primary text — warm, not cold
- **Focused Gray** (`#3f3f3f`): `--palette-text-focused`, focused state text
- **Secondary Gray** (`#6a6a6a`): Secondary text, descriptions
- **Disabled** (`rgba(0,0,0,0.24)`): `--palette-text-material-disabled`, disabled state
- **Link Disabled** (`#929292`): `--palette-text-link-disabled`, disabled links

### Interactive
- **Legal Blue** (`#428bff`): `--palette-text-legal`, legal links, informational
- **Border Gray** (`#c1c1c1`): Border color for cards and dividers
- **Light Surface** (`#f2f2f2`): Circular navigation buttons, secondary surfaces

### Surface & Shadows
- **Pure White** (`#ffffff`): Page background, card surfaces
- **Card Shadow** (`rgba(0,0,0,0.02) 0px 0px 0px 1px, rgba(0,0,0,0.04) 0px 2px 6px, rgba(0,0,0,0.1) 0px 4px 8px`): Three-layer warm lift
- **Hover Shadow** (`rgba(0,0,0,0.08) 0px 4px 12px`): Button hover elevation

## 3. Typography Rules

### Font Family
- **Primary**: `Airbnb Cereal VF`, fallbacks: `Circular, -apple-system, system-ui, Roboto, Helvetica Neue`
- **OpenType Features**: `"salt"` (stylistic alternates) on specific caption elements

### Hierarchy

| Role | Font | Size | Weight | Line Height | Letter Spacing | Notes |
|------|------|------|--------|-------------|----------------|-------|
| Section Heading | Airbnb Cereal VF | 28px (1.75rem) | 700 | 1.43 | normal | Primary headings |
| Card Heading | Airbnb Cereal VF | 22px (1.38rem) | 600 | 1.18 (tight) | -0.44px | Category/card titles |
| Card Heading Medium | Airbnb Cereal VF | 22px (1.38rem) | 500 | 1.18 (tight) | -0.44px | Lighter variant |
| Sub-heading | Airbnb Cereal VF | 21px (1.31rem) | 700 | 1.43 | normal | Bold sub-headings |
| Feature Title | Airbnb Cereal VF | 20px (1.25rem) | 600 | 1.20 (tight) | -0.18px | Feature headings |
| UI Medium | Airbnb Cereal VF | 16px (1.00rem) | 500 | 1.25 (tight) | normal | Nav, emphasized text |
| UI Semibold | Airbnb Cereal VF | 16px (1.00rem) | 600 | 1.25 (tight) | normal | Strong emphasis |
| Button | Airbnb Cereal VF | 16px (1.00rem) | 500 | 1.25 (tight) | normal | Button labels |
| Body / Link | Airbnb Cereal VF | 14px (0.88rem) | 400 | 1.43 | normal | Standard body |
| Body Medium | Airbnb Cereal VF | 14px (0.88rem) | 500 | 1.29 (tight) | normal | Medium body |
| Caption Salt | Airbnb Cereal VF | 14px (0.88rem) | 600 | 1.43 | normal | `"salt"` feature |
| Small | Airbnb Cereal VF | 13px (0.81rem) | 400 | 1.23 (tight) | normal | Descriptions |
| Tag | Airbnb Cereal VF | 12px (0.75rem) | 400–700 | 1.33 | normal | Tags, prices |
| Badge | Airbnb Cereal VF | 11px (0.69rem) | 600 | 1.18 (tight) | normal | `"salt"` feature |
| Micro Uppercase | Airbnb Cereal VF | 8px (0.50rem) | 700 | 1.25 (tight) | 0.32px | `text-transform: uppercase` |

### Principles
- **Warm weight range**: 500–700 dominate. No weight 300 or 400 for headings — Airbnb's type is always at least medium weight, creating a warm, confident voice.
- **Negative tracking on headings**: -0.18px to -0.44px letter-spacing on display creates intimate, cozy headings rather than cold, compressed ones.
- **"salt" OpenType feature**: Stylistic alternates on specific UI elements (badges, captions) create subtle glyph variations that add visual interest.
- **Variable font precision**: Cereal VF enables continuous weight interpolation, though the design system uses discrete stops at 500, 600, and 700.

