Cal.com — decoded design system

cal.com · light · modern · custom · deep decode — measured live

Cal.com's design system, decoded live by Mozaika: measured color roles, type scale, buttons with real hover/focus states, motion and the brand's own tokens.

Open in Mozaika →

This is a static, crawlable rendering for search & AI engines. The interactive version — filters, live decode console, copy & export — is at https://mozaika.design/decode/cal.com.

Decoded design system

Cal.com's decoded design system: background #F4F4F4, text #000000, accent #0000EE, link #111111, primary #374151; type scale h1 64px / h2 48px / body 16px; 4px spacing base; 8px base radius. The single interactive/action color is #0000EE — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Using these colors

• Action color #0000EE — the single interactive color; only on things you click or must notice, never large fills.
• accent #0000EE — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
• primary #374151 — a brand color — but the call-to-action uses #0000EE, not this.
• link #111111 — reads as a neutral UI color, not a link accent — verify against the reference (action = #0000EE).
• secondary #9CA3AF — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.

Typography

• Heading: Cal Sans
• Body: Inter
• Mono: Roboto Mono
• h1: 64px
• h2: 48px
• body: 16px

Spacing

• base unit: 4px
• scale: 2px, 4px, 6px, 8px, 10px, 12px, 16px, 20px, 24px, 28px

Radii

• base: 8px
• button: 12px

Shadow

rgba(255, 255, 255, 0.15) 0px 2px 0px 0px inset

Shadows (elevation)

• subtle: rgba(0, 0, 0, 0) 0px 1px 3px 0px, rgba(0, 0, 0, 0) 0px 0px 2px 0px
• card: rgba(19, 19, 22, 0.7) 0px 1px 5px -4px, rgba(34, 42, 53, 0.08) 0px 0px 0px 1px, rgba(34, 42, 53, 0.05) 0px 4px 8px 0px

Native design tokens

Button states (measured)

• primary focus: outline 1px auto rgb(16, 16, 16)

Motion choreography (measured)

Scroll reveal: 15 elements rest at opacity 0, translateY(-35px), animate in over 700ms.

Responsive (measured)

• breakpoints: 640px · 768px · 809px · 1024px · 1199px
• mobile (390px): hero 40px · nav inline

Install it

Drop this measured system into any shadcn/Tailwind project in one command:

npx shadcn add mozaika.design/r/decode/cal.com

registry item · or query it over MCP: get_design_system("Cal.com")

Export: DESIGN.md

# Cal.com — Design System

> light, modern, medium, custom — deep decode (measured live)

## Colors

| Role | Value |
|------|-------|
| bg | `#F4F4F4` |
| surface | `#E5E5E5` |
| border | `#CFCFCF` |
| text | `#000000` |
| text_muted | `#5C5C5C` |
| primary | `#374151` |
| accent | `#0000EE` |
| link | `#111111` |
| secondary | `#9CA3AF` |
| button_bg | `rgba(0, 0, 0, 0)` |
| button_text | `#0000EE` |

**Using these colors**

- **Action color** `#0000EE` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- **accent** `#0000EE` — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
- **primary** `#374151` — a brand color — but the call-to-action uses #0000EE, not this.
- **link** `#111111` — reads as a neutral UI color, not a link accent — verify against the reference (action = #0000EE).
- **secondary** `#9CA3AF` — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.
- **Page coverage** (full-page screenshot pixels): `#F4F4F4` 94.6% · `#C1C1C1` 5.4%

## Typography

- Heading: **Cal Sans** _(free fallback: Newsreader)_
- Body: **Inter**
- Mono: **Roboto Mono** _(measured)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 64px / 600 · lh 70px |
| h2 | 48px / 600 · lh 53px |
| h3 | 24px / 600 · lh 31px |
| body | 16px / 300 · lh 24px |
| small | 14px / 300 · lh 20px |

- Weight ladder: 300 · 400 · 500 · 600 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Cal Sans may be proprietary — safe free fallback: Newsreader (Google Fonts). Inter — free, on Google.

## Spacing
- base unit: 4px (inferred from the measured scale)
- measured scale: 2px, 4px, 6px, 8px, 10px, 12px, 16px, 20px, 24px, 28px — snap all gaps/padding to these

## Radius
- base: 8px
- button: 12px
- card: 100px
- pill: 9999px
- sharp: 2px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `rgba(0, 0, 0, 0)` / `#0000EE` | none | 12px | 8px 12px 8px 12px | 400 12px | rgba(255, 255, 255, 0.15) 0px 2px 0px 0px inset |
| secondary | `rgba(0, 0, 0, 0)` / `#0000EE` | none | 12px | 8px 12px 8px 12px | 400 12px | rgb(255, 255, 255) 0px 2px 0px 0px inset |

**States (measured, not guessed)**

- primary focus: outline `1px auto rgb(16, 16, 16)`

## Shadows (elevation)
- subtle: `rgba(0, 0, 0, 0) 0px 1px 3px 0px, rgba(0, 0, 0, 0) 0px 0px 2px 0px`
- card: `rgba(19, 19, 22, 0.7) 0px 1px 5px -4px, rgba(34, 42, 53, 0.08) 0px 0px 0px 1px, rgba(34, 42, 53, 0.05) 0px 4px 8px 0px`
- button: `rgba(255, 255, 255, 0.15) 0px 2px 0px 0px inset`

## Their own tokens (verbatim from :root)

| Token | Value |
|-------|-------|
| `--sj-tw-ring-color` | `rgba(59,130,246,.5)` |
| `--sj-tw-ring-offset-color` | `#fff` |
| `--sj-tw-ring-offset-width` | `0px` |

Prefer these names when extending their system — it's the brand's actual vocabulary.

## Motion choreography (measured)
- scroll reveal: 15 elements rest at opacity 0, translateY(-35px), animate in over 700ms (4 revealed during the drive).

Rebuild the timeline, not just the durations — order, delays and staggers above are the choreography.

## Components (measured)
- link: #111111 · no underline — hover rgba(17, 17, 17, 0.5)

## Responsive (measured)
- breakpoints: 640px · 768px · 809px · 1024px · 1199px
- mobile (390px): hero 40px · body 12px · nav: inline

## How to apply
Paste the Tailwind `@theme` (or CSS variables) as your base, then build each
section to its spec — verify every color, radius, and font against these tokens.
Hover/focus states, shadows and motion timings above are measured from the live page — match them exactly, don't re-guess them.

An automated reading of Cal.com's publicly-visible CSS (colors, fonts, spacing, motion) — not affiliated with cal.com. No screenshots stored. Removal requests: hello@mozaika.design.