## 4. Component Stylings

### Buttons

**Primary Dark**
- Background: `#222222` (near-black, not pure black)
- Text: `#ffffff`
- Padding: 0px 24px
- Radius: 8px
- Hover: transitions to error/brand accent via `var(--accent-bg-error)`
- Focus: `0 0 0 2px var(--palette-grey1000)` ring + scale(0.92)

**Circular Nav**
- Background: `#f2f2f2`
- Text: `#222222`
- Radius: 50% (circle)
- Hover: shadow `rgba(0,0,0,0.08) 0px 4px 12px` + translateX(50%)
- Active: 4px white border ring + focus shadow
- Focus: scale(0.92) shrink animation

### Cards & Containers
- Background: `#ffffff`
- Radius: 14px (badges), 20px (cards/buttons), 32px (large)
- Shadow: `rgba(0,0,0,0.02) 0px 0px 0px 1px, rgba(0,0,0,0.04) 0px 2px 6px, rgba(0,0,0,0.1) 0px 4px 8px` (three-layer)
- Listing cards: full-width photography on top, details below
- Carousel controls: circular 50% buttons

### Inputs
- Search: `#222222` text
- Focus: `var(--palette-bg-primary-error)` background tint + `0 0 0 2px` ring
- Radius: depends on context (search bar uses pill-like rounding)

### Navigation
- White sticky header with search bar centered
- Airbnb logo (Rausch Red) left-aligned
- Category filter pills: horizontal scroll below search
- Circular nav controls for carousel navigation
- "Become a Host" text link, avatar/menu right-aligned

### Image Treatment
- Listing photography fills card top with generous height
- Image carousel with dot indicators
- Heart/wishlist icon overlay on images
- 8px–14px radius on contained images

## 5. Layout Principles

### Spacing System
- Base unit: 8px
- Scale: 2px, 3px, 4px, 6px, 8px, 10px, 11px, 12px, 15px, 16px, 22px, 24px, 32px

### Grid & Container
- Full-width header with centered search
- Category pill bar: horizontal scrollable row
- Listing grid: responsive multi-column (3–5 columns on desktop)
- Full-width footer with link columns

### Whitespace Philosophy
- **Travel-magazine spacing**: Generous vertical padding between sections creates a leisurely browsing pace — you're meant to scroll slowly, like browsing a magazine.
- **Photography density**: Listing cards are packed relatively tightly, but each image is large enough to feel immersive.
- **Search bar prominence**: The search bar gets maximum vertical space in the header — finding your destination is the primary action.

### Border Radius Scale
- Subtle (4px): Small links
- Standard (8px): Buttons, tabs, search elements
- Badge (14px): Status badges, labels
- Card (20px): Feature cards, large buttons
- Large (32px): Large containers, hero elements
- Circle (50%): Nav controls, avatars, icons

## 6. Depth & Elevation

| Level | Treatment | Use |
|-------|-----------|-----|
| Flat (Level 0) | No shadow | Page background, text blocks |
| Card (Level 1) | `rgba(0,0,0,0.02) 0px 0px 0px 1px, rgba(0,0,0,0.04) 0px 2px 6px, rgba(0,0,0,0.1) 0px 4px 8px` | Listing cards, search bar |
| Hover (Level 2) | `rgba(0,0,0,0.08) 0px 4px 12px` | Button hover, interactive lift |
| Active Focus (Level 3) | `rgb(255,255,255) 0px 0px 0px 4px` + focus ring | Active/focused elements |

**Shadow Philosophy**: Airbnb's three-layer shadow system creates a warm, natural lift. Layer 1 (`0px 0px 0px 1px` at 0.02 opacity) is an ultra-subtle border. Layer 2 (`0px 2px 6px` at 0.04) provides soft ambient shadow. Layer 3 (`0px 4px 8px` at 0.1) adds the primary lift. This graduated approach creates shadows that feel like natural light rather than CSS effects.

## 7. Do's and Don'ts

### Do
- Use `#222222` (warm near-black) for text — never pure `#000000`
- Apply Rausch Red (`#ff385c`) only for primary CTAs and brand moments — it's the singular accent
- Use Airbnb Cereal VF at weight 500–700 — the warm weight range is intentional
- Apply the three-layer card shadow for all elevated surfaces
- Use generous border-radius: 8px for buttons, 20px for cards, 50% for controls
- Use photography as the primary visual content — listings are image-first
- Apply negative letter-spacing (-0.18px to -0.44px) on headings for intimacy
- Use circular (50%) buttons for carousel/navigation controls

### Don't
- Don't use pure black (`#000000`) for text — always `#222222` (warm)
- Don't apply Rausch Red to backgrounds or large surfaces — it's an accent only
- Don't use thin font weights (300, 400) for headings — 500 minimum
- Don't use heavy shadows (>0.1 opacity as primary layer) — keep them warm and graduated
- Don't use sharp corners (0–4px) on cards — the generous rounding (20px+) is core
- Don't introduce additional brand colors beyond the Rausch/Luxe/Plus system
- Don't override the palette token system — use `--palette-*` variables consistently

## 8. Responsive Behavior

### Breakpoints
| Name | Width | Key Changes |
|------|-------|-------------|
| Mobile Small | <375px | Single column, compact search |
| Mobile | 375–550px | Standard mobile listing grid |
| Tablet Small | 550–744px | 2-column listings |
| Tablet | 744–950px | Search bar expansion |
| Desktop Small | 950–1128px | 3-column listings |
| Desktop | 1128–1440px | 4-column grid, full header |
| Large Desktop | 1440–1920px | 5-column grid |
| Ultra-wide | >1920px | Maximum grid width |

*Note: Airbnb has 61 detected breakpoints — one of the most granular responsive systems observed, reflecting their obsession with layout at every possible screen size.*

### Touch Targets
- Circular nav buttons: adequate 50% radius sizing
- Listing cards: full-card tap target on mobile
- Search bar: prominently sized for thumb interaction
- Category pills: horizontally scrollable with generous padding

### Collapsing Strategy
- Listing grid: 5 → 4 → 3 → 2 → 1 columns
- Search: expanded bar → compact bar → overlay
- Category pills: horizontal scroll at all sizes
- Navigation: full header → mobile simplified
- Map: side panel → overlay/toggle

### Image Behavior
- Listing photos: carousel with swipe on mobile
- Responsive image sizing with aspect ratio maintained
- Heart overlay positioned consistently across sizes
- Photo quality adjusts based on viewport

## 9. Agent Prompt Guide

### Quick Color Reference
- Background: Pure White (`#ffffff`)
- Text: Near Black (`#222222`)
- Brand accent: Rausch Red (`#ff385c`)
- Secondary text: `#6a6a6a`
- Disabled: `rgba(0,0,0,0.24)`
- Card border: `rgba(0,0,0,0.02) 0px 0px 0px 1px`
- Card shadow: full three-layer stack
- Button surface: `#f2f2f2`

### Example Component Prompts
- "Create a listing card: white background, 20px radius. Three-layer shadow: rgba(0,0,0,0.02) 0px 0px 0px 1px, rgba(0,0,0,0.04) 0px 2px 6px, rgba(0,0,0,0.1) 0px 4px 8px. Photo area on top (16:10 ratio), details below: 16px Airbnb Cereal VF weight 600 title, 14px weight 400 description in #6a6a6a."
- "Design search bar: white background, full card shadow, 32px radius on container. Search text at 14px Cereal VF weight 400. Red search button (#ff385c, 50% radius, white icon)."
- "Build category pill bar: horizontal scrollable row. Each pill: 14px Cereal VF weight 600, #222222 text, bottom border on active. Circular prev/next arrows (#f2f2f2 bg, 50% radius)."
- "Create a CTA button: #222222 background, white text, 8px radius, 16px Cereal VF weight 500, 0px 24px padding. Hover: brand red accent."
- "Design a heart/wishlist button: transparent background, 50% radius, white heart icon with dark shadow outline."

### Iteration Guide
1. Start with white — the photography provides all the color
2. Rausch Red (#ff385c) is the singular accent — use sparingly for CTAs only
3. Near-black (#222222) for text — the warmth matters
4. Three-layer shadows create natural, warm lift — always use all three layers
5. Generous radius: 8px buttons, 20px cards, 50% controls
6. Cereal VF at 500–700 weight — no thin weights for any heading
7. Photography is hero — every listing card is image-first
